N Gauge Forum

Product Reviews => Coupling Reviews => Topic started by: belstone on June 12, 2014, 06:48:48 am

Title: New coupler development (was Coupling survey)
Post by: belstone on June 12, 2014, 06:48:48 am
Hi everyone, I seem to have got a bit deeper into N gauge couplings than I expected, and now thinking about starting a small business specifically for this area. But first it would be very helpful to know a bit more about what N gauge modellers actually want from a coupling system.  So I have designed a short online survey, and Tank has very kindly given me permission to put the link up here. There are only 10 questions, it is completely anonymous and the more responses I get, the better.  Link is:

https://www.surveymonkey.com/s/7TYY9B8 (https://www.surveymonkey.com/s/7TYY9B8)

I'd also be grateful for any comments, either on the survey itself or on the whole issue of replacement coupling systems for British N gauge.

Many thanks, Richard
Title: Re: Coupling survey
Post by: 4x2 on June 12, 2014, 07:22:30 am
Good survey that !  :thumbsup:

Nice to see sensible questions that don't look like they were written by a lawyer !

I'm guessing that you have something in mind similar to the mt couplings but maybe with NEM compatibility ?
Title: Re: Coupling survey
Post by: Bealman on June 12, 2014, 07:32:40 am
Yes, a good survey. Sensible and relevant questions.
Title: Re: Coupling survey
Post by: Jack on June 12, 2014, 07:52:48 am
Boxes ticked and numbers listed.  :thumbsup:
Title: Re: Coupling survey
Post by: Greybeema on June 12, 2014, 08:08:04 am
I think the other piece of info you might need is how many/what proportion of coupler you might change...

I run a current day layout, so largely, I am running block trains and EMUs.  I wish to remotely uncouple/couple locomotives but the rake itself I leave permanently coupled. 

I would like a cheap, unobtrusive way of coupling the rake, without the need to uncouple (whilst on the layout) but with a better remote coupling solution at either end.

Hope that explains it.  I have toyed with the idea of mini trains couplers to the extent of buying a couple, assembling them to add to a loco but they are difficult to set up and (the ones I had at least) did not have the NRM pocket fitting and I bottled it.

Was thinking about the Dapol version unless something better comes along...




Title: Re: Coupling survey
Post by: belstone on June 12, 2014, 08:13:40 am
Ten responses already and the survey has only been up an hour.  Thank you everyone, keep them coming.  The survey is limited to 100 responses (any more and I would have to pay) but that should be enough to give me some information to work with.

NEM clip-in compatibility for MT couplings? I wish.  The main problem is that the NEM box is designed to allow vertical movement but not all of them permit horizontal movement.  For delayed-action knuckle couplings to work properly you need exactly the opposite. The NEM box is too shallow to take an MT split-shank coupler and adapter as a 'clip-in' fit, and just to make matters worse the design of boxes seems to vary even within the same manufacturer. Whichever committee (and I'm sure it was a committee) came up with the NEM box should be dragged through the streets by their ears.
Title: Re: Coupling survey
Post by: Caz on June 12, 2014, 08:25:30 am
Survey done, the only questions that I think that are missing are, what couplers have you experimented with and what are you currently using.

For instance, I've tried auto uncoupling with Rapido, Microtrains, MBM, B&B and Dapol Easi Shunt.  The MBM and B&B were good providing you fitted them one way round, that is a latch one end and the loop the other as having the complete mechanism on both ends of wagon made coupling and uncoupling difficult.  This is what stopped me using the likes of MBM & B&B as my layout is out and back so wagons get turned around so need ended up with mismatched ends.

Now gone back to Dapol Easi Shunts and very pleased with how they work and ease of fitting, uncoupling is 100% although the remote uncoupling in not as reliable as the MBM & B&B's and tends to recouple when pushed back especially over points.

Just my two pence worth.
Title: Re: Coupling survey
Post by: port perran on June 12, 2014, 08:52:47 am
All done.
Title: Re: Coupling survey
Post by: Dave Searle on June 12, 2014, 08:53:58 am
I also run post-privatisation stock with a large number in fixed rakes using Dapol Buckeyes where possible.  But there are also a large number of vehicles which need shunting either individually or in short rakes.  Currently these are planned to be DG fitted, using permanent small disc magnets for uncoupling.

I need closer coupling replacements for the older sprung Rapidos on some fixed-rake stock and an unobtrusive and reliable hands-off coupler for shunting.  If uncoupling is magnetic - then the the magnets also need to be unobtrusive.

Cheers,

Dave

Title: Re: Coupling survey
Post by: belstone on June 12, 2014, 09:21:41 am
Survey done, the only questions that I think that are missing are, what couplers have you experimented with and what are you currently using.

For instance, I've tried auto uncoupling with Rapido, Microtrains, MBM, B&B and Dapol Easi Shunt. 

Thanks for that. I've been through much the same process. Out of interest, what put you off using the Microtrains couplers?
Title: Re: Coupling survey
Post by: Chris in Prague on June 12, 2014, 09:23:55 am
All done; excellent survey. (I teach marketing research.) An uncoupling system that meets all the requirements listed would definitely be popular as uncoupling is the one area of railway modelling that is not easy to do remotely. However, there are many competing systems on the market which shows that a) there IS a market b) there is no overwhelmingly popular solution! So, there may well be a market opportunity for you. I do hope so.
Title: Re: Coupling survey
Post by: ozzie Bill. on June 12, 2014, 09:29:09 am
well done, good survey, well researched. Thanks for the opportunity. Bill.
Title: Re: Coupling survey
Post by: trainsdownunder on June 12, 2014, 09:36:34 am
Survey completed.

Will watch with interest.
Title: Re: Coupling survey
Post by: Newportnobby on June 12, 2014, 10:07:55 am
This 'ten thumbed bodger' has completed the survey :D
Title: Re: Coupling survey
Post by: Dave95979 on June 12, 2014, 10:22:41 am
do i use nem pockets    ummmm i have pockets in my trousers    i will have to look up nem pockets i think  :-[
Title: Re: Coupling survey
Post by: Vonzack on June 12, 2014, 10:26:55 am
Hi Belstone,

I tend to model modern era, so again I'm looking at fixed rakes of wagons, with the ability to remotely couple either end. At the moment, the majority of my stock uses either US Bachmann Dummy Knuckles for Rapido Spring Pockets or Dapol Dummy Knuckles for NEM Pocket wagons. I try to avoid the Dapol Easy-Shunt couplings as they are just 'huge', especially when compared to the US MT couplers.

Going forward I'd be more interested in a coupling solution which works with the NEM Pockets and involves some kind of vertical action, the need to have the knuckles move sideways to uncouple is I think what makes the Dapol solution larger than the MT, where the knuckle has physically move out of the way.

Cheers, Mark.
Title: Re: Coupling survey
Post by: Rabs on June 12, 2014, 10:59:11 am
Very interesting - I'll be looking forward to what you come up with :)
One point that might not be captured by your survey - how prototypical the couplers look (which is a slightly different question to how unobtrusive they are).  Dapol and Kadee knuckle couplers are fairly unobtrusive but they look completely wrong for steam era, so aren't worth the extra cost for me.  So I use DGs, as the least bad option.
Title: Re: Coupling survey
Post by: belstone on June 12, 2014, 11:02:29 am
41 responses now and some interesting trends emerging.  I'll share some of the key findings once the survey is complete. Thank you again everyone for your input.
Title: Re: Coupling survey
Post by: Roy L S on June 12, 2014, 11:45:21 am
Excellent survey, thoroughly relevant.

The only question I would have added is: -

"How important is it that you can switch back to Rapido couplings without major work?".

I know it asks whether you would be happy to saw/cut remove existing coupling mounts, but no question on it being reversible.

Hope this makes sense

Regards

Roy
Title: Re: Coupling survey
Post by: Dr Al on June 12, 2014, 12:00:05 pm
One comment I'd make (and I see others saying similar) is that for me any coupler change must be able to be changed back (and with no modification to the existing model) if I want to sell the model on in the future, as, like it or not, selling with standard rapidos is most desirable.

To me this is quite important as models are gradually updated and my fleet follows suit.

Cheers,
Alan
Title: Re: Coupling survey
Post by: belstone on June 12, 2014, 12:14:42 pm
The 'free' version of SurveyMonkey only allows you ten questions  :D But a good point, in an ideal world any change of couplers should be reversible, for both NEM and non-NEM stock. Small wonder that no-one has really cracked this problem yet. I'm in the middle of a very tedious job at work, and my head is buzzing with thoughts of little etched brass or nickel-silver parts. I don't think I'll make much progress on my layout for a while.
Title: Re: Coupling survey
Post by: PennineWagons on June 12, 2014, 12:37:40 pm
Done.  :angel:
I'm not really bothered about hands-free uncoupling, so I don't have any issue with standard Rapidos in that respect. What I don't like is the huge gap between any two Farish wagons/coaches when you couple them up, particularly in comparison with the gap between Dapol or Peco wagons. You can easily rectify this problem on the latest models with the NEM pockets, as Farish sell bags of short NEM Rapidos which you can easily fit, but for some reason they don't do a short version of the older standard coupling which fits in the spring-loaded pocket. So what I'd really like is a short standard Rapido to replace all the original Rapidos on my Farish stock, please, preferably at a reasonable price. I know that a guy has done these by 3D printing on Shapeways but they seem prohibitively expensive (knocking on £40 for 100 including postage if I remember rightly). There must be a gap in the market for something like this, I'm sure there'd be plenty of takers.
PW
Title: Re: Coupling survey
Post by: Dr Al on June 12, 2014, 12:40:51 pm
So what I'd really like is a short standard Rapido to replace all the original Rapidos on my Farish stock, please, preferably at a reasonable price.

Dapol use short shank rapidos and you can get them as spares via DCC supplies. I've used them on a Farish IC225 set to close up the coupling gaps.

Cheers,
Alan
Title: Re: Coupling survey
Post by: d-a-n on June 12, 2014, 06:37:22 pm
Good survey.
A bit of background which may compliment your research: I play trains and have an oval of Kato track with lots of sidings and bits of magnet track for shunting. I run mainly fixed rakes with easi shunts at each end. Some rakes have easi shunts within the rake to do a bit of shunting puzzling. My carriages tend to run as a core rake with easi shunts at each end. There are other single or 'multi purpose' carriages (BG, TPO etc) which can be shunted onto and out of different rakes and so these tend to have easi shunts on both ends. I'd like to add more shunts in but they're expensive and I don't think it'd change how I operate the train set.
I have cut up a few wagons to fit the NEM pockets to allow easi shunts but I'd be loathe to do this on any loco or item of rolling stock which is expensive in case it goes wrong! I like that converting the easi shunt back to rapido will be painless and that I've not had to convert much stuff which helps to keep a bit of resale value in my models.
I've been quite interested in the clear rapido couplings to put in the rakes too although having said that, I'm not that fussed about how big a rapido or easi shunt looks, as long as it keeps the train together and reliably uncouples when asked!
Title: Re: Coupling survey
Post by: PinkNosedPenguin on June 12, 2014, 08:32:05 pm
I use the Dapol easi-shunt couplings and am generally happy with them. but its their cost which is their main problem for me - I am loathe to change every single coupling when it costs £3.40 for couplers + £1.20 for NEM pockets PER VEHICLE (Hattons prices). That's £4.60 on top of the price of each individual wagon :(
Title: Re: Coupling survey
Post by: Roy L S on June 12, 2014, 08:41:38 pm
I use the Dapol easi-shunt couplings and am generally happy with them. but its their cost which is their main problem for me - I am loathe to change every single coupling when it costs £3.40 for couplers + £1.20 for NEM pockets PER VEHICLE (Hattons prices). That's £4.60 on top of the price of each individual wagon :(

They are pretty intricate pieces of kit and I suspect much of the price is in the cost of assembly.
Title: Re: Coupling survey
Post by: Chris in Prague on June 12, 2014, 08:56:43 pm
To be anywhere near statistically valid 100 replies would be the minimum but, realistically, 50 is a good number to aim for. 8-)
Title: Re: Coupling survey
Post by: elmo on June 12, 2014, 09:42:30 pm
I will doubtless be in the minority, but here goes -
 
I have model railways in 3 scales both indoors and in the garden. The larger scales use chain couplings and i use a hook. In n gauge the use of chains is out of the question for the average eye sight. I therefore use the standard coupling and uncouple with a 'shunters pole' by lifting one of the couplings.

Hands free operation has never meant much to me other than extra expense in layout building. I have also found it rather annoying that all the model railway mags have seemingly spent the past 30 years suggesting that if you use the 'big hand from the sky' then you are not a real railway modeller. What a delight therefore that a couple of years ago I noticed for the first time at an exhibition that uncoupling by hook and hand from sky outnumbered hand free shunting.

Dealing specifically with N gauge, I do get really fed up when I read reviews of locos and rolling stock and reference is made to 'that large coupling'. If anything, I will venture to suggest that N gauge has been blessed with the best of the mass produced couplings (I think tension locks are horrible in both looks and operation).
However, the N gauge coupling is reliant on how it has been done. To me the hands down winner is the Peco variant. The elsie allows a very light touch to activate coupling up without the whole wagon/train being pushed along. They also allow for 'buffering up' due to the forward/backward movement that the design allows. Best of all the distance between the wagons is more prototypical. Also, if you insist they can be made hands free.

The spring mounted coupling looses most of the advantages of the peco version. Coupling up can be done with alight  touch but is hit and miss. The Springs though can be removed and the use of a staple or a peco/gaugemaster lift arm can be used to bring the coupling parallel thus making it similar to the elsie.

To me, what has damaged the standard n gauge coupler is the way that the NEM pocket has been designed into n gauge stock. It is clear to me that the NEM has been designed to make alternative couplings work but has not paid any attention to the standard coupler. This is just shoved in the NEM pocket to sell the wagon with a standard coupling that in most cases puts the distance between joined wagons to ridiculous length. An example being Dapols fine siphons. the first spring coupling very good. I get some more via the dapol club and they had NEM's. the distance between wagons was stupid beyond belief. The NEM pocket has in affect stopped be buying n gauge stock which I would have normally spent money on.

Tin hat ready!!

Elmo
Title: Re: Coupling survey
Post by: belstone on June 12, 2014, 10:17:34 pm
Elmo, I'm going to partly agree with you, but for different reasons.  I fear the NEM coupler pocket has condemned us to another twenty years of inadequate, unreliable N gauge couplings. The big problem I have with it is that it is designed for vertical movement, not lateral.  That makes it fundamentally unsuited to any type of delayed-action knuckle coupling.  There are good reasons why a lot of people have had trouble getting the delayed uncoupling facility on the Dapol EasiShunts to work properly, and it is all down to the boxes that they are clipped into.

I have just had a look at three recent release Farish items - 2MT, horsebox and cattle van. All three have different pocket designs, and none will allow an Easishunt coupler to be pulled off-centre by magnetic attraction.  No deflection, no remote uncoupling.

I agree with you that the  Peco 'Elsie' coupling is by far the best of the various Rapido types, and it is a real shame that no other manufacturer adopted it. I would guess this was down to having to pay royalty fees to Peco, whereas Arnold allowed anyone to use their spring-loaded design for free.
Title: Re: Coupling survey
Post by: PinkNosedPenguin on June 12, 2014, 10:32:56 pm
I have just had a look at three recent release Farish items - 2MT, horsebox and cattle van. All three have different pocket designs, and none will allow an Easishunt coupler to be pulled off-centre by magnetic attraction.  No deflection, no remote uncoupling.
Are you suggesting the easi shunts do not uncouple on these items? I disagree. They uncouple on ALL my stock. Delayed uncoupling is not reliable for me, but basic hands-free uncoupling is not a problem. The coupler shaft does not need to move for this - just the sprung knuckle section. To me these couplings are a VAST improvement over those horrible rapidos that are basically not fit for purpose - they often don't couple reliably, let alone uncouple . . .
Title: Re: Coupling survey
Post by: belstone on June 12, 2014, 10:48:04 pm
Sorry, I meant delayed uncoupling, not remote. The Dapols uncouple just fine. I've tested them. But the delayed uncoupling feature is entirely dependent on the design of pocket they are fitted to.  As far as I can gather it works on most Dapol stock (unsurprisingly) but on a Farish 2MT, for example, I don't see how it can physically work. It's hard to judge how important delayed uncoupling is to people: it's one of those features that you probably don't think very important until you've tried it. Even then it is only really relevant to branch line terminus and goods yard layouts, where complex shunting operations provide almost all the operational interest.
Title: Re: Coupling survey
Post by: belstone on June 13, 2014, 09:37:11 am
77 responses now which is far more than I expected. I am deeply grateful to everyone who took the time to respond.  The pattern of answers hasn't changed much since the first 20, so I think I am safe to draw some conclusions.  As promised, here are a few of the more interesting findings:

90% of you are still using Rapido couplings - but often in conjunction with other types. Almost a third of you are using Dapol Easi-shunts, which is higher than I expected.  Looks like a lot of people are running fixed rakes with Rapidos between the vehicles and Dapols on the end vehicles and locos.  Around 13% are using Micro-Trains knuckles, 10% are 'finescale' (B&B etc).

You like to shunt. Over half of you are regularly shunting on your layouts, and another 30% do so occasionally.

Two thirds of you would definitely be interested in hands off, delayed action uncoupling, and most of the rest would consider it.

You really want reliability, closely followed by ease of fitment. Cost is less important - you'll happily pay for something if it works. The fact that so many of you are using Dapols at £6 a vehicle proves that.

Four in five of you would modify a loco to fit different couplings, but most of you would only do so if you had a clear set of instructions to follow. 

Several of you admit to being ten-thumbed bodgers :D

And not directly coupling-related, but the most popular area of modelling interest by a mile is steam/diesel transition era. So where are all those early 60s layouts?

I now have to try and work out what this all means...
Title: Re: Coupling survey
Post by: Newportnobby on June 13, 2014, 10:00:27 am
Yup - I guess that all just sums me up ;)
Title: Re: Coupling survey
Post by: belstone on June 13, 2014, 10:02:10 am
Here's my assessment of where we are in N gauge as regards couplers:

Rapido.  For - free with every N gauge vehicle.  Against - bulky, needs a good shove to couple up, hands free uncoupling is difficult, no delayed uncoupling facility.

Dapol Easi Shunt. For - clip in replacement for NEM couplings, couples up easily, magnetic uncoupling works well if properly set up. Against - delayed uncoupling unreliable, trip pin needs careful adjustment, knuckle springs are vulnerable, needs special magnets to pull couplers sideways rather than down. Accidental self-uncoupling over magnets especially with light, free-rolling vehicles. Not especially cheap.

Finescale (DG, B&B etc). For - very cheap, can use hidden under-track electromagnets, good delayed uncoupling, flat mounting plate makes easy fitting on most models.  Against - incredibly fiddly to assemble and set up, designed for body mounting at buffer beam height so unsuitable for sharp curves. Coupling up can be tricky unless you leave the loop off one end of each vehicle.

Micro-Trains. For - been around for many years, wide range, fairly easy to convert spring-loaded Rapidos, works very well when set up properly, bit cheaper than Dapols.  Against - fiddly to assemble, need very careful fitting and setting up, same issue with magnets and accidental self-uncoupling as the Dapol couplers, top of knuckle is at buffer beam height which gives problems with sharp curves, sudden gradient changes and wonky track. Not compatible with NEM pockets, designed for American models, little or no information on how to fit to British vehicles.

Comments welcome...
Title: Re: Coupling survey
Post by: Ben A on June 13, 2014, 12:57:24 pm

Hello Belstone,

In your analysis above I agree with most of the points, however I would say that the "finescale" options are not especially easy to fit:  not only do they often require shimming and a lot of height adjustment to achieve reliability, but also they often require that the model be permanently altered.

I looked at couplers myself before - and even invested some money in tooling - but the results were unsatisfactory.  Essentially, the core problems are:

1)  Everything is very small and fiddly. So assembly is difficult, time consuming, or costly.  Or all three.
2)  If it's big enough to be easy to assemble and fit, it looks terrible.
3)  Everyone wants a new coupler, but no one wants to damage their trains.
4)  They also expect any new coupler to be easy to fit to every model they own, regardless of existing couplers.  Without, of course, requiring them to damage their trains.
5)  And no one wants to pay for a decent, new coupler.
5)  If British stock didn't try to combine buffers with train set curves then it'd be easy.

Good luck - I'd be really interested in any design you come up with!

cheers

Ben A.
Title: Re: Coupling survey
Post by: belstone on June 13, 2014, 01:46:08 pm
Thanks Ben, I think that's about the size of it.  The perfect coupler system would be vertical action (so it can work with those poxy NEM pockets) but with some lateral movement as well to cope with tight curves, magnetically operated (using under track electromagnets), with delayed uncoupling, unobtrusive yet robust, made in a variety of lengths to suit everything from 2mm finescale to No.1 radius Setrack reverse curves, and available as a clip-fit for both NEM and older Rapido boxes. And cost about a pound per pair :D

Title: Re: Coupling survey
Post by: Ben A on June 13, 2014, 02:01:48 pm

Indeed.

On our club layout we shunt in the steel terminal using Dapol easi shunt couplers. They work with almost 100% reliability - and when they don't it's usually down to operator error. 

They're fitted on 4 locomotives and 8 wagons - but at one end only, making a total of 6 pairs of couplers.

The amount of operational flexibility, opportunities and enjoyment they've given is well worth the £18 they cost to buy.

Cheers

Ben A.
Title: Re: Coupling survey
Post by: Karhedron on June 13, 2014, 02:05:37 pm
And cost about a pound per pair :D
A pound a pair? Do you think we are made of money. They should come free with packets of cornflakes. :p

But in all seriousness, I think that you and Ben have summed up the state of play quite neatly. There are a lot of conflicting requirements with people not looking to spend too much money to solve them.

I seem to recall seeing someone doing some very impressive demonstrations on DCC using memory wire. It solved most of the problems but was not cheap and only worked on DCC.
Title: Re: Coupling survey
Post by: Roy L S on June 13, 2014, 02:13:21 pm

Indeed.

On our club layout we shunt in the steel terminal using Dapol easi shunt couplers. They work with almost 100% reliability - and when they don't it's usually down to operator error. 

They're fitted on 4 locomotives and 8 wagons - but at one end only, making a total of 6 pairs of couplers.

The amount of operational flexibility, opportunities and enjoyment they've given is well worth the £18 they cost to buy.

Cheers

Ben A.

Hi Ben

Cost is a big issue using easi-shunts but you can see why they are so expensive they must be very time consuming to assemble.

I tend to mitigate the cost a little by putting one Easi-shunt on a wagon and leave the Rapido on the other end. Running in pairs means you can run with either on the outer end by reversing them best of both worlds in some ways.

Buying the 10 packs is also quite a bit more cost-effective than the pairs.

Regards

Roy

Title: Re: Coupling survey
Post by: SmileyFace on June 13, 2014, 02:19:04 pm

Indeed.

On our club layout we shunt in the steel terminal using Dapol easi shunt couplers. They work with almost 100% reliability - and when they don't it's usually down to operator error. 

Ben A.
I'd really like to know how you achieve this. The 'uncouple' function when over the magnet works just fine but the sideways movement of the knuckles is always insufficient to allow 'delayed uncouple' when pushed away from the magnet. I've tried positioning the actuating pins as close to the track centre as possible so as to maximise the 'throw' of the knuckle but the physical size of the knuckles will always ensure they will re-engage once pushed clear of the magnet. In my experience coupling-up is not always first-time either.

Any guidance would be appreciated.
Cheers
SF
Title: Re: Coupling survey
Post by: Karhedron on June 13, 2014, 02:27:44 pm
It is not the throw of the knuckle that matters. The whole arm needs to swing sideways for the delayed action shunting to work. In order for this to happen, there needs to be room. Normally you need to uncouple, pull the engine away from the train slightly to allow both coupling arms to fully deflect and then shunt into the train again.

This is affectionately known as the "micro-trains shuffle" across the pond for obvious reasons.

If you want to see the position the arms need to swing into for delayed-action shunting, take a look at the photos I put on RMWeb a couple of years ago when I first experimented with them. You can use them as comparisons for your own couplings. If yours do not move into the positions that mine go to in the photos, try and see what is impeding them.

The last 2 photos in particular are important. The arms need to deflect enough so that the 2 straight sections of the couplers are central enough. These are what stop the knuckles coupling up again once you move away from the points.

http://www.rmweb.co.uk/community/index.php?/topic/48728-dapol-easi-shunt-magnetic-couplings-in-n/?p=570075 (http://www.rmweb.co.uk/community/index.php?/topic/48728-dapol-easi-shunt-magnetic-couplings-in-n/?p=570075)
Title: Re: Coupling survey
Post by: belstone on June 13, 2014, 02:34:40 pm
I think coupler systems have only really become an issue due to the dramatic improvement in loco mechanisms over the last few years.  Most of the old stuff didn't give reliable enough slow speed running to make complex shunting operations possible, so N gauge has tended to develop around continuous run, fixed rakes, watching the trains go by.  Compared to 4mm there are very few branch terminus or goods yard layouts in N - without reliable slow speed running and a good coupler system, an end to end layout isn't much more than a diorama.
Title: Re: Coupling survey
Post by: SmileyFace on June 13, 2014, 02:51:34 pm
It is not the throw of the knuckle that matters. The whole arm needs to swing sideways for the delayed action shunting to work. In order for this to happen, there needs to be room. Normally you need to uncouple, pull the engine away from the train slightly to allow both coupling arms to fully deflect and then shunt into the train again.

This is affectionately known as the "micro-trains shuffle" across the pond for obvious reasons.

If you want to see the position the arms need to swing into for delayed-action shunting, take a look at the photos I put on RMWeb a couple of years ago when I first experimented with them. You can use them as comparisons for your own couplings. If yours do not move into the positions that mine go to in the photos, try and see what is impeding them.

The last 2 photos in particular are important. The arms need to deflect enough so that the 2 straight sections of the couplers are central enough. These are what stop the knuckles coupling up again once you move away from the points.

[url]http://www.rmweb.co.uk/community/index.php?/topic/48728-dapol-easi-shunt-magnetic-couplings-in-n/?p=570075[/url] ([url]http://www.rmweb.co.uk/community/index.php?/topic/48728-dapol-easi-shunt-magnetic-couplings-in-n/?p=570075[/url])

Hmm - thanks for that and the link to your excellent photos. I've only used either the Dapol, Microtrains or Kato magnets so maybe therein lies the problem. The whole coupling doesn't move sideways at all - it's just the knuckles that deflect and that movement is insufficient for the delayed uncouple action. Most of my couplings are such a tight fit in their pockets that they are unlikely to move sideways anyway.
Title: Re: Coupling survey
Post by: belstone on June 13, 2014, 02:53:28 pm
It is not the throw of the knuckle that matters. The whole arm needs to swing sideways for the delayed action shunting to work.

And that's the problem.  The NEM standard for coupler pockets (which is helpfully only available in French and German) suggests that the pocket should pivot to allow lateral movement, but doesn't set any specific requirement.  The coupler itself clips firmly into the pocket in a way which will not and cannot allow the coupler to move sideways in the pocket. Ideally the pocket needs to have a pivot and very light sprung centring action, but Farish don't seem to employ anyone who can read French or German. So the 2MT for example has pockets mounted rigidly to the pony truck and tender chassis, and the Dapol delayed uncoupling function will not work on that loco however strong your magnets are.

I don't possess any Dapol stock, presumably they have the type of pockets required to make the delayed action work properly. But if Dapol couplers only work 100% reliably when fitted to Dapol products, they aren't as useful as we all hoped they would be.  I don't blame Dapol: the NEM standard seems to have assumed that Rapido would be the standard N gauge coupler for evermore, and Dapol have done the best they can with what they have to work with. (Although it would have helped a bit if the knuckle were smaller, so that the tongue could be closer to the vehicle centre line.)
Title: Re: Coupling survey
Post by: Karhedron on June 13, 2014, 02:57:34 pm
Hmm - thanks for that and the link to your excellent photos. I've only used either the Dapol, Microtrains or Kato magnets so maybe therein lies the problem. The whole coupling doesn't move sideways at all - it's just the knuckles that deflect and that movement is insufficient for the delayed uncouple action. Most of my couplings are such a tight fit in their pockets that they are unlikely to move sideways anyway.
I have to admit, I used the rare earth magnets to save money and avoid me having to dig up track and fit the Dapol magnets. I assumed that the rare earth ones would not be as good as they were smaller and not designed specifically for the task but perhaps they work better than the Dapol own-brand ones.  :-\

My other question is what stock are you using? My experiments have been Dapol couplers in Dapol stock. I have heard that some of the older Farish NEM pockets are a very tight fit which might impede the swing action of the coupler. Apparently their latest releases have fixed this issue and the NEM pocket is the correct size.
Title: Re: Coupling survey
Post by: talisman56 on June 13, 2014, 03:02:02 pm

And not directly coupling-related, but the most popular area of modelling interest by a mile is steam/diesel transition era. So where are all those early 60s layouts?


One (still under (re-)development) described in the thread below: vvv

I have a small supply of Dapol conversion kits and working and dummy Dapol couplings which I was going to start converting my fleet with, but the hacking about that will be needed on the non-NEM stock has brought me to a pause at the moment. I will be very interested to see what you come up with that will be different and meet all the criteria that your survey reveals.

Yes I did answer it, and although not quite a ten-thumbed bodger, still want to retain some resale value in my stock...
Title: Re: Coupling survey
Post by: Karhedron on June 13, 2014, 03:03:54 pm
I don't possess any Dapol stock, presumably they have the type of pockets required to make the delayed action work properly. But if Dapol couplers only work 100% reliably when fitted to Dapol products, they aren't as useful as we all hoped they would be.  I don't blame Dapol: the NEM standard seems to have assumed that Rapido would be the standard N gauge coupler for evermore, and Dapol have done the best they can with what they have to work with. (Although it would have helped a bit if the knuckle were smaller, so that the tongue could be closer to the vehicle centre line.)
I suppose a possibility is to remove the Farish NEM pockets and replace them with the Dapol ones (which they helpfully sell separately). I can confirm that the Dapol pocket does permit sideways movement. I guess it is not Dapol's fault if Farish have not followed the NEM standard.

If you prefer not to modify your stock then the other option is to scatter uncoupling magnets around your shunting yards. If you use the small rare earth magnets that I have used, it is not very expensive as they work out at pennies each when bought in bulk. Delayed action is not needed so much if you have magnets in convenient locations.
Title: Re: Coupling survey
Post by: SmileyFace on June 13, 2014, 04:08:55 pm
I have to admit, I used the rare earth magnets to save money and avoid me having to dig up track and fit the Dapol magnets. I assumed that the rare earth ones would not be as good as they were smaller and not designed specifically for the task but perhaps they work better than the Dapol own-brand ones.  :-\

My other question is what stock are you using? My experiments have been Dapol couplers in Dapol stock. I have heard that some of the older Farish NEM pockets are a very tight fit which might impede the swing action of the coupler. Apparently their latest releases have fixed this issue and the NEM pocket is the correct size.
All the magnets work well for delayed uncoupling of Microtrains couplings but they are somewhat smaller than the Dapol couplings.

Stock is a mixture of Dapol and Farish. For example, my Dapol 67's couplings will definitely not move sideways over a track magnet and neither do my Dapol CargoWaggon couplings. My latest Farish DRS coach couplings are similarly very tight and only the knuckles will move.

I would dearly like to adopt Dapol couplings for ease of fitment but the lack of the delay feature makes me reluctant. Yes, you can use lots of magnets around the layout but if you always have to leave stock over the magnet then it has to be pushed well clear before it can be recoupled.
Title: Re: Coupling survey
Post by: Karhedron on June 13, 2014, 08:48:54 pm
Even in Dapol pockets, you coupling arms do not swing?  :hmmm:

Probably a silly question but are you sure the couplings are pushed all the way into the pockets until they click? The pivot point needs to be seated in the small hole provided for the purposes. If it is not pushed all the way home, I can imagine that it might be too stiff to swing.

The reason I ask is that the arms swing on all my Dapol stock so it seems strange that they will not swing at all on yours.
Title: Re: Coupling survey
Post by: BobB on June 13, 2014, 09:48:31 pm
Given that almost every (or should that be every) British outline vehicle is currently supplied with a working coupling, perhaps we should be looking at the simplest replacement from what we have.

How about chopping off the coupling at the end of the shaft (using either saw or maybe just a very sharp knife).

The existing Dapol coupling could be modified to have a socket with a square hole, tapered internally to suit different manufacturers sizes and just a spot of glue inserting the magnetic coupler over the square shaft. I think we could all cope with that. Those who want close coupling can cut the shaft a bit shorter.

OK, still a bit large but quite a bit better than what we have.

How about it Dapol ?
Title: Re: Coupling survey
Post by: belstone on June 13, 2014, 10:35:36 pm
just a spot of glue

I'm not sure the plastic used in most Rapidos is very glue-friendly. But I like your thinking. Surprising that Dapol haven't yet made an EasiShunt with a Rapido T-shank.  Perhaps they're working on it.
Title: Re: Coupling survey
Post by: Chris in Prague on June 14, 2014, 06:32:00 am
77 responses now which is far more than I expected. I am deeply grateful to everyone who took the time to respond.  The pattern of answers hasn't changed much since the first 20, so I think I am safe to draw some conclusions. 

Yes, well-done to you and everyone who answered. 77 replies (and more, now?) is an excellent result and tells us that there is a lot of interest in the topic. Also, the fact that the pattern of answers hasn't changed much since the first 20 shows us that, from those who are interested enough to reply, it is reasonable to draw some conclusions.

I am watching this thread with great interest but still don't plan on changing my rolling stock's couplings as a priority.
Title: Re: Coupling survey
Post by: SmileyFace on June 14, 2014, 11:42:09 am
Even in Dapol pockets, you coupling arms do not swing?  :hmmm:

Probably a silly question but are you sure the couplings are pushed all the way into the pockets until they click? The pivot point needs to be seated in the small hole provided for the purposes. If it is not pushed all the way home, I can imagine that it might be too stiff to swing.

The reason I ask is that the arms swing on all my Dapol stock so it seems strange that they will not swing at all on yours.
When pushed with a finger the Dapol coupling's arm will swing but not when under the control of a track magnet.

As the magnets are only 6.5mm wide (so as to clear the wheel flanges) the maximum swing in either direction, when everything is perfectly set up, is only ever going to be 3.25mm. This just doesn't seem to be  enough for both the knuckle to be fully deflected sideways and then for the arm to swing in addition to this. As your rare earth magnets are mounted close up to the rails maybe that's why yours are ok and swing both the knuckles and the arm, (they may also be stronger magnets too).

Thanks  for your interest anyway.
SF
Title: Re: Coupling survey
Post by: belstone on June 14, 2014, 12:29:02 pm
I had wondered whether very strong magnets mounted on the outer edge of the rails might work, with the tops a little above rail height. I don't have any suitable magnets to try.
Title: Re: Coupling survey
Post by: Newportnobby on June 14, 2014, 01:28:53 pm
I had wondered whether very strong magnets mounted on the outer edge of the rails might work, with the tops a little above rail height. I don't have any suitable magnets to try.

That would certainly make fitting magnets much easier and avoid carving sleepers from the track. I'd be interested to know if anyone has successfully experimented with this :hmmm:
Title: Re: Coupling survey
Post by: NZModeller on June 14, 2014, 01:38:18 pm
Hi Everyone,

I've converted to Dapol magnetic couplings and on the whole I'm pretty pleased with them, however, I have basically given up on the delayed action as there are many factors that get in the way of this being reliable:

Curves before magnets
Short wheelbase stock
Short wheelbase locos i.e. shunters!
Sprung close coupling mechanisms

That's pretty much everything I want to shunt with.

I have, however found a way to retrofit the Dapol magnets under Peco code 55 so they are reliable and invisible so it's just a case of putting them in the right places.

Here's how

Remove 8 sleepers including all the plastic runners from the grooves in the rail and the ballast.
Fix the magnet in the gap temporarily and check for operation, adjust the height if necessary.
Take a spare section of code 55 and turn rails down, CAREFULLY pare off 8 sleepers flush with the rail (you may need to build a jig to do this. You should be left with a "ladder" of 8 sleepers around .5mm thick, complete with the runners between. The ladder can be slid into the grooves in the rails above the magnet and the track re-ballasted.  I've done about 10 of these and they are impossible to spot in general operation so you will need a marker of some kind.

Also, has anyone used the Etched Pixels NEM bar couplings for permanently coupled rakes? HST in particular.

Peter
Title: Re: Coupling survey
Post by: Karhedron on June 14, 2014, 07:03:54 pm
Surprising that Dapol haven't yet made an EasiShunt with a Rapido T-shank.  Perhaps they're working on it.
Part of the problem is height. NEM specifies the height but rapido boxes can be at any height. The Dapol couplings need to be at the same height as each other to operate reliably. Rapidos can do it because the shape of the coupling hook will compensate for height differences but then it does not need to uncouple remotely.

That is why Dapol produced NEM pocket conversion kits rather than a Rapido version. Dave Jones said that attempts to make a Rapido version of the Easi shunt were not reliable enough.
Title: Re: Coupling survey
Post by: Chinahand on June 14, 2014, 08:44:39 pm
Hi Richard,

I've just completed your survey but would like to add a couple of clarifications.

The last question refers to the Micro-trains couplers which I did try but found that they required just too much 'surgery', particularly to steam locos, which I was not happy to do so I abandoned them.

Secondly, for permanently connected rakes of carriages or wagons I'm using the Tomix Scharfenberg couplers which I get from DCC Supplies and are a simple straight replacement for Rapidos but are far less intrusive and give much closer coupling. http://www.dccsupplies.com/shop/product_info.php?products_id=3086 (http://www.dccsupplies.com/shop/product_info.php?products_id=3086)
Title: Re: Coupling survey
Post by: Greybeema on June 15, 2014, 09:29:52 am
Chinahand,

Using the Sharfenberg couplers - what radius of track will they go around?

EP same question ref your Bar Couplings..
Title: Re: Coupling survey
Post by: Chinahand on June 15, 2014, 12:25:31 pm
Not sure what their minimum radius is but the minimum on my layout is 15" and they have no problem dealing with that. However, I'm guessing that, because they give quite close coupling, smaller radii could result in buffer locking.
Title: Re: Coupling survey
Post by: belstone on June 15, 2014, 08:09:17 pm
My wife thinks I am obsessed with couplings. She is probably right. Anyway, at the end of a day of fiddling around with various materials, and rather to my surprise, I have two working prototypes fitted to short wheelbase wagons - one NEM, the other T-shank. Obviously I'm not going to go into design details at this stage, but features include hands off uncoupling and delayed uncoupling, also vehicles can be easily uncoupled from each other by hand and removed from the track. They use ordinary bar magnets either flush with the sleepers or buried in the track bed. Coupling force is minimal, and with these rather crude prototypes (which have an awful lot wrong with them in constructional terms) I'm getting about 90% reliability in coupling, uncoupling and delayed uncoupling. And they don't show any tendency to self-uncouple when drawn over the magnets. There's plenty of clearance under the bufferbeam so they should be fine on tight curves.

However, there are a few issues, and I would be interested to know what people think about the following:

1. They are fairly height-sensitive, which means the shanks have to be mounted rigidly in the pockets with no vertical movement.  I think NEM pockets should be OK provided the shank dimensions are correct, the pocket is fitted at the right height (ha ha) and there's no slop between the pocket and its mounting, but the T-shank version will almost certainly need to be glued in, which means the conversion isn't easily reversible. I suppose it depends what glue you use. I might be able to tweak the design so they cope with larger height differences, but the shank really needs to be rigid in the vertical plane for them to couple reliably.

2. Distance between the vehicles is about the same as Rapidos, and there isn't a lot of scope to shorten it due to the design.  So you aren't going to get the kind of prototypical close coupling that can be achieved with short-shank knuckle couplers.

3. In an ideal world I would have the components injection-moulded in a suitable plastic, but tooling costs rule that out straight away.  I don't think the shape and size will lend itself to 3D printing although I don't really know just what is possible with that technology.  So we are probably looking at a kit, including cast whitemetal and etched parts, which will require two or three very small holes drilling in the right places (dimples in the castings to mark the positions) and steel wire bending accurately to shape, probably with a bending jig included in the etched component fret.  I would reckon between £2 and £3 a pair, and 10 minutes per coupling to assemble once you've done the first couple.

4. Long shank variants are problematic.  It is easy enough to cater for standard length Rapidos (NEM or T shank) which probably cover 90% of applications.  But I know there are some oddball Rapido variants out there, and the one that this design definitely won't work with is the extra-long T-shank in a fixed pocket which I have seen occasionally on long wheelbase wagons with long end overhangs (1970s Minitrix German stuff, mainly). Swivelling pockets (like the Farish horsebox) are fine provided there's no vertical slop in the mechanism. I'd be interested to know of other long-shank couplings, especially on current or recent production stock.

I can't quite believe I've come up with something that works, especially as it is so simple in concept. There must be a catch - maybe someone has already patented the design I have in mind. If they haven't, I think I might.
Title: Re: Coupling survey
Post by: johnlambert on June 15, 2014, 08:52:54 pm
Sounds very promising.  Are you going to get some other people to test your design?

Looking forward to hearing how other people get on with it, or any other news you have.
Title: Re: Coupling survey
Post by: belstone on June 15, 2014, 08:59:25 pm
Sounds very promising.  Are you going to get some other people to test your design?

Looking forward to hearing how other people get on with it, or any other news you have.

Early days yet, and I'm trying to work out how to take this forward. I think the next stage is to get a test etch done (I'm fed up with filing hooks out of brass sheet), make up some fully functional prototypes from brass and fit them to a dozen assorted wagons. Build a small shunting layout including Setrack points, sharp reverse curves and maybe an incline with really fearsome gradient changes. And if they cope with all that, I might think I'm onto something.
Title: Re: Coupling survey
Post by: johnlambert on June 15, 2014, 09:54:36 pm
Sounds like a good plan!
Title: Re: Coupling survey
Post by: Caz on June 15, 2014, 09:57:34 pm
Looking forward to hearing more, sounds very interesting.  One question, will they be exactly the same coupling on both end of the wagon or be handed as that is why I gave up with the like of MBM and B&B's etc.
Title: Re: Coupling survey
Post by: belstone on June 15, 2014, 10:07:45 pm
Looking forward to hearing more, sounds very interesting.  One question, will they be exactly the same coupling on both end of the wagon or be handed as that is why I gave up with the like of MBM and B&B's etc.

Same on both ends. I wouldn't accept a coupling that only worked one way round.
Title: Re: Coupling survey
Post by: Bealman on June 16, 2014, 07:40:46 am
This is indeed most interesting. I wish you every success with the project! Good luck with your testing programme, which sounds pretty thorough to me!  :thumbsup:
Title: Re: Coupling survey
Post by: Karhedron on June 16, 2014, 09:49:57 am
Whilst I am generally happy with Dapol Easi-shunts, I appreciate they are not a perfect solution so I will be wating this thread with interst. Well done for having the motivation to tackle a tricky subject.  :thankyousign:

1. They are fairly height-sensitive, which means the shanks have to be mounted rigidly in the pockets with no vertical movement.  I think NEM pockets should be OK provided the shank dimensions are correct, the pocket is fitted at the right height (ha ha) and there's no slop between the pocket and its mounting, but the T-shank version will almost certainly need to be glued in, which means the conversion isn't easily reversible. I suppose it depends what glue you use. I might be able to tweak the design so they cope with larger height differences, but the shank really needs to be rigid in the vertical plane for them to couple reliably.
In this regard they have the same restriction as the Dapol couplers. One simple solution would be to fit the stock with NEM pockets. That way the Rapidos can be reinstated if necessary.

2. Distance between the vehicles is about the same as Rapidos, and there isn't a lot of scope to shorten it due to the design.  So you aren't going to get the kind of prototypical close coupling that can be achieved with short-shank knuckle couplers.
It depends where it is used. If you just have them fitted to locos and the ends of a rake, this is not really a problem. You can still use short-shank knuckles within the rake to keep it closely coupled.

3. In an ideal world I would have the components injection-moulded in a suitable plastic, but tooling costs rule that out straight away.  I don't think the shape and size will lend itself to 3D printing although I don't really know just what is possible with that technology.  So we are probably looking at a kit, including cast whitemetal and etched parts, which will require two or three very small holes drilling in the right places (dimples in the castings to mark the positions) and steel wire bending accurately to shape, probably with a bending jig included in the etched component fret.  I would reckon between £2 and £3 a pair, and 10 minutes per coupling to assemble once you've done the first couple.
People have printed rapido and NEM couplings quite successfully on Shapeways although without knowing what your coupling looks like, I do not know if it would work. Also you would need to work up the designs in 3D with a CAD package. Obviously I would prefer a ready made solution because I am lazy. ;) But I would certainly not rule out a kit if the design is a good one.

4. Long shank variants are problematic.  It is easy enough to cater for standard length Rapidos (NEM or T shank) which probably cover 90% of applications.  But I know there are some oddball Rapido variants out there, and the one that this design definitely won't work with is the extra-long T-shank in a fixed pocket which I have seen occasionally on long wheelbase wagons with long end overhangs (1970s Minitrix German stuff, mainly). Swivelling pockets (like the Farish horsebox) are fine provided there's no vertical slop in the mechanism. I'd be interested to know of other long-shank couplings, especially on current or recent production stock.
I am inclined to think that a solution which is good for 90% of stock is good enough. For people who have unusual items in their collection, they could modify them or use a translator vehicle with your enw couplings at one end and a regular rapido at the other.
Title: Re: Coupling survey
Post by: SmileyFace on June 16, 2014, 10:56:29 am
You're to be commended, Belstone, as your ideas sound very intriguing. N-gauge couplings have always been a weak area although Dapol's easi-shunts were a step in the right direction but not without problems. I'll watch your developments with keen interest.

Having undertaken many one-off mods in the past to enable the fitment of Microtrains couplings to a wide range of British stock I have no problems with a kit /unassembled approach.

p.s. I've still not done that mod I promised you feedback on using MT1131 pockets - sorry, I will get round to it if it's still of interest to you.
SF
Title: Re: Coupling survey
Post by: belstone on June 16, 2014, 11:12:13 am
After a bit more thought I'm now leaning towards offering this (if the tests are successful) as a kit with simple fold up etches, square plastic strip for the shank, fold and glue assembly. Only one hole to drill and the etch will give the exact position. The etch design will include a couple of assembly jigs for the tricky bits.  This approach has a couple of advantages: the shank length can be customised for non-standard applications, one kit will cover NEM and T shank, and if I don't use castings or mouldings it will be very, very cheap - possibly down to the magic £1 per pair, sold in a kit of 10 pairs. The way I plan to do this, assembly should be well within the abilities of anyone who can put together a simple plastic kit. Tools required - minidrill and appropriate sized bit, sharp knife, razor saw, wire cutters, needle nose pliers, paint, Superglue and Mek-Pak.  I reckon most modellers should have those already.

I also have in mind a starter kit including a pair of ready assembled and tested (but unpainted) NEM shank couplings, some uncoupling magnets, plus the standard kit. That would probably sell for around £20. Any comments?

Karhedron - thanks very much for your input. Having looked a bit more into 3D printing I don't think it will work as the hook dimensions are absolutely critical - there's some tricky geometry at work here.  I don't think I'll get the strength and accuracy I need with 3D, but I reserve the right to change my mind on that one.

SF - I think the J39 was a one-off. It looks to me as though Farish designed it for T-shanks, then decided to change to NEM pockets after the chassis tooling had been signed off.  Hence that strange little rotating tumbler inside the pocket which I haven't seen on any other NEM equipped loco. You certainly can't convert a 2MT the same way I did the J39.
Title: Re: Coupling survey
Post by: MikeDunn on June 16, 2014, 11:14:38 am
You mentioned some assembly jigs - would they be in each pack, or in the starter pack / sold separately ?
Title: Re: Coupling survey
Post by: belstone on June 16, 2014, 11:26:10 am
You mentioned some assembly jigs - would they be in each pack, or in the starter pack / sold separately ?

I plan to include them within the etch. They are pretty simple things.
Title: Re: Coupling survey
Post by: Howlin`baz on June 16, 2014, 11:48:05 am
One area which I am sure is a concern to most N Gaugers is the unexpected uncoupling.   While you are correct to say that coupling pockets "should be" at the same hight, they are often not.   I am operating a post privitisation stysem using mostly block trains (like manu others who have responded).
It seems to me that there is almost a bigger demand for a bar type coupling to avoid most of the problems.    it would need to be based on a two-part bar with perhaps a ball and socket arrangement in the middle, but NEM fixings at the ends.   Perhaps this would be a good project for 3D printing?
Title: Re: Coupling survey
Post by: SmileyFace on June 16, 2014, 12:03:18 pm
SF - I think the J39 was a one-off. It looks to me as though Farish designed it for T-shanks, then decided to change to NEM pockets after the chassis tooling had been signed off.  Hence that strange little rotating tumbler inside the pocket which I haven't seen on any other NEM equipped loco. You certainly can't convert a 2MT the same way I did the J39.
Ahh that explains it! Actually I've now had a go at that mod and it works perfectly- thanks for the idea. Took 10mins and was tricky to hold the sprung shank in place whilst gluing the cut down MT1131 pocket to the NEM pocket in order to retain the shank. However, it sounds like you've moved on considerably since then. All sounds very exciting!
Title: Re: Coupling survey
Post by: Karhedron on June 16, 2014, 12:06:28 pm
It seems to me that there is almost a bigger demand for a bar type coupling to avoid most of the problems.    it would need to be based on a two-part bar with perhaps a ball and socket arrangement in the middle, but NEM fixings at the ends.   Perhaps this would be a good project for 3D printing?

Something like this perhaps? ;)

http://www.shapeways.com/model/656500/n-scale-nem-fixed-bar-couplings-3-5-5-7mm.html?li=search-results&materialId=25 (http://www.shapeways.com/model/656500/n-scale-nem-fixed-bar-couplings-3-5-5-7mm.html?li=search-results&materialId=25)
Title: Re: Coupling survey
Post by: Howlin`baz on June 16, 2014, 05:07:46 pm
Yes - that looks very good.   Are the pockrts flexible enough to accept the strain of curves?   If so, I will be putting an order in . . .
Title: Re: Coupling survey
Post by: Karhedron on June 16, 2014, 06:57:37 pm
For bogie mounted stock there is no strain as the bogies pivot around the curves. I haven't tried it on fixed wheelbase stock but I can't imagine it having a problem.
Title: Re: Coupling survey
Post by: belstone on June 22, 2014, 02:01:02 pm
Short update: I have spent most of the morning trying to teach myself how to use a CAD program to design coupling hooks.  I'm a slow learner, but now I've got the hang of it I should be able to get a design ready for etching shortly.  Currently having lots of fun plotting the arcs of the moving bits and checking there is enough clearance for it all to work properly.

I'm also getting a better understanding of why the design works so well, which was a bit of a mystery to me when I built the first couple.  It looks like accurate positioning over the uncoupling magnet will be important, and the shorter and more powerful the magnet, the better.  It will be interesting to try it with an under-track electromagnet.

Hoping to have the first test etch done and testing under way in the next couple of weeks - then I'll know whether this is ever going to be a viable product.
Title: Re: Coupling survey
Post by: Caz on June 22, 2014, 04:20:29 pm
More and more intriguing, really looking forward to see what you have come up with.   :)
Title: Re: Coupling survey
Post by: Newportnobby on June 22, 2014, 05:41:02 pm
Me too - sounds like a most exciting development and I hope all goes well during testing :thumbsup:
Title: Re: Coupling survey
Post by: DodgerB on July 21, 2014, 04:27:55 pm
any update?! I'm currently struggling through with starting on MBDs, and can certainly see the potential.

however, it would be a pain fitting each one, and involve a lot of butchering.

Not something I really want to get involved with for new £100+ farish steamers :S

Plus with the flat-plate attachement to the wagon/loco getting each height the same isn't ideal :S.

If your couplers fitted in the standard nem/hole pockets that would be great.
I would personally be happy to glue "filler" bits in the bottom of some pockets if they were the wrong height. I would also be happy to glue it in place - provided no other big butchering was required.
 
A big annoyance with the MBDs is that they decided to put a hole in the middle of the wagon-attachment plate. If they had just left it solid it would give me the option of filing the edge away instead, if it happens to be better to joing it with a long thing piece in the middle.
But you can't join much with a long thin hole!

So if your system had a bit of flexibility in it that would be fab!
Without being so adaptable it looks like a duckbilled platypus of course.
Title: Re: Coupling survey
Post by: belstone on July 21, 2014, 06:23:52 pm
any update?! I'm currently struggling through with starting on MBDs, and can certainly see the potential.


The coupler project has run into a couple of snags.  Firstly, teaching myself CAD via the internet has proved a bit more difficult than I thought. It took me three days to work out how to draw a straight line of a given length. I'm nearly there but still a couple of glitches to sort out in the drawing before it can be turned into an etched fret.

The second snag? Boris.

(http://i753.photobucket.com/albums/xx178/glencoyne/boris_zps7eadf6ad.jpg)

Nearly thirteen years since I last had a puppy and I had forgotten how much time they take up. Hopefully I'll be able to get the drawing finished this week, after that things should start moving again.

Richard
Title: Re: Coupling survey
Post by: Jerry Howlett on July 30, 2014, 09:21:43 am
Thats a "play with me daddy" face, chap or chappess ?

Jerry
Title: Re: Coupling survey
Post by: belstone on August 04, 2014, 10:30:26 am
First test etches arrived this morning and look exactly like what I thought I had drawn on the computer which is a promising start.  If the basset puppy gives me a few minutes of peace this evening I'll try building up a few couplings and see what happens. He woke me up at 1.30am in the hope of playing some biting games.
Title: Re: Coupling survey
Post by: Caz on August 04, 2014, 01:54:24 pm
The suspense is killing, dying to see what you've come up with.   :)
Title: Re: Coupling survey
Post by: belstone on August 11, 2014, 10:02:17 am
Progress report....

Yesterday I finally got round to building up a handful of couplers and fitting them to vehicles.  They go together pretty much exactly as I hoped and the NEM-pattern ones clip into the coupler boxes with a little bit of fettling.  I'm getting down to around 15 minutes per pair to build, fit and adjust. Then the problems started.

I only had one loco with unmodified NEM pockets, a Farish Ivatt 2MT which I hadn't run for any length of time.  It turned out to have pickup issues making slow speed control impossible. I also had problems with the couplers failing to uncouple reliably which I am still working on.  The length and angle of the drop arm are critical as is the length of the under-track bar magnet, which needs to be very short so that it pulls the drop arms towards each other with the vehicles positioned centrally over the magnet.  And I screwed up the dimensions of the bar bending jig on the etched fret but that is easy enough to fix. I also had problems with the coupler bars getting snarled up with each other, but I think I have a simple fix for that.

I'm now building up a few more couplers so I can fit them to one of my reliable locos (a J39) and a couple of coaches. I also need to play around with magnets of various kinds - under track magnets are all very well, but not so good if you have already laid and ballasted your track. I bought a Peco electromagnetic uncoupler but it doesn't seem very powerful. I don't seem to have had much luck so far finding a supplier of magnets in various sizes at a sensible price - I am using B&Q cupboard catch magnets cut in half at the moment but I really need something that fits between the rails and sits level with the top of the sleepers.

I didn't have my camera with me at home so no photos yet, but I'll try to take a few this evening. Some of you may be disappointed when I do - there is nothing exotic or sophisticated about this coupler, it is just a boring old tension-lock with a fixed hook, Sprat and Winkle style delay post and a single-sided lifting loop operated by a dropper arm with a bit of steel tube stuck on the end.  The phrase "tension-lock" will probably put off about half of you but they are going to be pretty inexpensive - target price is £15 for 10 pairs. I know the B&B / DG couplers are a lot cheaper than that, but ever tried assembling one? Watchmaking is easy in comparison.

More to follow when I have some pictures.
Title: Re: Coupling survey
Post by: Malc on August 11, 2014, 10:08:47 am
If you want a small powerful magnet, try a rare earth one .ie http://www.ebay.co.uk/itm/20-x-Strong-Round-Magnet-5mm-x-2mm-Disc-Rare-Earth-Neodymium-N35-Grade-/370846166861?pt=LH_DefaultDomain_3&hash=item5658276f4d (http://www.ebay.co.uk/itm/20-x-Strong-Round-Magnet-5mm-x-2mm-Disc-Rare-Earth-Neodymium-N35-Grade-/370846166861?pt=LH_DefaultDomain_3&hash=item5658276f4d)
Title: Re: Coupling survey
Post by: belstone on August 11, 2014, 10:41:48 am
If you want a small powerful magnet, try a rare earth one .ie [url]http://www.ebay.co.uk/itm/20-x-Strong-Round-Magnet-5mm-x-2mm-Disc-Rare-Earth-Neodymium-N35-Grade-/370846166861?pt=LH_DefaultDomain_3&hash=item5658276f4d[/url] ([url]http://www.ebay.co.uk/itm/20-x-Strong-Round-Magnet-5mm-x-2mm-Disc-Rare-Earth-Neodymium-N35-Grade-/370846166861?pt=LH_DefaultDomain_3&hash=item5658276f4d[/url])


Thanks for that. I quickly found a UK supplier and have now ordered disc and bar magnets in several sizes. 
Title: Re: Coupling survey
Post by: belstone on August 12, 2014, 11:12:57 am
As promised a few photos.  Please remember this is still very much a work in progress and I am a fair way off being able to say whether this is a viable design, but a lot of you have been very helpful with your input and views and it seems only fair that I should keep everyone up to date.

(http://i753.photobucket.com/albums/xx178/glencoyne/coupler4_zps5d90a141.jpg)

Raw materials - the etched fret, some plastic strip, copper jewellery pins and a handful of hooks bent up and attached to shanks.  The fixed plastic shank makes them easy to fit whether you have Rapido pockets, NEM pockets or (scratch and kit built vehicles) no pockets at all.

(http://i753.photobucket.com/albums/xx178/glencoyne/coupler1_zpsc9d3c9e3.jpg)

Completed (but unpainted) NEM clip-fit coupler, cruelly enlarged. The bar on this one is the wrong shape - I have since added a short bend at the end to stop the bars getting tangled up.

(http://i753.photobucket.com/albums/xx178/glencoyne/coupler3_zps9495ea31.jpg)

(http://i753.photobucket.com/albums/xx178/glencoyne/coupler2_zpsbaff16e5.jpg)

Coupler fitted to a Farish horsebox.  You'll have to take my word that it looks less ugly and obtrusive in reality than in the photos. Any N gauge coupler is going to be a compromise between appearance, reliability and ease of assembly/fitting.  This particular design is very much biased towards operation at the expense of appearance - which is what the survey suggested most people wanted. I'm going to look into having the etches chemically blackened which should help. I might also rework the design a little and slim down the delay bar - it doesn't need to be as thick as it is. And I think I'll have to redesign the hook slightly to reduce the risk of self-uncoupling over the magnets - it isn't quite 'hooky' enough on this first version.  Good thing I only had two frets made...

Magnets should be here tomorrow - then I can start to play properly on a real layout.
Title: Re: Coupling survey
Post by: Caz on August 12, 2014, 02:24:41 pm
Interesting, looking forward to seeing the live tests and how well the delayed action works.   :thumbsup:
Title: Re: Coupling survey
Post by: belstone on August 12, 2014, 06:34:11 pm
(http://i753.photobucket.com/albums/xx178/glencoyne/coupler5_zps360875eb.jpg)

T-shank variant, fitted to a couple of older Farish coaches.

(http://i753.photobucket.com/albums/xx178/glencoyne/coupler6_zps6185dfc4.jpg)

Popped straight in, with a sliver of plastic at the back to hold them in place.  I had to shave a bit off the corner of the pocket to clear the drop arm - Farish Rapido pockets are quite wide. But the original couplers can still be refitted if required.

I think clearance between the buffers is going to be very tight on Setrack curves, but 12 inch radius should be fine. I've also fitted a coupler to one end of a J39, so off home now to have a play.
Title: Re: Coupling survey
Post by: belstone on August 15, 2014, 02:21:54 pm
A word of advice: if anyone else out there is thinking of designing an N gauge coupling, get hold of a plank of wood. Then hit yourself over the head repeatedly, until the thought goes away.   :D

I have run into a couple (ho ho) of problems.  The first is easy to fix: I got the dimensions wrong on the fold-up channel which attaches the hook to the shank. So I had to file down the shank on three sides, and that makes it too weak to stand up to rough handling. I now have a small pile of broken couplings.

The second is trickier. It's the same problem I ran into with the Micro Trains knuckle couplers: light, free-rolling four-wheeled vehicles tend to be pulled towards the magnet by the drop arm, slackening the tension on the coupling just as it passes over the magnet and causing the last wagon in the train to uncouple.  I tried extending the end of the hook backwards with a small piece of wire which helps (and I can incorporate this into the etch) but doesn't entirely solve the problem. I have a couple of other ideas to try, otherwise I will have to resort to increasing the rolling resistance of my wagons which isn't really ideal.

It doesn't help that the neodymium magnets I bought are very powerful, possibly a little too powerful when fitted between the rails. On the plus side, this means the delayed uncoupling feature works 100%. I'll carry on fiddling over the weekend. I'm still finding out which dimensions are critical and which are less important. Slight height mismatch isn't an issue, but the distance from the front of the loop to the pivot point has to be spot on, likewise the shape of the magnetic drop arm.

It might be that electromagnets are the way forward, but I bought a Peco PL-10 uncoupler and it isn't nearly powerful enough: with it energised, the drop arm has to be practically touching the end of the uncoupler before it moves.
Title: Re: Coupling survey
Post by: Caz on August 15, 2014, 02:32:52 pm
Have you tried either the Dapol or Microtrains bar magnets, maybe being slightly less powerful it may work better.  Keep trying, I'm sure you'll crack it in the end, either that or your head if you keep hitting yourself on the head like that.   :)
Title: Re: Coupling survey
Post by: PostModN66 on August 15, 2014, 03:34:00 pm

It might be that electromagnets are the way forward, but I bought a Peco PL-10 uncoupler and it isn't nearly powerful enough: with it energised, the drop arm has to be practically touching the end of the uncoupler before it moves.

You might consider vertically sliding magnets rather than electro-magnets.  I use this approach on "Lofthole" and it works very reliably, and is easy to set up.   Note: this is just for modified Rapidos, nothing fancy like delayed action, but the principle should still apply.

https://www.youtube.com/watch?v=S_IF-CPyeI0 (https://www.youtube.com/watch?v=S_IF-CPyeI0) illustrates.

Cheers

Jon  :)
Title: Re: Coupling survey
Post by: Dock Shunter on August 15, 2014, 10:03:39 pm

It might be that electromagnets are the way forward, but I bought a Peco PL-10 uncoupler and it isn't nearly powerful enough: with it energised, the drop arm has to be practically touching the end of the uncoupler before it moves.



If you plan to use electromagnets then i would recommend either Gaugemater EM 1s
or the DG electromagnets.
They are not cheap but do the job.

 :beers:.....Ste...... :NGaugersRule:
Title: Re: Coupling survey
Post by: kardkits on August 15, 2014, 10:59:25 pm

You might consider vertically sliding magnets rather than electro-magnets.  I use this approach on "Lofthole" and it works very reliably, and is easy to set up.   Note: this is just for modified Rapidos, nothing fancy like delayed action, but the principle should still apply.

Cheers

Jon  :)

I like the look of that Jon, where can I get more information about these?

Thanks
Andi
Title: Re: Coupling survey
Post by: PostModN66 on August 17, 2014, 02:17:47 pm
These (rather dull, sorry) shots should illustrate:
(http://www.ngaugeforum.co.uk/SMFN/gallery/53/thumb_8776.JPG) (http://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view;id=8776)
(http://www.ngaugeforum.co.uk/SMFN/gallery/42/thumb_14920.jpg) (http://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view;id=14920)
(http://www.ngaugeforum.co.uk/SMFN/gallery/42/thumb_14921.jpg) (http://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view;id=14921)
(http://www.ngaugeforum.co.uk/SMFN/gallery/42/thumb_14922.jpg) (http://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view;id=14922)
(http://www.ngaugeforum.co.uk/SMFN/gallery/42/thumb_14923.jpg) (http://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view;id=14923)

It.s worth saying that I have only so far used this system on Kato Unitrack.  If using it on Peco track I would do a test to see if the magnets coming up to the bottom of the sleepers would provide enough flux, or whether you would need to use smaller magnets to come up between the sleepers, to say, level with the sleeper tops.

Ask if you need any more,

Cheers

Jon
Title: Re: Coupling survey
Post by: GavinD on August 17, 2014, 04:03:09 pm

It's worth saying that I have only so far used this system on Kato Unitrack.  If using it on Peco track I would do a test to see if the magnets coming up to the bottom of the sleepers would provide enough flux, or whether you would need to use smaller magnets to come up between the sleepers, to say, level with the sleeper tops.

Hi John

Excellent idea this. I am just wondering how to "switch" on/off  a niobium disc magnet on the hidden sidings of a small shunting puzzle layout that I have just about completed. On one siding ( near rear edge ) I managed to excavate a channel to allow a magnet to be buried in a plasti-card holder so it can be manually slid from under the track. But also want to do the same on a parallel line behind it, so drilling a hole through base will be easier than trying to excavate a longer channel. My alternate was to cut out a section of both tracks and fit two slides. So I will give this a try.

I have fitted modified DG couplings to all my wagons now - loop one end - hook the other - as I don't mind them being uni-directional  :D  and they are very reliable this way, and unobtrusive.
The magnets work fine on these with the top of the niobium disc magnet level with the underside of the Peco 55 track.

Apart from only fitting hook/loop to one end only I have developed a variation on the actuating dropper by combining it as an extension of the loop and fitting wrapping some soft iron wire around a horizontal bend at the end of the dropper. I find this makes assembly much easier, as no need to solder the dropper to the loop { I could never get the two materials to bond  :( } and also easier to fit to the fret.
If anyone is interested I could take a few macro photos and do a diagram.

Cheers
    Gavin
Title: Re: Coupling survey
Post by: Newportnobby on August 17, 2014, 04:27:06 pm

The magnets work fine on these with the top of the niobium disc magnet level with the underside of the Peco 55 track.


Sorry to be a bit thick, Gavin, but when you say the 'underside' of the track do you mean above sleeper height but level with the base of the rail, or level with the base of the sleeper? Thanks.
Title: Re: Coupling survey
Post by: GavinD on August 17, 2014, 04:41:36 pm

The magnets work fine on these with the top of the niobium disc magnet level with the underside of the Peco 55 track.


Sorry to be a bit thick, Gavin, but when you say the 'underside' of the track do you mean above sleeper height but level with the base of the rail, or level with the base of the sleeper? Thanks.

Sorry! should have made myself clearer;
 Top of disc magnet ( 5mm diam x 3mm thick ) level with underside of sleeper.
Cheers
 Gavin
Title: Re: Coupling survey
Post by: belstone on August 18, 2014, 01:03:43 pm
Neodymium magnets are starting to look a bit like a dead end.  They don't just attract the dropper bars on the couplings, but also the steel weights in Peco wagons... Next stage is to get some Mk2 test etches (reshaped hook, deeper side members where the hook attaches to the shank) and some conventional ferrite magnets, then have another go.  The Dapol and MT magnets are polarised to pull sideways, not down, so they will probably not work with this design. I briefly tried an MT magnet but it didn't work very well. I'm not disheartened yet, but glad I'm not relying on this project to pay the household bills.

Incidentally I also tried a couple of neodymium bar magnets on the outside of the rails to see if they would operate the MT couplers (and Dapol which uses the same basic principle).  They worked all right: they pulled the entire wagon sideways off the rails....
Title: Re: Coupling survey
Post by: ScottyStitch on August 18, 2014, 02:39:25 pm
  The Dapol and MT magnets are polarised to pull sideways, not down, so they will probably not work with this design.

Try putting them on their side.....?
Title: Re: Coupling survey
Post by: GavinD on August 18, 2014, 03:11:10 pm
Neodymium magnets are starting to look a bit like a dead end.  They don't just attract the dropper bars on the couplings, but also the steel weights in Peco wagons...

Hi Jon

Any magnet will do this!  I have taken out the steel weights and replaced with lead - problem solved.
But wash your hands well and KEEP the magnets away from children and animals; there have been cases of them being swallowed and clumping together in the stomach  - nasty  :o

Cheers
    Gavin
Title: Re: Coupling survey
Post by: PostModN66 on August 18, 2014, 03:44:36 pm
Neodymium magnets are starting to look a bit like a dead end.  They don't just attract the dropper bars on the couplings, but also the steel weights in Peco wagons...

Hmmm....I haven't noticed this issue with my set up.....maybe because I don't use many Peco wagons, (although my TEAs are weighted with big steel nails) but in my "Lofthole Part 1" video the lead wagon on the ballast train is a Peco wagon with standard weight..

see 1:40  https://www.youtube.com/watch?v=lRa9gqsSMp4 (https://www.youtube.com/watch?v=lRa9gqsSMp4)

Is there a problem when you bring the magnet to a static wagon...or is it just when a wagon is moved across the magnet?

Cheers Jon  :)
Title: Re: Coupling survey
Post by: N Gauge Bob on August 18, 2014, 04:32:45 pm

It's worth saying that I have only so far used this system on Kato Unitrack.  If using it on Peco track I would do a test to see if the magnets coming up to the bottom of the sleepers would provide enough flux, or whether you would need to use smaller magnets to come up between the sleepers, to say, level with the sleeper tops.

Hi John

Excellent idea this. I am just wondering how to "switch" on/off  a niobium disc magnet on the hidden sidings of a small shunting puzzle layout that I have just about completed. On one siding ( near rear edge ) I managed to excavate a channel to allow a magnet to be buried in a plasti-card holder so it can be manually slid from under the track. But also want to do the same on a parallel line behind it, so drilling a hole through base will be easier than trying to excavate a longer channel. My alternate was to cut out a section of both tracks and fit two slides. So I will give this a try.

I have fitted modified DG couplings to all my wagons now - loop one end - hook the other - as I don't mind them being uni-directional  :D  and they are very reliable this way, and unobtrusive.
The magnets work fine on these with the top of the niobium disc magnet level with the underside of the Peco 55 track.

Apart from only fitting hook/loop to one end only I have developed a variation on the actuating dropper by combining it as an extension of the loop and fitting wrapping some soft iron wire around a horizontal bend at the end of the dropper. I find this makes assembly much easier, as no need to solder the dropper to the loop { I could never get the two materials to bond  :( } and also easier to fit to the fret.
If anyone is interested I could take a few macro photos and do a diagram.

Cheers
    Gavin

I took my lead from the N Gauge Society book where a chap had made the whole loop and dropper from one piece of iron wire...works fine for me but I still have 350 of my 800 odd wagons to do. (I use long and short modified rapidos for carriages with decent size bellows and the cuncoupliong pip removed).

On the new layout I have to consider wagons being reversed so I have to retrospectively fit loops to both ends, but damned if I can get them to work properly.

Just a tip for those with DGs who store in foam trays...cut a small piece of card and insert in the ends of each compartment...stops them snagging.

Cheers
Bob
Title: Re: Coupling survey
Post by: belstone on August 21, 2014, 11:58:35 am

Hmmm....I haven't noticed this issue with my set up.....maybe because I don't use many Peco wagons, (although my TEAs are weighted with big steel nails) but in my "Lofthole Part 1" video the lead wagon on the ballast train is a Peco wagon with standard weight..

see 1:40  https://www.youtube.com/watch?v=lRa9gqsSMp4 (https://www.youtube.com/watch?v=lRa9gqsSMp4)

Is there a problem when you bring the magnet to a static wagon...or is it just when a wagon is moved across the magnet?

Cheers Jon  :)

The problem is when the wagon is moved across the magnet.  As soon as the steel weight is within range of the magnetic field it pulls the wagon forward.  I now have some ferrite magnets to play with - a lot less powerful, but will still attract a Peco wagon weight when fitted between the rails.  An under-track magnet might be OK, but I don't want to end up with a coupling system that needs me to dig up my ballasted and painted track to install it.

I don't know if anyone other than Peco uses steel weights. Their wagons are a bit on the light side anyway, and some thin lead strip in place of the steel might not be a bad idea.  Steel axles and wheels (e.g. older Farish, Parkside-Dundas) will cause the same problem.

Anyway, Mk2 coupling etches are now on order and I'll see if they work better than the first design.  It is a bit frustrating - these couplings are easy to make and fit, they work perfectly on larger, heavier vehicles but the reliability on short wheelbase wagons just isn't good enough at the moment, and the need to shunt such wagons on my layout is the whole reason I started developing a new coupler design in the first place.

Richard
Title: Re: Coupling survey
Post by: Rabs on August 21, 2014, 01:39:12 pm
Steel axles and wheels (e.g. older Farish, Parkside-Dundas) will cause the same problem.

Unfortunately I don't think that it's just older wheels - the Farish wagon wheelsets I bought a few weeks ago have steel axles.
Title: Re: Coupling survey
Post by: PostModN66 on August 21, 2014, 06:55:44 pm
With careful work you could use my system without digging up the track - drill a small pilot hole between the sleepers, then very carefully drill upwards with a larger drill to make a hole to install the tube, stopping when you get to the bottom of the sleepers!

Cheers Jon  :)



Title: Re: Coupling survey
Post by: belstone on August 22, 2014, 09:22:41 am

Unfortunately I don't think that it's just older wheels - the Farish wagon wheelsets I bought a few weeks ago have steel axles.

I hadn't noticed any problems with the Farish vehicles I was testing but you are right, they have steel axles.  I tried a cattle van with the couplings removed and there is a slight tendency to be pulled towards the centre of the magnet, but I don't think it is strong enough to be a problem, unlike the Peco wagons.
Title: Re: Coupling survey
Post by: belstone on August 22, 2014, 09:26:25 am
With careful work you could use my system without digging up the track - drill a small pilot hole between the sleepers, then very carefully drill upwards with a larger drill to make a hole to install the tube, stopping when you get to the bottom of the sleepers!

Cheers Jon  :)

I like your system a lot, but I want to keep experimenting with fixed magnets for now due to their sheer simplicity. By the end of next week I should be a bit further forward with the testing - aiming to equip two locos and about a dozen assorted coaches and wagons once the new etches arrive.
Title: Re: Coupling survey
Post by: belstone on September 03, 2014, 10:31:48 pm
Edging towards a successful coupling design... The Mk 2 couplings are a lot more robust than the first version and less prone to self uncoupling. Short wheelbase wagons, even lightweight Peco ones, work fine provided there is no steel content.  That includes wheelsets, ballast weights, the nuts that Peco use to secure the body to the chassis and even the steel bracing wires on Peco 10' tank wagons. Peco nylon wheelsets will fit Farish wagons but need the axleboxes drilling out as the Peco axles are longer than the Farish ones.

I am now confident enough to have dug up all the Microtrains magnets on my layout and replaced them with small neodymium bar magnets which sit about level with the top of the sleepers.  After experimenting with increasingly ornate and hard to bend bar designs I have found that a simple 'U' shape works best. Why didn't I try that at the start? Having ordered some 'copper' pins that turned out to be plated steel I tried using them to make the loops.  I won't be doing that again. The loops have to be non-magnetic.

A few issues still to overcome, not least that my layout has taken offence at being ignored for three months and developed a whole bundle of running problems, much finger poking required to get any of my locos to run. So it is a bit hard to assess reliability of the couplings until I sort that out.  I'm probably getting about 90% reliability in coupling, 75% in uncoupling and delayed uncoupling. Not good enough but I'm working on it.

I also have a problem on some vehicles with the loop dropping over the back of the delay bar and locking vehicles together.  Looks like I might need to fit a buffer pad under the coupling shank, still trying to work out the best way to build that into the etch.

And sadly it looks like all my Parkwood kit built wagons are scrap.  They have steel weights, and the Peco chassis are firmly Superglued to the bodies and won't separate whatever I try.

Title: Re: Coupling survey
Post by: belstone on September 03, 2014, 11:38:27 pm
A short video showing the couplings in operation - jerky hesitant running and all.  For the cynics among you - this was the first take.

http://youtu.be/pIofK1GQNGM (http://youtu.be/pIofK1GQNGM)
Title: Re: Coupling survey
Post by: Caz on September 04, 2014, 08:15:50 am
Regrettably that's me out of this coupling as I converted all my plastic wheel stock to metal wheels to get rid of the horrible crud that nylon wheels generate on the the track.  I also need metal wheels as I use them for pickups for track detection and to power things light coach and guards van lights etc :sorrysign:
Title: Re: Coupling survey
Post by: Rabs on September 04, 2014, 08:18:58 am
Regrettably that's me out of this coupling as I converted all my plastic wheel stock to metal wheels to get rid of the horrible crud that nylon wheels generate on the the track.  I also need metal wheels as I use them for pickups for track detection and to power things light coach and guards van lights etc :sorrysign:

Sadly I'm in the same boat.  Using metal wheels is more important to me than having better couplings.
Title: Re: Coupling survey
Post by: talisman56 on September 04, 2014, 08:52:40 am
A short video showing the couplings in operation - jerky hesitant running and all.  For the cynics among you - this was the first take.

[url]http://youtu.be/pIofK1GQNGM[/url] ([url]http://youtu.be/pIofK1GQNGM[/url])


Looking good - as one becomes used to operating them, the short trip backwards to uncouple before shunting forward will become an imperceptable movement...
Title: Re: Coupling survey
Post by: Newportnobby on September 04, 2014, 10:05:35 am
For a first take it looks pretty damned good :thumbsup:
Title: Re: Coupling survey
Post by: NeilWhite on September 04, 2014, 10:09:11 am

Hi

There are a couple of things from MicroTrains that can be useful for other types of delayed uncouplers.

On the subject of uncoupler magnets, on my shunting plank layout I use MicroTrains couplers, and use their under-track magnets in a set up something like that displayed here: http://whiteriverandnorthern.net/clinic_30.htm (http://whiteriverandnorthern.net/clinic_30.htm)
It's a bit 'Heath Robinson', but it is easy to set up and does work, and deals with the uncoupling-at-the-wrong-time issue effectively.

Also MicroTrains sell little springs that you put on the end of one or two axles (i.e. between the wheel and the wagon frame) which help with the wagon being pulled toward the uncoupler magnet. They don't seem to add a lot of drag in normal running.  A lot of the wagons on my shunting plank are Peco, and I've replaced the steel weights with other material - brass, lead, or the tungsten putty that fishermen use these days use instead of lead. I think the springs are included in some of the Microtrains coupler packets and were once (I haven't bought any of this stuff for a while) available separately as well.

Neil


 
Title: Re: Coupling survey
Post by: belstone on September 04, 2014, 11:53:35 am
Regrettably that's me out of this coupling as I converted all my plastic wheel stock to metal wheels to get rid of the horrible crud that nylon wheels generate on the the track.  I also need metal wheels as I use them for pickups for track detection and to power things light coach and guards van lights etc :sorrysign:

I'd rather have metal wheels myself. I'm wondering how much it would cost to have replacement axles for Farish wheelsets made in brass or stainless. Always assuming the wheels come off the old axles easily enough of course.  Could be done in two lengths, Farish axles being a bit shorter than Peco. A CNC lathe could probably knock them out by the thousand - maybe even with a step to ensure accurate back to back and axle centring without needing a gauge.
Title: Re: Coupling survey
Post by: belstone on September 04, 2014, 10:59:32 pm
I might have been wrong about Farish steel axles.  As an experiment I just fitted the couplings to a Farish cattle van. I replaced the steel ballast weight with lead but kept the Farish metal wheels.  It works fine, no tendency to self-uncouple or otherwise misbehave. No different to my other cattle van which has Peco plastic wheels. I've noticed the current Farish wagons don't seem as free-running as the old Peco ones, which helps when you are using permanent magnets.

Now I just need to buy a few more new Farish wagons to replace my Parkwood/Peco ones, and see if the cattle van was just a fluke. And do something about the loops over-riding the delay bars, which I've found is a much bigger problem with NEM side-sprung coupler pockets than fixed ones. I know why it is happening, just need a neat, simple fix for it.

Richard
Title: Re: Coupling survey
Post by: Newportnobby on September 05, 2014, 10:00:23 am
The work you are putting into this is much appreciated, Richard.
OK, it's mainly for your own reward but potentially many of us could gain from it so......
 :thankyousign:
Title: Re: Coupling survey
Post by: belstone on September 05, 2014, 10:20:03 pm
The work you are putting into this is much appreciated, Richard.
OK, it's mainly for your own reward but potentially many of us could gain from it so......
 :thankyousign:


Not much reward I fear, apart from ending up with a coupler system that suits my particular obsession with steam-era branch lines.  I hate to think how many hours I have put into this now - I'd have to sell an awful lot of couplings to make it financially worthwhile. But this is just the sort of design and development challenge that I enjoy for its own sake.  Over the weekend I will try to build a few 'Mk2B' couplings with redesigned delay bar - a bit fiddly as I will have to solder brass wire to the hooks while they are still attached to the fret. Mk3 will be a one piece etching if I get that far.

One small development - I have been wondering how best to paint the couplings. I decided to try black permanent marker - 'borrowed' from the kitchen where it is normally used to mark the contents of freezer bags.  Result is not too shabby, and unlike paint it doesn't gum up the works:

(http://i753.photobucket.com/albums/xx178/glencoyne/030914002_zps0a60916c.jpg)
Title: Re: Coupling survey
Post by: Jerry Howlett on September 07, 2014, 11:23:30 am
If it was me the hillside around here would be covered in small pieces of plastic and metal crushed and scattered to the wind.

I know I am not alone in watching your progress on this with a bag full of hope that it all comes together (or apart) over the magnet  :sorrysign:  in the end.

Keep up the good work and the progress reports.

Jerry
Title: Re: Coupling survey
Post by: belstone on September 07, 2014, 09:54:15 pm
Another weekend of fiddling has seen the design progress rapidly through Mk2B (short piece of bent piano wire glued to the shank to stop the loop dropping over the end of the delay bar) to Mk2C (longer loop with bent up end, as per the Mk1 to stop the ends of the loops locking together). I now have enough converted vehicles to start proper testing, but my past sins have caught up with me.

Some of the trackwork on 'Belstone' really is terrible.  I laid it in a tearing hurry, ballasted it in even more of a hurry and I now have wonky bits of track and stray ballast grains which always seem to cause the loco to stall just as the last wagon in the train passes over the magnet.

I have also found that coupling height is more important than I thought - you can get away with about 0.5mm mismatch but more than that and delayed uncoupling becomes a bit hit and miss. Of course if I had fitted the couplings properly there wouldn't be a height mismatch...

And I now really, really hate NEM pockets.  I have seen jellies that wobble less than a Farish NEM pocket insert.

Richard

Title: Re: Coupling survey
Post by: belstone on September 20, 2014, 08:43:35 am
Slow progress due to family illness and work stuff, but I'm now onto Mk2D (end of loop bent up and back rather than up and forwards) and finally getting reasonable results with Peco short wheelbase wagons which were always going to be the hardest vehicles to get any kind of uncoupling system to work with, since they are so small, light and free-rolling. 

I spoke to my father about the problem.  He was modelling in N gauge before I was born (I'm 46) and has a very practical mind. "File the pinpoints off the axle ends" he said.  So I did, and now have just enough rolling resistance to allow reliable operation...

One other discovery - the metal used in Bachmann-Farish wagon axles varies.  Some of them are strongly attracted to magnets, others aren't.  I haven't yet worked out whether it is the newer axles that are non-magnetic or the older ones.
Title: Re: Coupling survey
Post by: belstone on September 29, 2014, 09:53:20 am
Another weekend of fiddling and fettling, and I'm almost there.  I now have two locos, two coaches and ten wagons fitted with Mk2d couplings, and have reached the stage where if a coupling fails to work properly I can look at it, identify the reason and fix it.  I can now perform complex shunting operations. I even managed to get my J39 to run half decently by packing some extra weight into the boiler.

If a coupling doesn't work reliably it is usually down to incorrect height, magnetic dropper not bent back far enough, coupling bar slightly twisted, or the bar being slightly too long and fouling a buffer head.  All easily fixable.

So I have pretty much done what I set out to do - develop a simple, robust and cheap coupling system, suitable for steam-era branch terminus layouts and short wheelbase wagons, which uses cheap, unobtrusive permanent magnets between the rails and can be fitted to pretty much any RTR loco, coach or wagon without having to butcher the coupler pockets.  I've noticed that compared to 4mm there are very few branch terminus layouts in 'N' and I would guess that is because, without reliable slow running and a decent coupler system, a branch terminus is never going to be very satisfying to operate.

My design won't suit everyone.  I think sharp curves and especially reverse curves could be a problem: my layout uses Peco medium radius points which are fine, but I haven't yet tested the system on anything tighter.  Like any DIY coupler system, assembly and fitting takes time, and you need fairly steady hands and good eyesight. Having said which, compared to assembling B&B or DG couplers these are a walk in the park.  Replacing steel wagon weights with non-magnetic ones is essential, and older Farish wheelsets with mild steel axles will need changing.

Light, free-rolling vehicles have also given me a few problems with the last vehicle in a train self-uncoupling over the magnets.  Weighting wagons helps a lot: I have also tried slipping a small coil spring over the end of one axle on a Farish horsebox (like the 'truck restraining springs' that Micro-Trains supply to fix the same problem) and that worked well.  The vehicle still rolls freely enough, but the spring gives just enough drag to stop it being pulled forward by the coupler drop arm as it approaches the magnet. 

I tried making a short video of the couplings in operation and found that the only time they don't work reliably (after a fairly long operating session with everything working fine) is when there is a camcorder pointed at them. And then one of the couplings fell off my J39 (defective gluing) and ended the filming session.  I'll try to fix that and have another go.

Next stage is to write up some detailed instructions and get some more frets etched up.  After that I will be looking for couple of volunteers to try them out and see if they can get them to work following the instructions.  If anyone fancies having a go, let me know.

One other thing - I found that Farish wagons with clip on coupler pockets are incredibly easy to convert.  Just unclip the pockets, drill a small hole in the floor and attach the coupler with a small brass screw through the shank. Good news for steam or transition era branch line modellers as the Farish range covers just about every wagon type you might need.
Title: Re: Coupling survey
Post by: belstone on October 01, 2014, 09:48:03 am
I fitted a new front coupler to the J39 and had another go at filming.  Here it is.

https://www.youtube.com/watch?v=kRXK8v2w0iE (https://www.youtube.com/watch?v=kRXK8v2w0iE)

The J39 still isn't running too well, but only one intervention from the 'Hand of God'.  And I need to look at that Conflat, one of the couplers is playing up. But you get the general idea.

It occurred to me that for locos, unless you need double-heading, a plain hook without the lifting bar should work OK and be a lot easier to fit.  There are some locos (older Farish diesels for example) where there isn't enough room for the magnetic drop arm.  So I put a plain hook on the front of the J39 and as you can see it works fine.

Another potential problem is on locos with long end overhangs and no bogie or pony truck - like the J39.  I found that I had to bend the hook outwards slightly to avoid the couplers binding and causing derailments when propelling wagons around curves.  Shouldn't be a problem with  most diesels as the couplers are mounted on the bogies, but I've bought a Farish '08' for trials, as it combines a short fixed wheelbase with long overhangs both ends. If anything is going to give serious problems, that will.
Title: Re: Coupling survey
Post by: Newportnobby on October 01, 2014, 10:03:04 am
Fascinating bit of shunting there :thumbsup:
Assuming the 'shiny rectangles' to be the Dapol magnets, you seem to have cracked the delayed release of uncoupled trucks (or you have other magnets very well disguised). The static camera does not portray this sufficiently, I fear :hmmm:
On a scale of 1-10 with 1 being the most unhappy, how happy are you with what you have achieved please?
It all looks rather good :claphappy:
Title: Re: Coupling survey
Post by: belstone on October 01, 2014, 10:08:08 am
I'm still acquiring vehicles from different manufacturers for development purposes.  Today's post brought my first two Dapol products - a new 21 ton hopper, and an older gunpowder van.  Looking good - both have non-magnetic wheelsets (although of two different types) and straightforward spring-loaded T-shank Rapidos in sensibly sized pockets. The van has a steel weight which is easy enough to replace: the hopper has no steel content at all. Happy days.
Title: Re: Coupling survey
Post by: belstone on October 01, 2014, 10:18:15 am
Fascinating bit of shunting there :thumbsup:
Assuming the 'shiny rectangles' to be the Dapol magnets, you seem to have cracked the delayed release of uncoupled trucks (or you have other magnets very well disguised). The static camera does not portray this sufficiently, I fear :hmmm:
On a scale of 1-10 with 1 being the most unhappy, how happy are you with what you have achieved please?
It all looks rather good :claphappy:

The rectangles are neodymium bar magnets 20 x 5 x 2mm, about flush with the top of the sleepers. Cheap, easy to install and effective. I need to repair the damaged ballast around them and then paint them at which point they should look a lot less obvious.

How happy am I? Ecstatic. Call it 11 on a scale from 1 to 10.  I have a coupler system which is cheap, mostly reliable, not too hard to make and fit and does exactly what I want it to do. And all through fiddling around with brass, plastic and wire in the spare bedroom. It's taken a long time to get there, and there are still some potential issues (mainly around propelling short wheelbase wagons on sharp curves), but hopefully a few people will adopt this system and we will see some more branch terminus and goods yard layouts in N gauge.
Title: Re: Coupling survey
Post by: belstone on October 04, 2014, 01:04:46 pm
Have Farish given up trying to make standard N gauge couplers work? The '08' I just bought has the worst implementation I have yet seen of a Rapido type coupler in an NEM pocket.  The plastic centring 'springs' in the pocket insert are too weak so the coupler flops from side to side, and there is barely any vertical movement at all.  Easy to convert though - I just popped the insert out of the pocket, built up the plastic shank on the new coupler with thin Plastikard so it was a snug fit in the pocket and secured it with a small screw. Easy and fully reversible if I want to sell the loco later on.

I'm rapidly running out of prototype etched hooks so I'm now working on the definitive 'Mk3' etch design, along with some 3D printed NEM pattern shanks which will save a bit of drilling and filing. Also thinking about a small shunting layout for demonstration purposes. 

Richard
Title: Re: Coupling survey
Post by: belstone on October 06, 2014, 07:47:10 am
(http://i753.photobucket.com/albums/xx178/glencoyne/051014002_zps7ef8dae0.jpg)

This is starting to look like the optimum shape for the coupler loop - ends bent up and back.  I tried this on four wagons and it works very well, and seems happy on the short radius points in the fiddle yard as well.

(http://i753.photobucket.com/albums/xx178/glencoyne/051014004_zps71f0ea6e.jpg)

The coupler R&D department now has its very own test locomotive.  Ebay bargain, perfect and apparently never been used, for £48.
Title: Re: Coupling survey
Post by: Bealman on October 06, 2014, 08:04:59 am
Great updates. Thanks for posting!  :thumbsup:
Title: Re: Coupling survey
Post by: belstone on October 06, 2014, 10:16:29 am
Looking at that second photo - you'd be hard pressed to say whether that was N or OO I reckon. Sometimes we forget how lucky we are with the quality of the newer Farish stuff.

On the way into work I was thinking about bending up coupler loops which is a bit fiddly.  I now have an idea in my head for a simple jig which will ensure the loops are consistently the same shape. I'll knock up a prototype and then see how much it will cost to get some machined up, or possibly 3D printed in a hard plastic.
Title: Re: Coupling survey
Post by: Rabs on October 06, 2014, 02:04:59 pm
Hi Belstone,
How easy is it to adjust the separation between wagons with these couplings?  In the second photo above there looks like a big gap between the buffers.  Is it possible to reduce this or people with generous radii on their layouts?
Title: Re: Coupling survey
Post by: belstone on October 06, 2014, 02:32:51 pm
Hi Belstone,
How easy is it to adjust the separation between wagons with these couplings?  In the second photo above there looks like a big gap between the buffers.  Is it possible to reduce this or people with generous radii on their layouts?

The spacing is about the same as standard N gauge couplers.  Ideally it would be closer, but there isn't a lot of scope to reduce it due to the location of the pivot point, and the need to have enough clearance for the magnetic drop arm.  I might have a look at the CAD drawings and see if I can close up the gap a little bit, but having got the geometry spot on I'm reluctant to start messing around with it too much.

You can get the spacing a good bit closer if you can bin the coupler boxes and attach the shank direct to the wagon chassis, but that solution will not suit everyone.

With N gauge couplers there is always going to be a compromise somewhere - size, reliability, ease of assembly / fitment, compatibility with 'train set' curves and points.  I've gone mainly for reliability and ease of assembly, and just hope people don't find the end result too ugly to live with. I'm curious to see whether it will actually work on No.1 Setrack curves - might have to buy a Setrack starter pack and find out.
Title: Re: Coupling survey
Post by: PostModN66 on October 06, 2014, 02:55:26 pm
Hi Richard,

This is a very interesting project - well done for following through!  :thankyousign:

Could you put together a little table of the various types of couplers vs. features?  Features including delayed action, use of fixed magnets, close coupling, ease of assembly, reversability, fit to NEM and Rapido boxes, minimum curve radius etc.

I would find this very illustrative, and position your design nicely.

Cheers   Jon   :)
Title: Re: Coupling survey
Post by: Rabs on October 06, 2014, 08:09:35 pm
You can get the spacing a good bit closer if you can bin the coupler boxes and attach the shank direct to the wagon chassis, but that solution will not suit everyone.

With N gauge couplers there is always going to be a compromise somewhere - size, reliability, ease of assembly / fitment, compatibility with 'train set' curves and points.  I've gone mainly for reliability and ease of assembly, and just hope people don't find the end result too ugly to live with. I'm curious to see whether it will actually work on No.1 Setrack curves - might have to buy a Setrack starter pack and find out.

Good to know, thanks.  I imagine that people who want closer coupling will also want to remove the big ugly box and those that don't, won't!

Ia gree that it's always going to be a compromise so it's good to hear that your solution will be, at least partially, customisable so that people can adjust to their own taste.
Title: Re: Coupling survey
Post by: belstone on October 06, 2014, 09:15:46 pm
Hi Richard,

This is a very interesting project - well done for following through!  :thankyousign:

Could you put together a little table of the various types of couplers vs. features?  Features including delayed action, use of fixed magnets, close coupling, ease of assembly, reversability, fit to NEM and Rapido boxes, minimum curve radius etc.

I would find this very illustrative, and position your design nicely.

Cheers   Jon   :)

I have a table, but can't work out how to post it...
Title: Re: Coupling survey
Post by: belstone on October 07, 2014, 11:25:33 pm
Close coupling - not something I had really thought about until Rabs brought it up, but it's a good point.  So this evening I took two of the wagons which have the couplers attached direct to the chassis (no coupler boxes) and moved the couplers back until the vertical posts were just about touching the headstock, also shortened the plain hook on one end of the '08'. 

(http://i753.photobucket.com/albums/xx178/glencoyne/071014009_zps31db3fd5.jpg)

(http://i753.photobucket.com/albums/xx178/glencoyne/071014001_zpsb68021e6.jpg)

I'm pretty happy with that, and they seem to work as well as before with no buffer locking.  Gangwayed coaches will be tricky due to the vertical bar but there's a bit of room to play with at least on my Farish Mk1s, and using a short plain hook on the loco and fixed short bars between the coaches should work fine, most coaching stock will run as a fixed rake anyway.

The CAD drawing for the Mk3 (hopefully final) etch is now ready to send off.  This incorporates a fold up tab for T-shank conversions and the vertical post is now built into the etch rather than a separate piece of wire.  Getting there, slowly...
Title: Re: Coupling survey
Post by: Newportnobby on October 08, 2014, 10:48:17 am
That does look a whole lot better - many thanks :thumbsup:
Title: Re: Coupling survey
Post by: Jerry Howlett on October 08, 2014, 01:40:44 pm
Yes looking the business.

Jerry
Title: Re: Coupling survey
Post by: Dr Al on October 08, 2014, 03:58:56 pm
How does this work in terms of pushing, in particular long or heavy trains - surely there is a big chance of the couplings overriding and getting tangled up given that they are circular cross section bars?

Cheers,
Alan
Title: Re: Coupling survey
Post by: belstone on October 08, 2014, 04:36:06 pm
Hi Alan

In the coupled position the bars push against the lower half of the vertical post, below the delay bar and are prevented from rising up by the delay bar itself.  In the delayed uncoupling position the hooks push against the pivot which perhaps isn't ideal from an engineer's viewpoint but hasn't given me any problems.  I had a problem early on with bars getting tangled, but the bend at the end (45 degrees up, 90 degrees back after a lot of experimentation) seems to have sorted it.  I must admit I haven't tried propelling more than 10 vehicles yet - this evening I'll couple up everything I have with wheels on it and see what happens. 

Title: Re: Coupling survey
Post by: belstone on October 13, 2014, 08:18:52 pm
Coupler propulsion test ran into a slight problem, which is that the design has now gone through so many modifications that I had to work through all my converted vehicles and update them to the same spec.  I ended up with 11 four wheelers and two Mk1s, which is a fair load:

(http://i753.photobucket.com/albums/xx178/glencoyne/131014_zps1b17b02f.jpg)

I propelled them in both directions across reverse curves, changed around the order of vehicles several times and the only one that gave problems was the horsebox, which has couplers set at the wrong height. Bearing in mind that all the four wheelers have MT restraining springs on the axles to increase drag, that's not a bad performance. Coupler height is however very important - get it wrong and the vehicle tends to be lifted off the rails.
Title: Re: Coupling survey
Post by: belstone on October 17, 2014, 09:09:53 am
Oh dear. Mk3 test etches are here, with the fold up tab for T shank conversions. They fit beautifully, I dropped one into an old Lima horsebox and the height was spot on, but somewhere along the line, while I was trying to close up the distance between vehicles I managed to get the hook dimensions slightly out, only about 0.5mm but enough to stop them coupling up. So I now have two frets of beautiful but useless coupler hooks.  And my drawing file for the Mk2 version has become corrupted so I can't see exactly where I have gone wrong.  Hopefully the etchers still have the Mk2 file I sent them.
Title: Re: Coupling survey
Post by: Newportnobby on October 17, 2014, 01:23:47 pm
Great shame :(
Hope the etchers can sort you out
Title: Re: Coupling survey
Post by: Jerry Howlett on October 18, 2014, 03:45:29 pm
Sure you are  :veryangry: :veryangry: :veryangry:

Hope it works out.

Jerry

Title: Re: Coupling survey
Post by: belstone on October 19, 2014, 09:14:21 pm
The ever helpful folk at PPD emailed me the Mk2 drawing, now amended and ready to send back. If you want small volume etched components I cannot recommend them highly enough.
Title: Re: Coupling survey
Post by: LAandNQFan on October 19, 2014, 09:28:42 pm
Excellent. I love it when a plan comes together!
Title: Re: Coupling survey
Post by: EtchedPixels on October 19, 2014, 10:06:59 pm
The ever helpful folk at PPD emailed me the Mk2 drawing, now amended and ready to send back. If you want small volume etched components I cannot recommend them highly enough.

If you are doing more than small volumes I can recommend them too - the do pretty much all the Etched Pixels bits.
Title: Re: Coupling survey
Post by: belstone on October 28, 2014, 09:23:13 am
Revised Mk3 etches are here and this time I have got the hook dimensions right.  However I changed the angle of the rear vertical bar, just by a few degrees.  Now I have problems propelling long trains, with the coupler bar tending to push upwards and lift the vehicle off the rails.  This was always a slightly dubious aspect of the original design and I was surprised it didn't give any trouble on previous tests. I have two possible fixes for this - either glue an L-shaped buffer plate on the end of the shank (tried that last night, it works but I think it looks ugly) or extend the square shank forwards a couple of mm so that the end of the shank acts as a buffer - much neater and stronger if it works, and will not require me to revise the etch yet again.

NEM adapter project is under way with 3D CAD drawing now done thanks to the very helpful Etched Pixels.  Another couple of evenings of fiddling and I should be about there.  Given that my little layout is just about finished in scenic terms, time to think about my next challenge...
Title: Re: Coupling survey
Post by: Jerry Howlett on October 28, 2014, 07:58:27 pm
Belstone you really do have patience...

Jerry
Title: Re: Coupling survey
Post by: belstone on October 28, 2014, 11:05:43 pm
Belstone you really do have patience...

Jerry

Modelling in N gauge requires Zen-like calm and the ability to laugh in the face of disaster. Luckily I have both qualities. Also I have five thumbs on each hand, a natural talent for breaking small drill bits and worse eyesight than Stevie Wonder. If I can make this coupler system work, anyone can.
Title: Re: Coupling survey
Post by: belstone on October 30, 2014, 12:16:21 am
Truly I am suffering for my art. Every time I change one small part of the design it has a knock-on effect and I find two other things need changing.  Here is this evening's developments, in pictures:

(http://i753.photobucket.com/albums/xx178/glencoyne/291014003_zpsbfa68c01.jpg)

A pair of hooks glued to shanks, with extended ends to act as buffer and holes drilled 0.7mm.  All OK so far, except that the etch isn't quite deep enough for the extended shank and I have to shave a bit off the top. Another drawing amendment required.

(http://i753.photobucket.com/albums/xx178/glencoyne/291014004_zps99c0ef51.jpg)

Wire loop bent up and ready to fit - fine up to the point where I changed the loop design, about which more a little later.

(http://i753.photobucket.com/albums/xx178/glencoyne/291014007_zps9fdbe143.jpg)

Loop threaded through hole in shank and drop arm bent down and back.

(http://i753.photobucket.com/albums/xx178/glencoyne/291014008_zps718f6d06.jpg)

Shank cut to length and tab folded up and glued for Rapido T-shank fitment.

(http://i753.photobucket.com/albums/xx178/glencoyne/291014009_zps36e99600.jpg)

Coupler fitted to chassis, small cube of plastic strip for packing, height set and a drop of cyano to hold everything in place.  This is the first Dapol conversion I have done, pocket is a little narrower than Farish and needs slight trimming but nothing serious.

(http://i753.photobucket.com/albums/xx178/glencoyne/291014011_zpsf842cc20.jpg)

All back together. I haven't painted this one as it will be coming off anyway - coupler box to be chopped off and coupler fitted direct to chassis for closer coupling.

(http://i753.photobucket.com/albums/xx178/glencoyne/291014016_zps38c28a0b.jpg)

I have had no end of problems caused by the open ended loop.  I didn't want a closed loop as this would require soldering which  (a) rules the design out for a lot of people and (b) would probably melt the plastic shank.  But the ends of the loops kept getting tangled up.  Finally I hit on a design which cannot tangle (left hand vehicle) - has to be bent into final shape after loop is fitted to coupler which is why I rejected it initially, but it turns out to be easier than I thought to bend it up, even with coupler on vehicle.  This isn't quite the final version, I reckon I can narrow it slightly to give more clearance on vehicles with oval or Oleo buffers.  But it's pretty close.

Testing showed that the with the new buffer design the loops only just engage with the delay bars and the couplers tend to recouple when propelling over points. There is enough room to extend the delay bar about 0.8mm which will improve reliability a lot. Drawing design revision number 2 of the evening.

Switching to O gauge is starting to look a whole lot more tempting  :veryangry:
Title: Re: Coupling survey
Post by: LAandNQFan on October 30, 2014, 07:55:29 am
 :goggleeyes:  In awe of your patience and accuracy.  I was 5mm out in measuring the panels for my shed! :-[  Tenths of a millimetre??  :thumbsup: :jawdropping: :thumbsup:  :admiration: :thumbsup:
Title: Re: Coupling survey
Post by: belstone on October 30, 2014, 09:35:56 am
My sleep was disturbed by a strange dream in which I was showing my model railway to the Queen and none of my couplers would work. Her Majesty was not amused.  :D So this morning I spent half an hour playing around with the CAD drawing.  I'm getting steadily better at using the software as I start to explore more of the functions - I still have no idea what about 90% of the menu options actually do.

I've widened and deepened the pocket a fraction, extended the delay bar and put a small locating tab on the bottom edge of the hook to ensure the front end of the plastic shank is positioned correctly.  Still thinking about it on the way to work - the clearance between the drop arm and coupler pocket is too tight on the Dapol wagon I converted last night, and I might add another 0.5mm or so between the pivot point and the fold up T shank tab.  This will of course increase coupling distances between vehicles, but the way this coupler is designed you can either have close coupling or T-shank / NEM drop-in compatibility, but you can't have both at the same time.  And no way am I going to move the pivot point forward now that I have the geometry just right.

I'm also going to revive an idea that was in the Mk1 etch but dropped on subsequent versions - a bending guide for the loops incorporated into the fret.  It didn't really work with the strange sigma-shaped loop on the Mk1, but the shape is a lot simpler now.

The revised design works perfectly on-screen with all clearances correct.  So do I order another couple of test etches, or just go for it and commission the first production batch? I'll see how brave I'm feeling once I have the last couple of drawing tweaks done. I'm glad I'm only trying to design a nice simple little coupler and not something properly complicated like a loco kit  :)
Title: Re: Coupling survey
Post by: dogmickb on May 06, 2015, 07:31:55 pm
hi

do you have any more info or progress on your trial coupler?

Regards

Mick
Title: Re: Coupling survey
Post by: belstone on May 10, 2015, 04:28:19 pm
hi

do you have any more info or progress on your trial coupler?

Regards

Mick

Almost six months since I last posted anything, or last did any modelling.  Work and other stuff has got in the way (apart from anything else I made the terrible mistake of agreeing to write a book - 60,000 words, 300 pictures by the end of this month).  So my little layout sits covered in dust and surrounded with broken, failed early versions of my coupler design. Hopefully I'll get back onto it in the next month or so.  The Mk3B etch drawings have been sitting on my computer since the end of October, and I have a small pile of unconverted vehicles picked up cheap on eBay to play with.  I also have a Union Mills tender drive unit to try out on one of the J39s which are still not running as well as they need to.
Title: Re: Coupling survey
Post by: MalcolmInN on June 18, 2015, 05:32:48 pm
agreeing to write a book - 60,000 words, 300 pictures by the end of this month).
Oh I nearly missed this - thanks for the update, sorry to hear about work, yep bit of a nusance that can be , , will be following with interest.

This is too tempting, I cant resist :-
60,000 words and 300 pics., wow, I know we all like pics but that is quite a lot of words to describe your New Couplings project.
Waves joke flag and runs for cover  :bounce: :laugh:

Title: Re: Coupling survey
Post by: belstone on June 18, 2015, 05:48:42 pm
agreeing to write a book - 60,000 words, 300 pictures by the end of this month).
Oh I nearly missed this - thanks for the update, sorry to hear about work, yep bit of a nusance that can be , , will be following with interest.

This is too tempting, I cant resist :-
60,000 words and 300 pics., wow, I know we all like pics but that is quite a lot of words to describe your New Couplings project.
Waves joke flag and runs for cover  :bounce: :laugh:

That isn't my couplings book, it's my book on how to get a Farish J39 to run properly.  The couplings book will be much shorter  :D  I've just ordered a couple of test etches for the Mk 3B version of the design, which will hopefully nail the last few dimensional issues and be a bit easier to assemble accurately.
Title: Re: Coupling survey
Post by: belstone on June 24, 2015, 09:15:37 pm
Mk 3B etches arrived today, and I immediately realised that I have found another way to screw up the CAD drawings.  Half the hooks on each fret are a mirror image of the other half.  Oops.  However that still gives me ten pairs to assemble.  I'm going to concentrate on clip-in fits (no modifications to rolling stock) for this batch, rather than the direct mount close coupled version.  That means I had to buy another locomotive of course, as all mine have had the coupler pockets butchered...  Dapol Class 26 is now on its way. D5307 was a Haymarket engine in 1962 and might have turned up in a rural backwater like Belstone for crew training purposes.  I have half a dozen brand new wagons and a couple of coaches (Dapol and Farish, mixture of NEM and T-shank pockets) to convert, which should keep me busy for a couple of evenings.

I'm thinking about supplying each kit with enough NEM shanks to build all 20 as NEM pattern.  The NEM shanks that Etched Pixels did for me have enough spare material on them to build either 20 NEM, 20 T shank or a mixture of both, and it will save me having to source 2mm square styrene strip separately.  Peco wagons are still bothering me, the T-shank version won't fit in an Elsie pocket and the shank needs to be a bit longer anyway. The coupler pocket is also very wide and gets in the way of the lifting arm.  I don't think these couplers will fit Peco wagons without cutting the coupler pocket off the chassis - but Peco wagon chassis are cheap.
Title: Re: Coupling survey
Post by: belstone on July 05, 2015, 11:56:36 pm
Sometimes you need a bit of luck.  One of the problems I have had is bending the drawbars to the correct dimensions.  I tried making a couple of jigs but could never get a consistently correct shape.  When I did the Mk3B CAD drawings I moved the pivot point slightly relative to the nose of the hook, and as a result the internal dimension of the drawbar loop is now exactly 7/32" x 7/32".  This means that I can bend up the loops round a piece of 7/32" square brass tube (a standard K&S Metals size) and get perfect loops every single time.  Deep joy.  I also made up a very simple jig for drilling the shanks (some strips of Plastikard glued to a piece of hardboard), and now I can put together and fit a pair of couplers in around 10 minutes.  Still a lot longer than snapping in a pair of Easi-Shunts, but these are going to be about a fifth of the price...

The Mk3B couplers turn out to work fine with the earlier Mk2 version, so I made up a few new loops for some of the Mk2s and just had a short but very sweet operating session - about twenty coupling / uncoupling operations, and only one failure to couple, easily fixed by tweaking the end of the hook slightly.  Delayed uncoupling worked 100% - I uncoupled a single van at one end of the layout, propelled it across a reverse crossover and all the way to the far end of the siding at the other end and left it there, all hands free.

I'm still having an occasional problem with the hooks coming unglued from the shanks, and on the NEM version it turns out to be quite hard to get the shank exactly straight on the hook, so I plan to revise the drawing yet again and lengthen the U-shaped section where the shank attaches to the hook, which should fix both problems at once.
Title: Re: Coupling survey
Post by: Newportnobby on July 06, 2015, 09:30:35 am
Your second paragraph sounds very encouraging. Maybe there's hope for us all yet on the delayed uncoupling front.
Title: Re: Coupling survey
Post by: belstone on July 06, 2015, 11:25:13 am
Your second paragraph sounds very encouraging. Maybe there's hope for us all yet on the delayed uncoupling front.

These things work, no question.  The problem is making them easy to assemble for someone other than me:  since I invented them and have spent the last year assembling the little beasties, it's easy to overlook problems which people might face if all they have is an instruction sheet and some components.
Title: Re: Coupling survey
Post by: belstone on July 09, 2015, 11:49:07 pm
I think I just nailed the last big assembly problem.  Ever since the very first prototype I have put a 90 degree bend in the bottom of the drop arm and it has caused all sorts of problems.  I can't even remember why I did it. Very tricky to get the bend in the right place so it doesn't foul on pointwork.  This evening I tried a straight drop arm and it works perfectly...
Title: Re: Coupling survey
Post by: Chris in Prague on July 10, 2015, 07:23:22 am
That's excellent news.
Title: Re: Coupling survey
Post by: belstone on July 10, 2015, 12:07:16 pm
One (and hopefully only one) last round of fiddling still to do:

1. It occurs to me that the central buffer might make the vertical post above the delay bar redundant.  Its purpose is/was to provide something for the drawbars to push against when propelling vehicles, and to stop the drawbar from dropping down behind the delay bar and locking the whole thing solid.  I'm going to build up a few with the vertical post snipped off and see if that works.  If so it will make the coupler look neater and save a bit of space on the etched fret.

2. The drawing needs to be reworked again to extend the support channel for the shank forwards a bit, making the coupler stronger and easier to assemble.  It will also make for a much stronger short shank hook-only version, for locos with NEM pockets that stick out further than they should (e.g. Dapol Class 26). I'll also put another half-etch line at the back end to make it easier to cut the assembly to length for the NEM version.

3. I need to find a source of flexible steel tube, internal diameter around 0.8mm to stick on the end of the drop arm.  The stuff I am using was bought at an exhibition about 30 years ago and was intended for wire-in-tube point operation, but I'm struggling to find anything similar.

Then I need to either knock "Belstone" into exhibitable shape or build a small demo layout and take it to a couple of shows so people can see that the coupler actually works.
Title: Re: Coupling survey
Post by: busbar on July 10, 2015, 02:12:11 pm
I have followed your progress reports with great interest and very much look forward to the finished product being available: from your reports it is obvious that it will be very well researched and developed item.
Good luck with the search for the tube.

Dave
Title: Re: Coupling survey
Post by: belstone on July 12, 2015, 11:52:41 pm
I got a bit sidetracked resurrecting old Poole relics this weekend, but still found time to test my idea of removing the vertical bar.  It works fine- call it Mk 3c. Here's the current state of play, unpainted, on a Farish 16 tonner, showing just how neatly I can bend the drawbar loop with my simple jig. I'm starting to think this might just be a viable product.

(http://i753.photobucket.com/albums/xx178/glencoyne/DSCF4067_zpskofvlyff.jpg)
Title: Re: Coupling survey
Post by: belstone on July 12, 2015, 11:59:58 pm
The "thirty quid special" - Farish 4F (bought as non-runner, £20) with a couple of wagons picked up unboxed for a fiver each.  Loco has the Mk 3c plain hook (no loop).(http://i753.photobucket.com/albums/xx178/glencoyne/DSCF4064_zpsfc1glzig.jpg)
Title: Re: Coupling survey
Post by: Newportnobby on July 13, 2015, 10:33:04 am
Can I ask if it would be possible to post a pic of a couple of items of stock coupled with standard couplings and one with your Mk3 couplings for comparison of closeness please?
 :thankyousign:
Title: Re: Coupling survey
Post by: belstone on July 13, 2015, 11:59:15 pm
Can I ask if it would be possible to post a pic of a couple of items of stock coupled with standard couplings and one with your Mk3 couplings for comparison of closeness please?
 :thankyousign:


It depends how they are mounted, and what spec the original coupler pockets are.  If you do away with the pockets and mount the couplers direct to the chassis you can close the distance right up until the buffers are almost touching, but that isn't great on curves.  From the left: Mk3c in NEM pockets (but the upper vehicle with a longer shank than it actually needs): standard Rapidos: body-mounted Mk2 couplers (same basic dimensions as Mk3)

(http://i753.photobucket.com/albums/xx178/glencoyne/130715%20002_zpsbo8yva9y.jpg)

These three wagons are all on body-mount Mk2s, about the same distance between them as Peco Elsies:

(http://i753.photobucket.com/albums/xx178/glencoyne/130715%20005_zpsk67gmmg0.jpg)

Standard N gauge on the left, Mk2 / 3c combination on the right:

(http://i753.photobucket.com/albums/xx178/glencoyne/130715%20006_zpsv74rdeqq.jpg)
Title: Re: Coupling survey
Post by: Newportnobby on July 14, 2015, 10:22:26 am
Thanks very much for taking time out to do the pics :thumbsup:
Title: Re: Coupling survey
Post by: belstone on July 14, 2015, 11:20:51 am
Had another test session last night, still getting about 90% reliability (three failures in thirty shunting operations) which isn't bad considering I have a mixture of unmodified Mk2s with three different loop designs, reworked Mk2s with new loops, Mk3b and Mk3c, and three different designs of magnetic drop arm. That tells me these things aren't especially fussy about being assembled accurately. One derailment (early Mk2 with incorrectly shaped loop fouling a buffer), one failure to couple (Mk3b in floppy NEM pocket pushing the hook off-centre) and one failure to uncouple (loop on an early Mk2 dropping over the back of the delay bar on a Mk3c).  If one of these couplers doesn't work, there is always a reason.  I'm no longer getting unexplained failures.  Should get the Mk4 drawings done this week and provided I don't screw them up (again) that will be the version that goes into production. Stronger shank attachment, no vertical bar and the back end of the delay bar slimmed down slightly to improve buffer beam clearance on close-coupled installations.

Still need to investigate alternative plastics for the 3D printed NEM adapters - the first batch have a slightly greasy finish and don't seem to take cyano very well even when "keyed" with abrasive paper. I also want to try slightly shorter bar magnets as I think they will work better with the straight drop arm and make the positioning of vehicles over the magnets less critical.  At the moment they have to be placed within 5mm either side of the magnet centre point, which is no problem with locos that run 100% at very slow speeds.  But not every N gauge loco is as good as the 4F and Class 26 that I was using for last night's test.

Title: Re: Coupling survey
Post by: belstone on April 28, 2016, 02:27:00 pm
Whatever happened to my coupler project? Well... I started increasing train lengths and ran into problems.  Unexplained derailments, especially on curves, and couplers locking up and refusing to uncouple.  Then I had to put modelling on one side for a while due to other commitments, and I pretty much gave up on the coupler project.  But at the club last night I was talking to a few people about my attempts to design my own coupler system, and found myself thinking it would be a shame to abandon the whole idea when I had got so close to a coupler design that worked.

So I had a very close look at what was going on with the derailments.  I found three causes.  One is that the delay bars on the last batch were fractionally too long, and in certain circumstances the raised loop of one coupler was getting snagged under the delay bar of the other.  That's easy to fix.

Second cause is trickier, being a fundamental design flaw.  The pivot for the loop sits slightly lower than the hook, so the loops are pulling at a slight angle.  Only a few degrees, but with enough load on them they try to straighten up and lift the front wheels of the first or second wagon off the rails. I have sketched out a revised hook design that allows for a straight pull, need to try and remember how the CAD drawing package works so I can draw it out properly and check that all the other bits still fit. I might be able to shorten the distance between vehicles slightly as well which would be a nice bonus.

Third cause - my idea of extending the shank to form a central buffer is a bad idea.  When propelling vehicles round curves with the loops in the "delay" position the shank-buffers tend to slide sideways against each other and override.  When the track straightens again they lock up and force the vehicles sideways off the track. I can't make the buffers any bigger or they will interfere with the ends of the hooks.  So I am going to try a bar on each hook, extending downwards and at a 45 degree angle sideways.  The idea is that the bars on each vehicle meet in an "X", allowing sideways and vertical movement. Not sure that will work propelling 30 wagons round a 9 inch Setrack curve, but it's worth a try.

So I still haven't given up on the design, not least because it should work with under-track electromagnets, which would be far better in many ways than permanent magnets between the rails - no need to get rid of steel wagon weights for starters.

Richard
Title: Re: Coupling survey
Post by: busbar on April 28, 2016, 03:37:00 pm
Richard

I followed your earlier efforts with interest so am very pleased to hear that you have not abandoned the project. I look forward to further progress reports.

Dave
Title: Re: Coupling survey
Post by: Newportnobby on April 28, 2016, 04:24:15 pm
I have been holding off progressing my small end to end layout as your project was sounding better than the Dapol easi-shunts and....................sorry, Richard, I'm lying through my teeth there but it struck me as a good excuse for me not making any headway :-X
I have followed things with interest and will continue to do so so please keep us informed.
Title: Re: Coupling survey
Post by: belstone on April 28, 2016, 04:29:02 pm
I have been holding off progressing my small end to end layout as your project was sounding better than the Dapol easi-shunts and....................sorry, Richard, I'm lying through my teeth there but it struck me as a good excuse for me not making any headway :-X
I have followed things with interest and will continue to do so so please keep us informed.

Oi! That's MY excuse for not building a layout.  :D
Title: Re: Coupling survey
Post by: Newportnobby on April 28, 2016, 04:30:09 pm
I have been holding off progressing my small end to end layout as your project was sounding better than the Dapol easi-shunts and....................sorry, Richard, I'm lying through my teeth there but it struck me as a good excuse for me not making any headway :-X
I have followed things with interest and will continue to do so so please keep us informed.

Oi! That's MY excuse for not building a layout.  :D

A plagiarist am I :angel:
Title: Re: Coupling survey
Post by: 25901JFM on May 01, 2016, 04:21:24 pm
This is something that interests me and would love to hear more on this project.
John
Title: Re: Coupling survey
Post by: Railwaygun on May 01, 2016, 04:46:57 pm
One (and hopefully only one) last round of fiddling still to do:

3. I need to find a source of flexible steel tube, internal diameter around 0.8mm to stick on the end of the drop arm.  The stuff I am using was bought at an exhibition about 30 years ago and was intended for wire-in-tube point operation, but I'm struggling to find anything similar.


Would sections of guitar strings work??

NICK r
Title: Re: Coupling survey
Post by: belstone on May 03, 2016, 09:56:42 am
One (and hopefully only one) last round of fiddling still to do:

3. I need to find a source of flexible steel tube, internal diameter around 0.8mm to stick on the end of the drop arm.  The stuff I am using was bought at an exhibition about 30 years ago and was intended for wire-in-tube point operation, but I'm struggling to find anything similar.


Would sections of guitar strings work??

NICK r

You might just have solved my problem.  I have a cheap Chinese electric guitar, and the largest string is indeed flexible steel tube.  It's a bit small but bass guitar string might be just right.  It would make very nice vacuum pipes as well.

Richard
Title: Re: Coupling survey
Post by: Black Sheep on December 20, 2017, 09:59:24 am
One (and hopefully only one) last round of fiddling still to do:

3. I need to find a source of flexible steel tube, internal diameter around 0.8mm to stick on the end of the drop arm.  The stuff I am using was bought at an exhibition about 30 years ago and was intended for wire-in-tube point operation, but I'm struggling to find anything similar.


Would sections of guitar strings work??

NICK r

You might just have solved my problem.  I have a cheap Chinese electric guitar, and the largest string is indeed flexible steel tube.  It's a bit small but bass guitar string might be just right.  It would make very nice vacuum pipes as well.

Richard

As a bass player, I think it may be a bit thick for the application, the G string is thicker than the E string on an electric guitar.
I'm due a string change in the new year, you're welcome to my old ones for trial if you want, they're flat wounds so aren't as ridged as 'standard' rotowound strings.

Just been back and read the whole thread start to finish (it's quiet at work this time of year)

It looks neat and very promising, with regards peco wagon pockets being useless for anything but what peco designed them for, they're not that hard to hack off with a stanley knife and fit a Dapol NEM conversion pocket which gives us an added expense but allows the NEM coupling or an NEM rapido to slot in achieving what we're after, reliable coupling options with the ability to revert back to 'standard' for whatever reason.

Alternatively, the coupling can just, with a bit of packing, glue to the under side of the peco wagon.

if you're continuing the project (and I hope you are!) and wish for someone to have a go at assembling some couplings I'd be happy to give a set a go and test them, my test plank is only 80cm long code 55 with an electro magnet and a short point
Title: Re: Coupling survey
Post by: belstone on February 06, 2018, 12:05:19 pm
Another month spent tormenting myself with tiny fiddly bits of brass, wire and plastic.  The problem with these couplers is that when I first came up with the idea I didn't really appreciate all the different things that were going on in the design.  A tension-lock coupler may look simple but it isn't. I managed to solve one problem (the tendency for the first one or two wagons in a long train to be lifted off the track under load) but my solution just shifted the problems to other parts of the design.  I kept fiddling with loop designs and sticking more and more little bits of brass and wire onto the couplers until they looked horrible and didn't work very well either.

I was pondering all this in the bath and came up with a better, neater design which I have spent a week playing around with on the computer screen.  It uses the same basic principles as the previous design (single sided brass wire loop, delayed uncoupling, magnetically operated, fits NEM coupler pockets etc) but should hopefully overcome the main problem I was up against, which was that the last design didn't work especially well when pushing long rakes of vehicles.

I have also been playing around with Chinese electromagnets in two sizes: the smaller one is only just powerful enough to operate the couplers when placed under a length of Finetrax, but the larger one will work below the sleepers on Peco Code 80.

More to come when I have had the first test etch done on the new design.

Richard
Title: Re: Coupling survey
Post by: Newportnobby on February 06, 2018, 02:31:36 pm
Interesting. Thanks for continuing to plug away at this, Richard.
Title: Re: Coupling survey
Post by: Caz on February 06, 2018, 02:48:39 pm
You're a glutton for punishment Richard and I just hope it works out and you come up with something that really works. 

I did start to use B&B/D&G but as the layout is out and back they just didn't work properly as to work reliably they had to be "handed" and when finished with the out and back we had the wrong ends to couple up, shame as they were quite promising.

Title: Re: Coupling survey
Post by: busbar on February 06, 2018, 02:53:07 pm
Richard, you certainly deserve 10 out of 10 for effort and perseverance . Very much looking forward to hearing of a successful outcome. Dave
Title: Re: Coupling survey
Post by: belstone on February 06, 2018, 04:58:19 pm

I did start to use B&B/D&G but as the layout is out and back they just didn't work properly as to work reliably they had to be "handed" and when finished with the out and back we had the wrong ends to couple up, shame as they were quite promising.

I once spent an evening trying to assemble B&B couplers.  After four hours I had a small pile of things that looked like dead houseflies, none of which I much fancied attaching to an item of rolling stock. I  suspect that assembling them takes some practice.  My latest design "borrows" some elements of the DG / B&B design, namely the fold-up hook and buffer bar, but does away with the fiddly latch in favour of a fixed bar (the downside being that remote uncoupling requires a Kadee-style "shuffle"). I agree that single-ended couplers are a pain, not least because you end up having to have a lifting loop on the loco which is usually the most awkward place to have it. I'm aiming for lifting loops both ends of each coach and wagon, and plain fixed hooks on locos. So far I haven't had significant "loop clash" problems like the DG / B&B designs, probably because I am using thicker, heavier wire for the loops.

Richard
Title: Re: Coupling survey
Post by: belstone on February 07, 2018, 07:42:34 am
Sneaky preview of the latest etch design,with built-in NEM compatibility.  I will look at having these done in nickel silver rather than brass for a bit more strength. If there is a weak point it will be where the buffer bar and hook fold up through 90 degrees.


(https://photos.smugmug.com/Scratchbodges/i-qPVgzqf/0/9c798ea6/S/couplershot-S.jpg)
Title: Re: Coupling survey
Post by: belstone on February 07, 2018, 08:01:55 am
Rough workings, checking clearances:

(https://photos.smugmug.com/Scratchbodges/i-zSHxF6f/0/e5597b85/M/coupcalc-M.jpg)
Title: Re: Coupling survey
Post by: Black Sheep on February 07, 2018, 10:56:54 am
Sneaky preview of the latest etch design,with built-in NEM compatibility.  I will look at having these done in nickel silver rather than brass for a bit more strength. If there is a weak point it will be where the buffer bar and hook fold up through 90 degrees.


(https://photos.smugmug.com/Scratchbodges/i-qPVgzqf/0/9c798ea6/S/couplershot-S.jpg)

would it be stronger folded the other way like DG's are or would that affect other parts of the design?
Title: Re: Coupling survey
Post by: belstone on February 07, 2018, 12:53:47 pm


would it be stronger folded the other way like DG's are or would that affect other parts of the design?

I don't think it makes any difference which side of the metal the half-etch is.  The solution will be to add a dab of solder (for the brave) or a glued strip (for the less brave) along the inside of the fold to reinforce it. 

Richard
Title: Re: Coupling survey
Post by: belstone on March 05, 2018, 07:50:14 am
The snow meant a couple of days stuck at home, so I have been messing around with couplers again.  Early tests of the new design looked promising so I cobbled together a test "shunting plank" in Peco Code 55 using second hand points and concrete sleeper track because it was a few pence cheaper than wooden sleepers.  (I have no idea why.)

(https://photos.smugmug.com/Couplers/i-hZS7Gwc/0/f61cad50/M/DSCN1457-M.jpg)

There is a single uncoupler at the entrance to the yard, using one of the round sucker-type Chinese electromagnets under the sleepers.  This did not have enough range to operate the couplers, so I cut away three sleepers and inserted a small (12mm x 6mm by 2mm) piece of steel between the rails on top of the magnet. It is operated using a microswitch attached to my handheld controller, which needs a lot of tidying up vut works fine.

(https://photos.smugmug.com/Couplers/i-3K4HDCh/0/62f2a627/M/DSCN1461-M.jpg)

I fairly quickly found a couple of problems with the design.  First the "hook" is not quite long enough which causes accidental uncoupling on uneven track. With my current layout being in Finetrax I had forgotten what a rough ride four-wheeled wagons can get through a Peco turnout. For now I am soldering strips of brass handrail wire onto the ends of the hooks and filing them to shape which is insanely fiddly but means I can carry on testing without having to order more etches.

Second problem is that the delay bar I built into the etch didn't work very well on curves.  It needs to be in the middle of the coupler, not offset to one side.  I will try to build this into the next etch, for now I am making delay bars from more handrail wire, inserted into a small hole drilled in the end of the shank.  This photo shows the delay bar quite well.  I have experimented with straight and curved ends to the loop,straight seems to work slightly better. 

(https://photos.smugmug.com/Couplers/i-XFfkmsB/0/dd0fcc33/M/DSCN1462-M.jpg)

I am really starting to hate NEM coupler pockets now. There is so much variation in design.  Dapol seem generally better than Farish.  I now have a few of the "clip-in" versions of the coupler assembled and fitted to this Dapol Gresley coach, a Farish "Blue Riband" Mk1 and a Farish A2 Pacific. They work well in a straight line, but the close-coupling mechanism on these coaches causes problems with delayed uncoupling and recoupling on curves. Coaches will usually be in fixed rakes,so the solution might be a bogie-mounted coupler on each end, and Rapidos or fixed knuckle couplers in the middle.



I tried fitting couplers to a Farish brake van with NEM pockets but they sat far too high, flopped about all over the place and stuck out much too far. That last issue seems to be fairly typical of NEM pockets on four-wheeled wagons - too close to the end of the vehicle, making realistic close coupling impossible.  The other test wagons are non-NEM and have the coupler shanks mounted direct to the underframe with small screws.

(https://photos.smugmug.com/Couplers/i-hQqbwS3/0/776cbcb1/M/DSCN1460-M.jpg)

I need to do some more testing once I have upgraded a few of the wagons to the current specification - most of them still have short hooks and offset delay bars. Reliability at the moment is reasonable but not yet good enough. For now I can safely say that the new design has solved the two biggest defects of the previous version, and I don't think it has introduced any new problems. :)

Richard
Title: Re: Coupling survey
Post by: Newportnobby on March 05, 2018, 09:46:16 am
Very interesting, Richard, and far less obtrusive than standard couplings.

I had forgotten what a rough ride four-wheeled wagons can get through a Peco turnout.

So true (sigh)
Title: Re: Coupling survey
Post by: busbar on March 05, 2018, 05:59:47 pm
Well done Richard; things certainly seem to be on the up and I look forward to more news.
Dave
Title: Re: Coupling survey
Post by: Black Sheep on March 05, 2018, 08:31:03 pm
the coupling on the cattle van looks quite low, or is that just the angle of the photo?

glad to hear progress is progressing, I'm hoping you've got these working well soon so I can get on and build the layout :D
Title: Re: Coupling survey
Post by: belstone on March 05, 2018, 11:39:42 pm
the coupling on the cattle van looks quite low, or is that just the angle of the photo?

glad to hear progress is progressing, I'm hoping you've got these working well soon so I can get on and build the layout :D

Not quite as low as it looks in the photo but they do sit a good bit lower than the finescale DG / B&B couplers which are designed to mount level with the bottom of the bufferbeam.  The height on my couplers is dictated by the height of the standard NEM coupler box: unlike the DG coupler they can be bogie-mounted which makes a big difference for the radius of curve they will cope with. Here is a side view of the cattle van: the left hand coupler is actually mounted too high and needs fettling.

(https://photos.smugmug.com/Couplers/i-JFH8X7N/0/df3917d7/M/DSCN1479-M.jpg)

I have built up another four pairs this evening ready to fit to various vehicles, so I can then start testing in earnest.  The etch design really doesn't need a lot of changes now, so provided I don't have any more snags in testing I should finally be able to get some etches out for people to try. I too have a layout held up waiting for me to get these things working properly. 

Richard

Title: Re: Coupling survey
Post by: Black Sheep on March 06, 2018, 10:10:13 am

I have built up another four pairs this evening ready to fit to various vehicles, so I can then start testing in earnest.  The etch design really doesn't need a lot of changes now, so provided I don't have any more snags in testing I should finally be able to get some etches out for people to try. I too have a layout held up waiting for me to get these things working properly. 

Richard

Of course it sits lower due to being in the NEM pocket, how daft of me!

I'm a willing volunteer for testing if required

Title: Re: Coupling survey
Post by: belstone on March 09, 2018, 08:19:37 am
I now have enough vehicles to be able to start testing, so this morning I played with my toy trains over breakfast.

(https://photos.smugmug.com/Couplers/i-twHsDNZ/0/1f859f10/M/DSCN1486-M.jpg)

I am getting pretty good reliability on coupling and uncoupling.  Uncoupling is pretty much 100% provided the vehicles are placed correctly over the magnet.  Coupling is around 95%, occasionally two vehicles will not couple up the first time, but will couple on the second attempt.  I have not had any random self-uncoupling since I increased the size of the hooks slightly. That is probably as good as any of the other systems out there. 

I attached the coupler on the Mk1 to the bogie frame which was nice and easy with the fixed shank design: i removed the NEM pocket and associated hardware, and turned the bogie round 180 degrees to give me a flat bit of plastic to put the mounting screw through.  I also had to make a hole in the top of the bogie frame for the guide pin. All easily returned to standard (bar a couple of small holes underneath) if required. 

(https://photos.smugmug.com/Couplers/i-L62283R/0/e289d746/M/DSCN1487-M.jpg)

The delayed uncoupling facility is less reliable.  It works 100% when propelling in a straight line, but tends to recouple on sharpish curves.  Two of my turnouts are small radius and I cannot propel vehicles reliably through those without them sometimes recoupling. Part of the problem is the delay bars themselves, which as mentioned before are an improvised modification and a bit crude.  I could improve reliability by making the loops wider, but that would make the couplers more obtrusive.

I have been toying with the idea of replacing the fixed delay bars with a DG-style lifting latch, but that would make assembly more fiddly and I like having as few moving parts as possible.  I tried making my own lifting latch mechanism but it really needs to be built into the etch, far too fiddly for my clumsy fingers and tired old eyes to make from scratch. So I will play around a bit more, see if I can refine the fixed bars (I had an idea while typing this which might improve things) and then decide whether I really want to go through yet another redesign.

Richard
Title: Re: Coupling survey
Post by: Black Sheep on March 09, 2018, 02:53:49 pm
I now have enough vehicles to be able to start testing, so this morning I played with my toy trains over breakfast.

(https://photos.smugmug.com/Couplers/i-twHsDNZ/0/1f859f10/M/DSCN1486-M.jpg)

I am getting pretty good reliability on coupling and uncoupling.  Uncoupling is pretty much 100% provided the vehicles are placed correctly over the magnet.  Coupling is around 95%, occasionally two vehicles will not couple up the first time, but will couple on the second attempt.  I have not had any random self-uncoupling since I increased the size of the hooks slightly. That is probably as good as any of the other systems out there. 

Many DG users have their vehicles 'handed' with a loop on one end but not the other for the above reason, and I have operated a 2mm finescale layout where I did occasionally have to use the bufferstop at the end of a siding (and a hedge on another siding) to assist with coupling.
Title: Re: Coupling survey
Post by: belstone on March 09, 2018, 11:59:00 pm

Many DG users have their vehicles 'handed' with a loop on one end but not the other for the above reason, and I have operated a 2mm finescale layout where I did occasionally have to use the bufferstop at the end of a siding (and a hedge on another siding) to assist with coupling.

I am trying to avoid handed vehicles.  On a terminus layout with run round loop you end up needing to have loops on both ends of all your locos, which is the most difficult place to fit them.  (On something like a 2MT 2-6-0 a front coupler with loop would be physically impossible.)  I don't know how bad the loop clash problem is with DG / B&B, but my couplers have much heavier, larger diameter loops which should help a lot. Most of the issues I have had have been more to do with incorrect coupler heights than anything else.

Meanwhile I have been investigating the issue with delayed uncoupling and I am shocked at how bad the geometry is on a small radius Peco turnout.  They are described as 12" radius, but are in effect two straight sections joined by a short, extremely sharp curve, closer to 6" radius than 12".  The result is a really outrageous offset between the vehicle being propelled and the loco propelling it, so the loop slides sideways off the delay bar, then recouples as the vehicles exit the turnout and straighten up.  No amount of fiddling with the coupler design is going to fix this. The photo illustrates the problem nicely: the brake van has already cleared the short curved section and is headed off at a 10 degree angle, while the loco has only just entered the curve and is still pointing straight ahead.

(https://photos.smugmug.com/Couplers/i-rpXQcQX/0/53f3c1ca/M/DSCN1491-M.jpg)

The Peco small radius turnout is not far off an A5 turnout (as supplied by Finetrax) in general dimensions: the difference is that on a proper A5 there is a continuous curve from the frog to the end of the blades, whereas on the Peco version the rails are dead straight from the frog to the blade pivot - see photo below.  I have no idea why Peco designed them this way, a Triang Super Four turnout has better geometry.

(https://photos.smugmug.com/Couplers/i-JS9gkH5/0/16c15e6c/M/DSCN1492-M.jpg)

The coupler design will handle the transition from straight track to Setrack No. 2 curve with no problems, which is better than I expected and shows just how awful the Peco turnouts are. 

Grrr.

Richard
Title: Re: Coupling survey
Post by: Black Sheep on March 10, 2018, 08:17:20 am
hahahahaha  :smiley-laughing:

Guess who's marshalling yard has a string of eight small radius turnouts!  :'(

Do you have to do a shuffle over the magnet to uncouple or simply pass over the magnet with the coupling not under tension?

If the latter then a magnet as you exit the point into the siding would resolve things by simply powering the magnet at the right moment.
Title: Re: Coupling survey
Post by: belstone on March 10, 2018, 09:00:42 am
hahahahaha  :smiley-laughing:

Guess who's marshalling yard has a string of eight small radius turnouts!  :'(

Do you have to do a shuffle over the magnet to uncouple or simply pass over the magnet with the coupling not under tension?

If the latter then a magnet as you exit the point into the siding would resolve things by simply powering the magnet at the right moment.

The couplers need a Kadee-style shuffle over the magnet to set the loop in the delay position, but you are right about the solution - magnets on each exit road rather than at the entry.  For a fan of four sidings like my test plank that means four electromagnets instead of one, which is a pain.  I checked the same two vehicles on a Finetrax B6 turnout where they are fine, and a Peco medium radius (roughly the same size as a B6) which is OK but only just.  The medium Peco is a bit better designed than the shortie, with a gentle curve between the frog and the blade pivot.

N gauge wheel standards don't help. There is so much sideways slop that as the leading wheels run into the turnout, on the small radius one the leading wheelset is already a third of the way along the blades before it starts to change direction.  It then has to change direction by 10 degrees in a length of about 30mm, which makes an effective radius of a little under 8 inches. That's tight.

Richard

Title: Re: Coupling survey
Post by: belstone on March 11, 2018, 11:16:27 pm
I had a day out at the Huntingdon show and came back with a couple of medium radius turnout to replace the nasty small radius ones.  I also acquired a second hand Setrack turnout.  My test shunting "plank" has now been relayed and incorporates what I call the Impossible Siding, a Setrack reverse curve which should test any coupler system to the limit.

So this evening I had a play and found that the delayed uncoupling system works fine on Setrack (9 inch radius) when it didn't work on small radius Streamline (12 inch in theory).  Here's the proof - dropping off a brake van on the Impossible Siding, hands off.  The glitch at the start was caused by the loco getting tangled up with the (temporary) controller cable. The brake van was uncoupled over the magnet just before I started filming as I don't have enough hands to operate camera, controller and magnet switch at the same time...

Title: Re: Coupling survey
Post by: belstone on March 13, 2018, 08:22:38 am
Yesterday my 6-core cable finally arrived, meaning I could tidy up the controller and wiring so it is no longer draped across the track.  I changed the microswitch on the back of the controller for a smaller one - still looks a bit of a lash-up, but works beautifully. 

(https://photos.smugmug.com/Couplers/i-hWHrSvD/0/709bc2c5/M/DSCN1505-M.jpg)

(https://photos.smugmug.com/Couplers/i-dV9D43R/0/b1ffdf97/M/DSCN1506-M.jpg)

So I made another short video, just a loco and a few wagons running backwards and forwards across the magnet, showing how the delay feature works.  A couple of small glitches: the coupler on the back of the cattle wagon needs fettling as the loop is slightly below the horizontal at rest, hence needing a good thump to recouple.  And a demonstration of what happens if you uncouple a single free-running wagon and then propel it off the magnet before letting go of the switch. 

I made a longer video - 8 and a bit minutes of hands-off shunting in and out of all 5 sidings - but the quality wasn't great so I haven't uploaded it. Bearing in mind that the couplers are an improvised lashup with bits glued and soldered to them, things aren't going too badly at the moment. I'll get the revised etch drawings done and sent off to PPD this week, hopefully.  I need to look into chemical blackening of nickel silver as well.

Richard

Title: Re: Coupling survey
Post by: Newportnobby on March 13, 2018, 10:13:36 am
That is very impressive, Richard
Title: Re: Coupling survey
Post by: Black Sheep on March 13, 2018, 11:46:24 am
Chemical blackening I'd leave down to the person building, but would be interested to hear what you use as this is a route I was going to go down when planning to use DG couplings.

Does the coupling have a name yet?

DG
B&B
AJ
Belstone

?
Title: Re: Coupling survey
Post by: belstone on March 13, 2018, 12:07:04 pm
Chemical blackening I'd leave down to the person building, but would be interested to hear what you use as this is a route I was going to go down when planning to use DG couplings.

Does the coupling have a name yet?

DG
B&B
AJ
Belstone

?

The B&B couplers come ready-blackened, I think those are etched in stainless steel. I like the idea as it avoids the risk of clogging up the whole thing with paint.

I am calling this the Magpie coupler - Mag for Magnetic, and Magpie because it shamelessly steals design features from pretty much every tension-lock coupler since the days of O gauge Hornby tinplate :)

Richard
Title: Re: Coupling survey
Post by: Newportnobby on March 13, 2018, 01:02:04 pm
That's just brought back memories of Jenny Hanley  :heart2: presenting Magpie, c/w theme played by the Spencer Davis Group!
 :oopssign: :sorrysign:
Title: Re: Coupling survey
Post by: tutenkhamunsleeping on March 13, 2018, 01:26:50 pm
c/w theme played by the Spencer Davis Group!

 :offtopicsign:
Blimey, never knew SDG did that! Caught Steve Winwood live about 4 years ago - excellent!

 :offtopicsign:
Title: Re: Coupling survey
Post by: Caz on March 13, 2018, 05:40:25 pm
That is looking good Richard, a question, is the coupling handed as that is why I stopped using the likes of B&B etc.
Title: Re: Coupling survey
Post by: belstone on March 13, 2018, 09:08:21 pm
That is looking good Richard, a question, is the coupling handed as that is why I stopped using the likes of B&B etc.

Not handed, that has been one of my requirements from the start as it means I can just have plain hooks on locos which saves an awful lot of hassle.
Title: Re: Coupling survey
Post by: SheldonC on March 18, 2018, 06:37:24 pm
I'm afraid I haven't followed this topic from the beginning, but I have to admire the persistence & ingenuity that have gone into this development; I congratulate you & hope it proves a technical & commercial success.  It's a pity the Rapido became universal at such an early stage.  Incidentally, your mention of aquatic ruminations reminded me that Archimedes did not have his "Eureka!" moment in the shower. :thankyousign:
Title: Re: Coupling survey
Post by: belstone on March 18, 2018, 11:08:55 pm
A really good test session this evening, getting as close as I think I ever will to total reliability.  I put a coupler on the front of my "Old Faithful" J39 and bashed some wagons around the yard for a good half-hour without being seized by a desire to throw my tiny toy trains out of the window. I have found one new problem though.  I was trying to uncouple a single 16 ton mineral wagon and it would not behave.  There was no obvious cause, but in the end I realised that this particular wagon is unusually free-rolling compared to the others in my test fleet. As I attempted to uncouple it, the magnet was drawing it forward by its drop arm towards the wagon I was trying to uncouple from.

This one is going to need a bit of experimenting with magnet configurations and strength to solve. I suspect that what I might need is two magnets with a gap between them, so that the drop arms on the couplers are only pulled downwards and not drawn along the track.  That will be a lot easier to achieve with permanent magnets than electromagnets.

More to report when my super strong Chinese magnets arrive.

Richard
Title: Re: Coupling survey
Post by: Black Sheep on March 19, 2018, 01:31:40 pm
would more weight help, or some paint brush bristles sticking up to offer some resistance help?
Title: Re: Coupling survey
Post by: SheldonC on March 19, 2018, 03:31:35 pm
That is looking good Richard, a question, is the coupling handed as that is why I stopped using the likes of B&B etc.

Not handed, that has been one of my requirements from the start as it means I can just have plain hooks on locos which saves an awful lot of hassle.
One of the advantages of some of the commercially available systems is the availability of couplings of two or three different lengths.  Do you think it's worth considering this as a route to allow those who choose to do so to have a short coupling at one end and a long one at the other, in order to avoid buffer lock on tighter curves than two short ones can cope with?  This "handedness" would be totally at the customer's discretion.
Title: Re: Coupling survey
Post by: Black Sheep on March 20, 2018, 03:34:59 pm
Stupid question (I'm allowed one a month according to my manager)

if propelling over a fixed magnet (not electromagnet) will the couplings uncouple or would you need to stop, 'kadee shuffle' and propell again?

Likewise, pulling over a fixed magnet

just thinking the electromagnet could be used as normal but with a back up of some fixed magnets in the actual siding incase (or to prevent) re-coupling due to a sharp point.

I'm possibly making sense...
Title: Re: Coupling survey
Post by: Newportnobby on March 20, 2018, 03:58:47 pm
I think André-NL came up with a great 'now it's there - now it's not' arrangement for magnets.......

http://www.ngaugeforum.co.uk/SMFN/index.php?topic=28831.0 (http://www.ngaugeforum.co.uk/SMFN/index.php?topic=28831.0)
Title: Re: Coupling survey
Post by: belstone on March 20, 2018, 10:26:57 pm
It is fair to say my solenoid-based uncoupler is not a success.  Pressing the button creates a small earthquake as the armature bangs against its end stop, sufficient to derail any wagons within a foot or so of it.  The solenoid coil draws an alarming current (1.2 amps) and gets hot far too quickly.  I want to try it at a lower voltage but can't lay my hands on a suitable power supply right now.

The permanent magnets themselves are possibly too powerful, I went for big poky N52 magnets in the hope that they would have sufficient range not to need any holes in the baseboard at all. They don't have the range I hoped, and need to be reasonably close to the underside of the sleepers on Peco Code 55 before they do anything.  Slightly closer than that and they do far too much. Magnetic field strength decreases exponentially with distance, so with very powerful magnets the magnet height (relative to the top of the rails) becomes super-critical.  I'm looking for a design which can easily be retrofitted to existing layouts without having to dig up the track, otherwise I would stick with the big round "sucker" electromagnets.

I also remembered something that I had learned with the earlier design but then forgotten, which is that steel wagon weights and mild steel axles are bad news when you are waving magnets around under the track.  One of my cattle wagons had been playing up seemingly at random: I found that it had a mild steel axle on one wheelset, non-magnetic on the other.  (Current Farish wheelsets have non-magnetic axles.)

@newportnobby (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=264) I saw Andre's post and like the design a lot, but ideally I want something that can be operated via a microswitch on my hand-held controller, so mechanical systems are out.

@Black Sheep (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=1230) Earlier versions of the coupler were designed around fixed permanent magnets but I had major problems with accidental uncoupling of the last one or two wagons in a train.  In the end I had to add so much artificial drag to the wagons (via coil springs slipped over the axle ends) that my J39 would slip to a standstill on an eight wagon train.  At that point I gave up with permanent magnets...

@SheldonC (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=3604) The limiting factor on length is the pivot for the arm.  This needs to be roughly level with the bufferbeam, any further back and the arm cannot lift far enough before it hits the vehicle body.  As long as the buffer bar on the coupler sticks out slightly further than the buffers on the vehicle it will handle very sharp curves no problem. On NEM coupler boxes the dropper needs to clear the front of the coupler box, so NEM-equipped vehicles tend to end up not as close-coupled as those where the coupler is mounted direct to the chassis. NEM coupler boxes are totally pants and there is not much I can do about that.  But for locos (where there is no arm to worry about, just a fixed hook and delay bar) I like your idea and will look into it.  Some locos with NEM pockets have the pocket ridiculously far forward (Dapol class 26 for starters) and a shortened hook assembly would make a lot of sense if it can be done.

Shopping list now includes a couple of brass flap hinges, and I am thinking I might have to learn about servos after all.  I also found an interesting post where someone had made their own uncoupling electromagnet for DG couplers (which have a lot in common with mine) so I might acquire some varnished copper wire and try that as well. Isn't this hobby of ours great?  You never need run out of things to do.

Richard
Title: Re: Coupling survey
Post by: T-TRAK_Andrew on March 21, 2018, 05:03:55 am
My perversion of a `drop away' permanent magnet:

https://www.youtube.com/watch?v=fV8shkYND38 (https://www.youtube.com/watch?v=fV8shkYND38)

https://www.youtube.com/watch?v=Z-LSPIym5zM (https://www.youtube.com/watch?v=Z-LSPIym5zM)

https://www.youtube.com/watch?v=5Q0oHMmv7fA (https://www.youtube.com/watch?v=5Q0oHMmv7fA)

Cheers, Andrew G.
Title: Re: Coupling survey
Post by: belstone on March 21, 2018, 07:23:20 am
My perversion of a `drop away' permanent magnet:

https://www.youtube.com/watch?v=fV8shkYND38 (https://www.youtube.com/watch?v=fV8shkYND38)

https://www.youtube.com/watch?v=Z-LSPIym5zM (https://www.youtube.com/watch?v=Z-LSPIym5zM)

https://www.youtube.com/watch?v=5Q0oHMmv7fA (https://www.youtube.com/watch?v=5Q0oHMmv7fA)

Cheers, Andrew G.

Neat and ingenious, thank you for sharing that.  I am looking to do something similar, but with an electrical actuator rather than the manual pushrod.  I just ordered a servo and controller from Heathcote Electronics which I think will do the job. The controller is a simple two position device controlled by an on-off switch, which suits my microswitch system perfectly. I think it would be a good idea to have some kind of compensating spring between the servo arm and the hinge flap but there is no need for them to be mechanically linked: as with your design, the  flap will fall downwards under its own weight as the servo arm moves away.

I had a play around late last night to establish the ideal distance between magnet and rail tops, so I just need the servo kit to turn up and I am back in the uncoupling game.

Richard
Title: Re: Coupling survey
Post by: Black Sheep on March 21, 2018, 09:48:06 am
would the peco / gaugemaster fixed electromagnet work,

It does require drilling a hole for it to come to the top of the baseboard, but it's only a 5mm pole between the sleepers so easy enough to do and camouflage again
Title: Re: Coupling survey
Post by: SheldonC on March 21, 2018, 01:08:14 pm
It is fair to say my solenoid-based uncoupler is not a success.  Pressing the button creates a small earthquake as the armature bangs against its end stop, sufficient to derail any wagons within a foot or so of it.  The solenoid coil draws an alarming current (1.2 amps) and gets hot far too quickly.  I want to try it at a lower voltage but can't lay my hands on a suitable power supply right now.

The permanent magnets themselves are possibly too powerful, I went for big poky N52 magnets in the hope that they would have sufficient range not to need any holes in the baseboard at all. They don't have the range I hoped, and need to be reasonably close to the underside of the sleepers on Peco Code 55 before they do anything.  Slightly closer than that and they do far too much. Magnetic field strength decreases exponentially with distance, so with very powerful magnets the magnet height (relative to the top of the rails) becomes super-critical.  I'm looking for a design which can easily be retrofitted to existing layouts without having to dig up the track, otherwise I would stick with the big round "sucker" electromagnets.

I also remembered something that I had learned with the earlier design but then forgotten, which is that steel wagon weights and mild steel axles are bad news when you are waving magnets around under the track.  One of my cattle wagons had been playing up seemingly at random: I found that it had a mild steel axle on one wheelset, non-magnetic on the other.  (Current Farish wheelsets have non-magnetic axles.)

@newportnobby ([url]http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=264[/url]) I saw Andre's post and like the design a lot, but ideally I want something that can be operated via a microswitch on my hand-held controller, so mechanical systems are out.

@Black Sheep ([url]http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=1230[/url]) Earlier versions of the coupler were designed around fixed permanent magnets but I had major problems with accidental uncoupling of the last one or two wagons in a train.  In the end I had to add so much artificial drag to the wagons (via coil springs slipped over the axle ends) that my J39 would slip to a standstill on an eight wagon train.  At that point I gave up with permanent magnets...

@SheldonC ([url]http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=3604[/url]) The limiting factor on length is the pivot for the arm.  This needs to be roughly level with the bufferbeam, any further back and the arm cannot lift far enough before it hits the vehicle body.  As long as the buffer bar on the coupler sticks out slightly further than the buffers on the vehicle it will handle very sharp curves no problem. On NEM coupler boxes the dropper needs to clear the front of the coupler box, so NEM-equipped vehicles tend to end up not as close-coupled as those where the coupler is mounted direct to the chassis. NEM coupler boxes are totally pants and there is not much I can do about that.  But for locos (where there is no arm to worry about, just a fixed hook and delay bar) I like your idea and will look into it.  Some locos with NEM pockets have the pocket ridiculously far forward (Dapol class 26 for starters) and a shortened hook assembly would make a lot of sense if it can be done.

Shopping list now includes a couple of brass flap hinges, and I am thinking I might have to learn about servos after all.  I also found an interesting post where someone had made their own uncoupling electromagnet for DG couplers (which have a lot in common with mine) so I might acquire some varnished copper wire and try that as well. Isn't this hobby of ours great?  You never need run out of things to do.

Richard

I think it would be possible to overcome the problem of closer coupling by introducing a crank into the lifting arm/loop, provided this did not cause it to foul something else.
Title: Re: Coupling survey
Post by: belstone on March 21, 2018, 03:33:44 pm
would the peco / gaugemaster fixed electromagnet work,

It does require drilling a hole for it to come to the top of the baseboard, but it's only a 5mm pole between the sleepers so easy enough to do and camouflage again


I tried the Peco electromagnet a while ago but it wasn't powerful enough.  From what I have read, that type of electromagnet with a long bar sticking out is a bit inefficient, my own experiments have tended to bear that out.  The Gaugemaster version might be better but it's a bit expensive for something I'm a bit dubious about.

@SheldonC (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=3604) cranking the loop would allow the coupler to be positioned a little further back, but there isn't really any need on non-NEM vehicles, close coupling on these is as good as it will ever need to be already.  On the NEM version the pivot cannot be positioned any further back than the front of the coupler pocket, and most manufacturers put the front of the pocket level with the bufferbeam for some weird unfathomable reason.  The DJM "Mermaid" is an especially good example of what I am up against trying to achieve NEM compatibility with reasonable close coupling. The Farish horsebox and CCT are the opposite extreme, with long buffers and a coupler pocket set well back, needing a longer than standard coupler to avoid buffer locking.

Basically I think I am going to have to give up with plug-in NEM compatibility on rolling stock and just concentrate on providing it for locos which is where it is most needed.  There are just too many design variables, and most vehicles now seem to have coupler boxes on stalks which flop around all over the place. Coaches usually run in fixed rakes, and fitting a coupler to the outer bogie on each rake is pretty easy, at least on the Farish and Dapol coaches I have looked at, and doesn't involve wholesale butchery of the body or chassis. Wagons are cheap enough that most people will (I think) be content to remove the coupler boxes and attach the new couplers to the underframe with small screws. On most Farish stuff this would be a reversible modification as the coupler boxes just clip on. Cutting chunks out of the chassis to fit my couplers on a brand new £120 loco is a less appealing prospect.

The plain hook and buffer for locos doesn't even have to look the same as the one on the full-function looped coupler, as long as it is compatible.  It is more important to have some easy means of adjusting the height to compensate for variations in NEM coupler box design, and that should be achievable with a bit of thought.

Richard
Title: Re: Coupling survey
Post by: belstone on March 23, 2018, 07:54:08 am
I now have a nice simple design for NEM plug-in coupler hooks with easy height adjustment.  The only problem is that it will require soldering - a length of wire soldered at right angles to the coupler, and then the ends snipped off short.  It needs to be soldered to accommodate all the different lengths of coupler that will be needed for NEM equipped locos. Do people think this will be a problem?  I have tried to keep the design soldering-free but I can't see a way around this one. I suppose the pin could be glued, but a round wire on a flat surface doesn't give a lot of contact area, so I am not sure it would really be strong enough, depends on the glue I suppose.  I might try it with thick cyano.

I only have two unmodified locos with NEM coupler pockets, Dapol B1 and Farish A2.  So I made up a rough prototype of my new design and tried fitting it.  To equip these two locos with new couplers front and back I need three different lengths of coupler at two different heights, with two different pin diameters.  So much for the "standard" NEM coupler pocket.
Title: Re: Coupling survey
Post by: Newportnobby on March 23, 2018, 09:52:40 am
Soldering would present a problem for me as I'm just so useless at it. I'd have a go but am more likely to melt the bungalow myself and the layout are housed in :-[
Title: Re: Coupling survey
Post by: Black Sheep on March 23, 2018, 11:09:38 am
The issue I've been having with DG couplings is getting a robust soldered joint between the wire dropper and brass loop, it simply breaks apart so a solder free production would be preferable for me but brass on brass soldering I should be able to achieve.

is it the bar for the NEM mount that's going to be soldered?


I had been attempting to use DG couplings, slipping the bit of brass into the coupling pocket and wedging it in there with a bit of plasticard, allowing an NEM to go back in at a later date, could that be an option, a friction fit?
Title: Re: Coupling survey
Post by: SheldonC on March 23, 2018, 09:57:39 pm
I now have a nice simple design for NEM plug-in coupler hooks with easy height adjustment.  The only problem is that it will require soldering - a length of wire soldered at right angles to the coupler, and then the ends snipped off short.  It needs to be soldered to accommodate all the different lengths of coupler that will be needed for NEM equipped locos. Do people think this will be a problem?  I have tried to keep the design soldering-free but I can't see a way around this one. I suppose the pin could be glued, but a round wire on a flat surface doesn't give a lot of contact area, so I am not sure it would really be strong enough, depends on the glue I suppose.  I might try it with thick cyano.

I only have two unmodified locos with NEM coupler pockets, Dapol B1 and Farish A2.  So I made up a rough prototype of my new design and tried fitting it.  To equip these two locos with new couplers front and back I need three different lengths of coupler at two different heights, with two different pin diameters.  So much for the "standard" NEM coupler pocket.
Personally, I'm not a confident or competent solderer of small things.  As for the "standard" nature of NEM pockets, etc., I've found it quite difficult to fit Farish NEM coupler arms into Dapol NEM coupler pockets.  Examination of the respective suppliers' NEM coupler arms shows they are different.
Title: Re: Coupling survey
Post by: belstone on March 23, 2018, 11:37:45 pm
Thanks for the feedback.  I may have a solution.  I have some square section wire which I bought for an earlier experiment.  This would give a nice flat surface for adhesive bonding.  The wire I have is stainless steel which is not especially easy to glue, but I made a quick test piece and it clipped nicely into an NEM coupler pocket.  The square section wire is available in brass or nickel silver in various sizes, 21 gauge looks about right, the stainless stuff I have is 22 gauge and fractionally small.  I would probably use a slow-setting cyano adhesive so the bar can be accurately positioned, it needs to be square to the shank.

@Black Sheep (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=1230) I don't much fancy trying to solder steel wire to anything.  It is possible but I have never found it easy to get consistently good joints.  The B&B version of the DG coupler uses several turns of fine iron wire wrapped round the drop arm and secured with a dab of cyano, which is the method I have used for my design.
Title: Re: Coupling survey
Post by: belstone on March 24, 2018, 08:16:05 pm
As for the "standard" nature of NEM pockets, etc., I've found it quite difficult to fit Farish NEM coupler arms into Dapol NEM coupler pockets.  Examination of the respective suppliers' NEM coupler arms shows they are different.

So they are.  I just tried to fit a Dapol coupler into a Farish pocket and it is totally solid, will not lift at all.  It also droops downwards.  I get the impression that couplers are a bit of an afterthought for manufacturers.
Title: Re: Coupling survey
Post by: JasonBz on March 24, 2018, 09:27:43 pm
Intersting tales of a heroic struggle here :)

As and aside
you can make the loop and dropper for DG couplings out of a single piece of wire :)
Title: Re: Coupling survey
Post by: belstone on March 27, 2018, 08:39:45 am
Some XXX rated shunting action for a Tuesday morning.  Poor quality video, I really need to get a proper video camera, but you can just about see what is going on.  I fitted a flap-type uncoupler using a heavy brass hinge, but have not yet motorised it as the servo supplied with the control board was rubbish, and I have now dismantled it to see if it was fixable so I can't send it back.  Servos are cheap so I ordered a couple of hopefully better quality ones instead. As @Black Sheep (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=1230) pointed out to me I could mount the magnet direct on the end of the servo arm: the flap was originally intended to work with a solenoid.  It does have the advantage that if a coupler sticks and will not uncouple you can tap the underside of the baseboard with the flap to free it.  Pretty good reliability here, I had a 30 minute session last night with similar results.  That box van needs looking at, I suspect the angle on one of the droppers is wrong, hence the difficulty uncoupling it.

Richard

Title: Re: Coupling survey
Post by: belstone on March 31, 2018, 05:07:02 pm
The first prototype servo-powered uncoupler is now installed and works beautifully even if it looks a bit crude.  The top of the magnet (10 x 10 x 5 N52 Neodymium) sits around 6mm below the rail tops, so even with Peco Code 80 it can be completely hidden.  The same basic principle can be used for other magnetic uncoupling systems (Dapol, Micro Trains etc).  I'm so excited I have even managed to stir myself to complete the design for the latest revised coupler etches...

Richard

(https://photos.smugmug.com/Couplers/i-2FMZLxH/0/a2b4546d/M/DSCN1538-M.jpg)

(https://photos.smugmug.com/Couplers/i-RVktbzR/0/7efd2936/M/DSCN1534-M.jpg)
Title: Re: Coupling survey
Post by: Newportnobby on March 31, 2018, 05:28:12 pm
That's my brain cell blown, then :dunce:
Title: Re: Coupling survey
Post by: Izzy on March 31, 2018, 07:14:40 pm
Intersting tales of a heroic struggle here :)

As and aside
you can make the loop and dropper for DG couplings out of a single piece of wire :)

The only problem I found with that is after a while the wire/loop becomes magnetized and they then stick to each other when coupling up, i.e. won't slide along against each other, and coupling doesn't happen. I now make the whole loop with drop wire in one piece - out of PB wire - and wind a few turns of soft-iron wire on it, which I solder in place.

Izzy
Title: Re: Coupling survey
Post by: belstone on April 01, 2018, 10:07:37 am
(https://photos.smugmug.com/Couplers/i-hQH3CqV/0/e66c9a1e/M/DSCN1540-M.jpg)

A new addition to the test fleet.  I'm on the lookout for more "awkward" vehicles which might cause problems, and a long wheelbase van was high on the list.  This Dapol "Fruit D" turned up unboxed at a fair price. It is the first successful conversion I have done of a wagon with NEM coupler pockets.  The chassis has some very clever spring-loaded pivoting devices to allow for sharp curves but these flapped about all over the place and I couldn't get a consistent height for the couplers, so in the end I put a small nut and bolt through them to lock them up solid.  I also moved them inwards on their mounts for closer coupling. It works fine although the Impossible Siding (Setrack no 2 reverse curve) proved too much for it, buffer locked with the loco and derailed. 

Next on the awkward list is a four wheeled parcels van with long overhangs, either a CCT or PMV.  They seem a bit hard to find at the moment.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 01, 2018, 12:27:57 pm
I changed the thread title as it seemed a bit out of date, and I thought I would do a quick photo sequence as it may not be entirely clear to readers what the Magpie coupler looks like in its current form, or how it works.  So here goes, hope people will find this useful...

(https://photos.smugmug.com/Couplers/i-zZxgg6g/0/6cf7bebb/M/DSCN1544-M.jpg)

The "standard" coupler with lifting loop.  The bar sticking forwards above the coupler is the "delay bar" whose purpose will become clear shortly.  The loop has a drop arm underneath with a few turns of soft iron wire wound round the lower end: when the coupler is positioned over a magnet the iron wire is attracted to the magnet which pulls down the drop arm and lifts the loop.  There is a central buffer bar with a simple flat hook above it bent back at about 30 degrees.

(https://photos.smugmug.com/Couplers/i-Sjj5Qm3/0/d24bba5f/M/DSCN1543-M.jpg)

The couplers are not "handed", coaches and wagons have lifting loops at both ends.  This means locos can have a plain hook and buffer bar without the loop, which makes fitting much easier especially on diesels, and the bogies / pony trucks of steam locos where it would be very difficult to find enough room for the drop arm. This photo shows the delay bar very clearly.

(https://photos.smugmug.com/Couplers/i-Gh9j86P/0/fb521d97/M/DSCN1546-M.jpg)

To couple up the vehicles are simply pushed together.  One loop rides up above the other, the lower loop drops over the hook.  Because the loops are quite large diameter (0.7mm) and heavy the couplers do not suffer as badly as some other designs from "loop clash" where the two loops just ride up against each other.  Usually if these couplers have loop clash it is because one of the loops is not horizontal as it should be.

(https://photos.smugmug.com/Couplers/i-DVvGmdh/0/3f4cc437/M/DSCN1547-M.jpg)

To uncouple, the two vehicles are positioned over the magnet which is activated (electromagnets) or lifted up (permanent magnets) pulling the drop arms downwards.  The vehicles are then drawn slightly apart (maybe 2mm) so that both loops are pulled fully upwards.

(https://photos.smugmug.com/Couplers/i-dmJRTZh/0/8a89a4b0/M/DSCN1548-M.jpg)

Still with the magnet activated, the vehicles are pushed back together.  The loops sit on top of the delay bars, preventing the two vehicles from recoupling.  They can now be propelled to wherever is needed and then will uncouple automatically. So you can shunt a whole fan of sidings with just a single uncoupling magnet at the throat.

These aren't as neat or clever as the DG / B&B finescale couplers with their lifting latches, but they are a lot less fiddly to set up.  The uncoupling "shuffle" will be familiar to anyone who has used knuckle couplers (MicroTrains or Dapol Easishunts).

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: Newportnobby on April 01, 2018, 12:38:35 pm
The loop has a drop arm underneath with a few turns of soft iron wire wound round the lower end

Thanks, Richard. In the first couple of pics I thought " ??? Where's that then?" but in the last 3 pics all became much clearer.
Title: Re: New coupler development (was Coupling survey)
Post by: kirky on April 01, 2018, 05:43:31 pm
(https://photos.smugmug.com/Couplers/i-hQH3CqV/0/e66c9a1e/M/DSCN1540-M.jpg)

A new addition to the test fleet.  I'm on the lookout for more "awkward" vehicles which might cause problems, and a long wheelbase van was high on the list.  This Dapol "Fruit D" turned up unboxed at a fair price. It is the first successful conversion I have done of a wagon with NEM coupler pockets.  The chassis has some very clever spring-loaded pivoting devices to allow for sharp curves but these flapped about all over the place and I couldn't get a consistent height for the couplers, so in the end I put a small nut and bolt through them to lock them up solid.  I also moved them inwards on their mounts for closer coupling. It works fine although the Impossible Siding (Setrack no 2 reverse curve) proved too much for it, buffer locked with the loco and derailed. 

Next on the awkward list is a four wheeled parcels van with long overhangs, either a CCT or PMV.  They seem a bit hard to find at the moment.

Richard

Hi Richard
Thanks for the explanation of how things work. Its all looking very exciting.
Just a question about using the NEM pocket. I think elsewhere you said it was possible to revert back to standard Elsie Rapido couplings after using your Magpie coupler. Just to confirm, this was a 'plug n play' fitting? ie it can be removed and the original coupling used? Just wondering if having to secure the Dapol swinging pocket has made the conversion permanent?
Thanks
Kirky
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 01, 2018, 06:30:50 pm

Just a question about using the NEM pocket. I think elsewhere you said it was possible to revert back to standard Elsie Rapido couplings after using your Magpie coupler. Just to confirm, this was a 'plug n play' fitting? ie it can be removed and the original coupling used? Just wondering if having to secure the Dapol swinging pocket has made the conversion permanent?
Thanks
Kirky

In this case, yes.  The nuts and bolts can be removed leaving just a small hole in the underframe behind the coupler pocket.  However, the implementation of NEM coupler standards by Farish and Dapol is frankly disgraceful, and there will be many vehicles where the only solution is to remove the NEM pockets altogether.  In some cases these just clip on and can be retained for refitting.  Locos tend to actually be easier as there is no lifting loop to worry about and the pockets are not generally designed to move around, I should think most of them will be plug-in conversion with no problems.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 08, 2018, 08:17:20 am
A short and not very exciting video of the uncoupler doing its stuff.  Now controlled by a MERG Servo4 board thanks to @kirky (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=492) . I am happy enough with this design that I will be equipping my layout with uncouplers shortly.

Richard

Title: Re: New coupler development (was Coupling survey)
Post by: kirky on April 08, 2018, 02:04:38 pm
@belstone (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=2569)
How cool is that ! 😎

Cheers
Kirky
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 16, 2018, 07:36:12 am
(https://photos.smugmug.com/Couplers/i-THD3kfz/0/74963ab2/M/DSCN1581-M.jpg)

Right chaps, this is it.  Mk 7 etches are here, 10 thou nickel silver, eight pairs to a fret.  I built up four pairs over the weekend and fitted them to a loco and three wagons. The etches are spot-on in all respects, no more fiddling with the design needed. Phew.

(https://photos.smugmug.com/Couplers/i-QBDrQrM/0/7d69a158/M/DSCN1596-M.jpg)

The B1 has plain couplers (no loop) attached direct to the NEM coupler boxes.  I removed the pivoting inserts and attached the couplers with 12BA bolts through the pivot holes. The Farish brake van uses a similar approach, with the coupler boxes unclipped and a screw through the top pivot hole in the chassis.  The two vans had already been butchered for knuckle couplers and have the couplers screwed to the chassis any old how.

(https://photos.smugmug.com/Couplers/i-qSrNsnJ/0/3d0ea267/M/DSCN1597-M.jpg)

One of my requirements was a design that would fit the coupler pockets on bogie and pony trucks, give reasonably close coupling and still allow full movement from side to side. I think this does the job, doesn't look too bad even unpainted.  A coat of dark grey and it will be pretty inconspicuous.  The bogie had small springs above the axles which didn't seem to do anything useful so I removed them to give a more consistent ride height.  The loco can be returned very quickly to standard (if you hang onto the bits removed) which was another of my requirements. 

I would have done more fiddling if I had the time. I started to put together an assembly photo sequence, but the B1 spat its dummy out as Dapol locos sometimes do.  It now has a Tenshodo motor as the Dapol Supercreep decided it only wanted to run in one direction. Must have been a duff motor from the start as it now runs far better than it ever did.

Next stage is to write some instructions (I did some for a much earlier version several years ago, hope they are still around somewhere) and then I need a few volunteers to test the design and see if they can get the couplers working by following the instructions.  Longer term I am thinking about a website which will show how to fit the couplers to specific models among other things.

It's been a long haul, but at last I can get back to building and operating my model railway...

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 16, 2018, 08:11:15 am
"Close enough" coupling I think.  This train can still be propelled over a Setrack no. 2 reverse curve without buffer locking, but only just.

(https://photos.smugmug.com/Couplers/i-78BqKFC/0/186bfff5/M/DSCN1598-M.jpg)
Title: Re: New coupler development (was Coupling survey)
Post by: Chris in Prague on April 16, 2018, 08:29:45 am
Superb work after tremendous perseverance.
Title: Re: New coupler development (was Coupling survey)
Post by: Newportnobby on April 16, 2018, 09:42:10 am
Your determination to succeed with this project has been remarkable and, although I can't see you being a millionaire this time next year, it does deserve some commercial success so I wish you well. An approach to the likes of the NGS Journal and any of the monthlies might not go amiss :hmmm:
Title: Re: New coupler development (was Coupling survey)
Post by: Bealman on April 16, 2018, 09:49:14 am
Agree with above posts. NPN's suggestions are certainly worth thinking about.  :thumbsup:
Title: Re: New coupler development (was Coupling survey)
Post by: Black Sheep on April 16, 2018, 01:12:05 pm
Your determination to succeed with this project has been remarkable and, although I can't see you being a millionaire this time next year, it does deserve some commercial success so I wish you well. An approach to the likes of the NGS Journal and any of the monthlies might not go amiss :hmmm:

Happy to test build some and write an unbiased review for the NGSJ if required :D
Title: Re: New coupler development (was Coupling survey)
Post by: SheldonC on April 16, 2018, 04:52:43 pm
Your determination to succeed with this project has been remarkable and, although I can't see you being a millionaire this time next year, it does deserve some commercial success so I wish you well. An approach to the likes of the NGS Journal and any of the monthlies might not go amiss :hmmm:
Ditto. :)
Title: Re: New coupler development (was Coupling survey)
Post by: busbar on April 16, 2018, 05:31:02 pm
Well done Richard! I look forward to getting my hands on some when they become available.
Dave
Title: Re: New coupler development (was Coupling survey)
Post by: Caz on April 16, 2018, 05:51:45 pm
A true labour of love, well done Richard.   :thumbsup:
Title: Re: New coupler development (was Coupling survey)
Post by: kirky on April 16, 2018, 06:47:27 pm
Brilliant Richard. You have really done something quite remarkable here - single handedly created a working coupling. Congratulations.

I hope you can get something back on your substantial investment.

cheers
Kirky
Title: Re: New coupler development (was Coupling survey)
Post by: LAandNQFan on April 16, 2018, 11:41:28 pm
I've followed your thread with admiration for your determination, and hope that you have great success with it.  When I've got the scenery done and can start organising trains again...
 :admiration: :admiration: :admiration: :admiration: :admiration:
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 17, 2018, 07:46:18 am
Another fully reversible conversion, this time on a Farish A2. 

(https://photos.smugmug.com/Couplers/i-5bHRJcn/0/7d0606ea/M/DSCN1600-M.jpg)

This was done much the same way as the B1.  I started out by trying to file down the coupler shank to fit in the NEM pocket, but ended up prising out the pivoting insert from the pocket and securing the coupler with a small screw through the pivot holes.

(https://photos.smugmug.com/Couplers/i-Lwc9ZBM/0/9b88660d/M/DSCN1601-M.jpg)

In almost every case this will be a much better solution than trying to make the coupler clip into the pocket like the standard Rapido- shaped couplers do.  The pivoting insert is a nightmare - they waggle around, don't self-centre accurately and make it impossible to get the coupler to sit central and at the right height.  Removing the insert also makes it easy to mount the coupler further back in the pocket.  Ideally the buffer bar on the coupler needs to sit just forward of the buffers on the vehicle, as shown here:

(https://photos.smugmug.com/Couplers/i-RLCWFZs/0/145fd661/M/DSCN1603-M.jpg)

One of the greatest strengths of the design is that it is so versatile.  A 2mm square plastic shank can be adapted to fit almost anything.  I am working on some more tweaks including a "low profile" version to reduce the bulky appearance of the shank underneath the chassis on four wheel wagons.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: AlexanderJesse on April 21, 2018, 04:50:51 pm
Looks great. :NGaugersRule:

How is coupling on curves working? Unfortunately not all sidings can be straight...

Have you already an idea on the pricing? I would have to convert about 100 pieces of rolling stock...

When do you think you can release a beta version to be tested by others?

I must convert and fix coupling on my stock somewhen soon...
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 22, 2018, 09:21:22 am
Looks great. :NGaugersRule:

How is coupling on curves working? Unfortunately not all sidings can be straight...

Have you already an idea on the pricing? I would have to convert about 100 pieces of rolling stock...

When do you think you can release a beta version to be tested by others?

I must convert and fix coupling on my stock somewhen soon...

Coupling on curves is always going to be a problem for any design.  There are several factors: the sharpness of the curve, the distance between outer axle / bogie pivot and coupler face, whether the couplers are fitted and aligned correctly, and finally the massive amount of sideplay in the N gauge wheel/track interface which will cause vehicles to slew sideways on the track. All these factors can combine to prevent the loop from aligning with the hook and dropping over it.  Having said which these couplers will still couple up on a Setrack 2nd radius curve, but reliability on a curve of this radius is not great.

Pricing - I still need to do the costings, but around £1 per pair for the etches and all the other materials. OK, you have to assemble them yourself, but it's still cheap enough.  Bear in mind that you only need to convert vehicles which you intend to shunt with: on fixed rakes of coaches for example, only the outer coupler at each end needs to be changed.

Timetable: I need to sit down and write the instructions which I want to do over the next week.  I have ordered materials to make up 6 - 8 kits for test purposes (8 pairs of couplers to a kit) which will be offered to those people who have expressed an interest in participating in the testing stage.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: AlexanderJesse on April 22, 2018, 09:40:31 am
Well that sounds pretty reasonable.

With Setrack R2 it is possible to plan also small layouts for switching and with the possible to finetune the distance between cars at this price... and the good looks. I'm all in.

As I am not allowed (SWMBO) to work intensively on my hobby I don't qualify as tester of first quality  :uneasy: and, most probably will have to wait for general availabilty...
Title: Re: New coupler development (was Coupling survey)
Post by: Black Sheep on April 22, 2018, 09:57:41 pm

Timetable: I need to sit down and write the instructions which I want to do over the next week.  I have ordered materials to make up 6 - 8 kits for test purposes (8 pairs of couplers to a kit) which will be offered to those people who have expressed an interest in participating in the testing stage.

Richard

If it helps with writing the instructions I'm a graphic designer with some technical drawing ability, although in this day and age it's easy enough to take stage by stage photos and add some text!
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 25, 2018, 07:59:26 am

If it helps with writing the instructions I'm a graphic designer with some technical drawing ability, although in this day and age it's easy enough to take stage by stage photos and add some text!

Thanks for the offer, I think I will be OK as I have written an entire book on how to repair old Land Rovers, but might still take you up on your offer if I run into problems with the illustrations.

For now, here's a short photo sequence showing how the couplers are assembled.  This isn't intended as an instruction manual, just a bit of insight into what is needed to make them.

(https://photos.smugmug.com/Couplers/i-5znFpFq/0/1921c024/M/DSCN1584-M.jpg)

These funny little things are coupler etches as removed from the fret.  Half etched folds on each side to bend up into a U shape, through-etched holes for the loop pivot, and the long thin sticky-out bit is the delay bar.

(https://photos.smugmug.com/Couplers/i-Vpxtzvg/0/260c70ad/M/DSCN1586-M.jpg)

First stage is to fold the buffer bar up sharply through 90 degrees using smooth jaw pliers.  The hook above the buffer bar is then bent back another 30 degrees.  There are no half-etched lines to help with folding as they would weaken the hook and bar.

(https://photos.smugmug.com/Couplers/i-tGQ6P28/0/4d873fed/M/DSCN1589-M.jpg)

The delay bar is now bent upwards 90 degrees and the sides bent along the half-etched lines to form a U-shaped channel.  These are now ready to attach to the shanks.

(https://photos.smugmug.com/Couplers/i-hWxhpVQ/0/c0be5d84/M/DSCN1591-M.jpg)

The coupler etches are now attached to 2mm square styrene strip using cyano adhesive.  The bottom and sides are attached first and squeezed with pliers to ensure they are flat against the shank and all square.  The tab which supports the delay bar is then folded over the top and the delay bar bent to shape with very fine needle nose pliers.

(https://photos.smugmug.com/Couplers/i-3C3jKJn/0/eb14418e/M/DSCN1592-M.jpg)

This shows the final shape of the delay bar.  There needs to be enough clearance for the coupler loop to slide freely between the delay bar and the top of the hook.

(https://photos.smugmug.com/Couplers/i-49WM5gf/0/cbe852b1/M/DSCN1467-M.jpg)

The pivot hole for the loop can be drilled out using the etched holes provided (note: remaining photos show the previous type of coupler which has some design differences, but the operations are the same).  I find it best to drill the hole half way from each side until they meet in the middle, run the drill bit through and move it back and forth like a file to clear the hole.  This minimises any problems caused by the holes being drilled slightly off-square. Now would be a good time to paint the shank.  I am looking into methods of chemically blackening the etches.  You don't want to paint the coupler once assembled as the pivot will gum up.

(https://photos.smugmug.com/Couplers/i-LnKbzHZ/0/63065328/M/DSCN1475-M.jpg)

Loops are bent up from 0.7mm nickel silver wire using a simple jig - a piece of 1/4 x 1/8 brass tube filed down to a U shape.  They can be trued up once bent - a few small tweaks with the pliers to ensure they are all square and not twisted.

(https://photos.smugmug.com/Couplers/i-kgMsGWk/0/4b484c57/M/DSCN1476-M.jpg)

The tail of the loop is passed through the pivot hole ensuring it slides freely...

(https://photos.smugmug.com/Couplers/i-BFHW5tk/0/b359511a/M/DSCN1477-M.jpg)

...and bent down and back to form the drop arm...

(https://photos.smugmug.com/Couplers/i-mgvxd4L/0/52ee8a95/M/DSCN1478-M.jpg)

...which is then cut short with a pair of wire snips.  Again this is the previous Mk 6 coupler and the different design of the delay bar is obvious here.  The drop arm is left slightly longer until the coupler has been fitted to a vehicle: it is then cut to final length (just above rail height when pointing straight down), and half a dozen turns of fine iron wire wrapped round it to attract the uncoupling magnet, and secured with a spot of cyano.

Now all you have to do is decide how to mount it to your loco, coach or wagon.  That's where the fun really starts - more to follow soon.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 26, 2018, 08:22:05 am
A few coupler mounting illustrations, and we will start with the simplest version, mounting the coupler direct to the underframe (coaches and wagons).  This requires the existing coupler box to be removed: on many vehicles the box just clips onto the chassis so the vehicle can be returned to standard.

(https://photos.smugmug.com/Couplers/i-gv4F9mg/0/2323858e/M/DSCN1642-M.jpg)

Coupler conversion at its most basic: Farish ex LMS brake van with the coupler box unclipped, and new coupler installed with a small screw through the shank and into the pivot hole for the NEM coupler insert.  Small pieces of Plastikard are used to shim the coupler so it is the correct height.

(https://photos.smugmug.com/Couplers/i-V5hBXcR/0/8175cc30/M/DSCN1643-M.jpg)

On Peco wagons the coupler box is moulded to the underframe.  Replacement underframes are cheap, so the easiest way out is to cut away the entire coupler box, fill the space with Plastikard and screw the coupler to that.

(https://photos.smugmug.com/Couplers/i-SfMGkXj/0/a6b14f9a/M/DSCN1644-M.jpg)

(https://photos.smugmug.com/Couplers/i-drj297d/0/616aaa2a/M/DSCN1648-M.jpg)

One problem is that the long solid shank is quite visually obtrusive especially on vehicles with long end overhangs.  So I came up with this "skinny" version (grey wagon): the shank is cut off just behind the pivot point and the bottom plate folded up and then back in a Z shape, with a small piece of Plastikard glued across the top to strengthen it. I think the extra effort is worthwhile. Farish 16 ton minerals with the original coupler pockets unclipped, the brown one has nuts and bolts holding the couplers on as I drilled the screw holes in the chassis oversize and the screws wouldn't grip on their own. Oops.

(https://photos.smugmug.com/Couplers/i-tVPp965/0/d085bef5/M/DSCN1649-M.jpg)

For bogie vehicles the coupler can be attached direct to the bogie underframe.  You can see here the advantage of having a straight shank whose length can be varied to suit the application.  This is a Farish Blue Riband Mk1 with the NEM close coupling pocket removed and the bogie rotated through 180 degrees to provide a mounting point - the other end of the bogie frame has a big cutout to clear the original body-mounted coupler box. Again all fully reversible apart from leaving a small screw hole in the bogie frame.

(https://photos.smugmug.com/Couplers/i-JJFJzVL/0/5b76c392/M/DSCN1650-M.jpg)

Dapol wagons have an unusual type of spring-loaded Rapido coupler with part of the pocket being attached to the body, part to the chassis.  I took the same approach with this Hop 21 as with the Peco wagons - cut the whole lot out, reinstate the missing underframe with Plastikard and go from there. 

(https://photos.smugmug.com/Couplers/i-mv6hcRQ/0/dca56706/M/DSCN1652-M.jpg)

The "skinny" couplers work especially well on this wagon which has unusually long overhangs.  Once painted the result should be pretty unobtrusive. 

Coming soon - NEM coupler pockets about which I have nothing good to say.

Richard




Title: Re: New coupler development (was Coupling survey)
Post by: Bealman on April 26, 2018, 08:31:01 am
This is wonderful stuff, and a complete credit to you, Richard.  :thumbsup:

I wish you every success.

But isn't it a shame we have to go to such lengths for decent couplings!
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 26, 2018, 11:25:07 pm
I have had a nagging doubt for a while about the height of the coupler above rail level.  I originally set it using a clip-fit NEM shank coupler on a Farish Mk1 as a reference, which gave me a height of around 3.5mm from rail top to the bottom of the coupler loop.  The first few couplers I fitted were all mounted direct to the vehicle underframes: once I started fitting couplers to vehicles with coupler boxes (locos mainly) I found I kept having to fudge the mountings, bend the couplers downwards etc to get the correct height.  I always seemed to be having to adjust down, never up.

Today I acquired three mint boxed Farish cattle vans with NEM couplers. Almost all my existing rolling stock has already been butchered for bulky MicroTrains coupler boxes and I needed some standard unmodified vehicles to work on.  I have spent the evening playing around with different types of mounting, and as a result it looks like I will have to raise the coupler height by 1mm to allow the couplers to fit standard coupler boxes.  That should still give adequate clearance under the bufferbeam for bogie vehicles, and I think it will make it easier to get the drop arm length right which is one of the more fiddly bits of the assembly process.

The bad news is that I now have four locos, 15 wagons and one coach with couplers the wrong height.  The good news is that they were all going to have to be redone anyway: half of them have makeshift modified Mk 6 couplers which need changing for Mk 7s and the rest are all unpainted and will need to come off and have the loops removed so that they can be given a coat of paint without painting them solid.

Hopefully this will be the last design change.  But I said that last time, and the time before that...

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on April 27, 2018, 10:18:39 am
(https://photos.smugmug.com/Couplers/i-JqLHrxf/0/c188b255/M/DSCN1654-M.jpg)

A bit more fiddling before work this morning.  Excuse the oily thumb, I'm doing engine rebuilds at the moment. This Farish cattle van has a cranked drop arm to clear the front of the coupler box.  Not a new idea but one which featured on my very early designs.  It seemed too fiddly at the time but with the current design of etch, getting the length and angle right is dead easy. So I will build up half a dozen of these to the new standard height and see if the reliability is still OK.

(https://photos.smugmug.com/Couplers/i-4SHCvrc/0/918ac70a/M/DSCN1653-M.jpg)

One disadvantage of using the existing coupler boxes is that you cannot mount the coupler very far back otherwise the drop arm will not clear the front of the box, even the new cranked version.  So close coupling is not as good as it would be if you did away with the coupler boxes.  However, this comparison shot shows that even using coupler boxes, the gap between vehicles is closed up quite a bit compared to the standard N gauge couplers.

Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 01, 2018, 08:29:20 am
(https://photos.smugmug.com/Couplers/i-d6bsPBf/0/9fa6f479/M/DSCN1656_2-M.jpg)

Not much time for coupler development work the last few days, but I have been playing with nasty chemicals to try and blacken the metal bits.  This one was done with Birchwood Casey "Aluminium Black" (recommended on one of the finescale forums for nickel silver) with the white plastic shank touched in with a Sharpie marker pen.  I think the result is pretty satisfactory.  Rather than applying the blackener with a cotton swab as per the instructions I poured it into a plastic tub and dunked the entire etched fret into it.  The loops were bent up and dipped prior to fitting.  The chemical leaves a powdery residue which rubs off easily leaving a very pleasing tarnished black-brown finish which does not seem to scratch or chip when handled.

I am steadily working away at the instructions.  These will be quite long - more like a booklet than an instruction sheet - so the plan is to make them available for free download as a PDF, with an option to purchase printed copies. The coupler kits themselves will not come with printed instructions, just a slip with the download address.

Richard

Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 01, 2018, 08:39:15 am
Beauty and the Beast?

(https://photos.smugmug.com/Couplers/i-vjJjrgd/0/0f508714/M/DSCN1663-M.jpg)
Title: Re: New coupler development (was Coupling survey)
Post by: Black Sheep on May 01, 2018, 08:39:43 am
Perhaps printed copies come with a 'starter pack' with, say, 6 couplings or just one fret of couplings for people to have a go at building them to see if the coupling suits their requirements / fingers

then 'expansion packs' come with larger quantities of couplings but clearly marked as no instructions (as people will keep the instructions from the starter pack)
Title: Re: New coupler development (was Coupling survey)
Post by: Bealman on May 01, 2018, 08:40:34 am
Richard, I think you're a genius.  :thumbsup:

Let's hope that N gaugers are watching, and it takes off!

 :thumbsup: :beers:

George
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 01, 2018, 10:10:41 am
Perhaps printed copies come with a 'starter pack' with, say, 6 couplings or just one fret of couplings for people to have a go at building them to see if the coupling suits their requirements / fingers

then 'expansion packs' come with larger quantities of couplings but clearly marked as no instructions (as people will keep the instructions from the starter pack)

I have thought about a starter pack, with instructions and a couple of magnets to get going with.  One other issue I need to look at, which ties in with the idea of a starter pack, is the assembly jigs.  There are two needed - coupler height, and a loop bending jig. Neither the height nor the loop dimensions are critical in themselves, but if you want your couplers to couple up to ones made by someone else, the height and loop length of your couplers need to be absolutely identical to theirs.  That probably won't happen if people are left to make their own jigs. 

The height gauge is very easy, just a fold-up piece of brass, maybe I could do a "starter etch" with four pairs of couplers and the assembly jigs.  Loop bending jig is more tricky as it needs to be strong enough to bend 0.7mm NS wire around it, so I will have to give that one some thought.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: The Q on May 01, 2018, 10:47:34 am

If it helps with writing the instructions I'm a graphic designer with some technical drawing ability, although in this day and age it's easy enough to take stage by stage photos and add some text!

Thanks for the offer, I think I will be OK as I have written an entire book on how to repair old Land Rovers, but might still take you up on your offer if I run into problems with the illustrations.



Richard

With a large chapter on preventing rainwater leaks? :D
Title: Re: New coupler development (was Coupling survey)
Post by: Black Sheep on May 01, 2018, 10:40:01 pm

I have thought about a starter pack, with instructions and a couple of magnets to get going with.  One other issue I need to look at, which ties in with the idea of a starter pack, is the assembly jigs.  There are two needed - coupler height, and a loop bending jig. Neither the height nor the loop dimensions are critical in themselves, but if you want your couplers to couple up to ones made by someone else, the height and loop length of your couplers need to be absolutely identical to theirs.  That probably won't happen if people are left to make their own jigs. 

The height gauge is very easy, just a fold-up piece of brass, maybe I could do a "starter etch" with four pairs of couplers and the assembly jigs.  Loop bending jig is more tricky as it needs to be strong enough to bend 0.7mm NS wire around it, so I will have to give that one some thought.

Richard

The DG couplings loop jig is sold separately and is a block of brass with a hole through it to hold the end of the wire before wrapping around, the instructions do say you can use pliers, not sure if that's with a measurement on to get it correct each time if such a tool exists
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 02, 2018, 08:10:05 am
A reminder last night of how important the loop bending jig is. Having equipped one cattle van with production-spec couplers (blackened, 4.5mm loop height) I did a second one.  I then found that my couplers had mysteriously become unreliable, sometimes refusing to couple up.  I hadn't changed the design apart from the height setting which shouldn't have caused any problems, and I had been really careful in forming the loops, so what could be wrong?

That last bit provides the answer.  On close inspection my loop bending jig (knocked up in a hurry months ago) had a slope along one face, around 0.3mm from front to back.  For the prototypes I had bent the loops fairly loosely around the jig and tended to form them round the outer end where the jig was widest.  For these latest couplers the loops were wound more tightly due to me taking much more care with the assembly process, and I had formed them around the narrow end.  The result being loops which were fractionally too short to drop over the hooks.

Lesson learned, I will make up a new, more accurate jig and bend some more loops which is no big deal.  There is a range of acceptable lengths for the loops if they are to work, and I hadn't realised how close I was to the bottom of that range.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: Izzy on May 03, 2018, 11:05:13 am

Like probably many others I have been following your developments with interest. The only thing is I am not quite sure how the delayed action part works. Is this the same as DG's with the latch raising up to stop the loop falling down again? Sorry to ask, I have no doubt missed something somewhere

I presume it does, and I ask because with the DG's I have found this won't work with coaches with corridor connections, my latest spec Blue Riband MK 1's, because they stop the latch raising up, which hit the underside of the connections. This isn't a complete disaster for me as I run the coaches in rakes anyway, and so just leave the latches off. Non-corridor coaches are of course fine. My locos only have the latches and no loops so they can still un-couple from them. But I just wondered if you had hit this issue, or whether your design works slightly differently in this respect and the problem doesn't arise.

Just thought I would raise this as you are currently test fitting the latest design to various rolling stock items to find any probs.

cheers,

Izzy
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 03, 2018, 05:49:04 pm

Like probably many others I have been following your developments with interest. The only thing is I am not quite sure how the delayed action part works. Is this the same as DG's with the latch raising up to stop the loop falling down again? Sorry to ask, I have no doubt missed something somewhere

I presume it does, and I ask because with the DG's I have found this won't work with coaches with corridor connections, my latest spec Blue Riband MK 1's, because they stop the latch raising up, which hit the underside of the connections. This isn't a complete disaster for me as I run the coaches in rakes anyway, and so just leave the latches off. Non-corridor coaches are of course fine. My locos only have the latches and no loops so they can still un-couple from them. But I just wondered if you had hit this issue, or whether your design works slightly differently in this respect and the problem doesn't arise.

Just thought I would raise this as you are currently test fitting the latest design to various rolling stock items to find any probs.

cheers,

Izzy

The delayed action system uses a fixed bar above the hook - when the vehicles are drawn apart a couple of millimetres and pushed back together, the fixed bars prevent the loops dropping back over the hooks.  It's simpler than the DG system but not quite as smooth in operation since you need to do a Kadee-style shuffle to set the couplers to the delayed position.

As it happens I fitted the latest spec couplers to a Blue Riband Mk1 last night, along with a Dapol Gresley corridor coach. The only problem I had was that the bottom of the corridor connector on the Gresley prevented the loop from lifting fully.  I was able to shave a small amount off which solved the problem without spoiling the appearance.  The couplers sit a bit lower than DGs which means they can be bogie-mounted which is what I did, removing the complete body-mount coupler assembly, the only problem is that if you install them for close coupling the buffers limit the amount of side to side clearance, which means Setrack curves are out. (I tried.)

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: stephen lewis on May 03, 2018, 06:00:06 pm
Hello Richard,

Beginners question on coupling; I have Farish Panniers with original couplers and Farish/Dapol freight box vans and coal trucks which refuse to couple on the slightest of curves, is this the norm? It also happens with locos and coaches.

Thank you
Steve
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 03, 2018, 08:24:07 pm
Hello Richard,

Beginners question on coupling; I have Farish Panniers with original couplers and Farish/Dapol freight box vans and coal trucks which refuse to couple on the slightest of curves, is this the norm? It also happens with locos and coaches.

Thank you
Steve

Standard N Gauge couplers are getting shockingly bad, I'm sure they never used to be as hopeless back in the "bad old days". Older vehicles with spring loaded couplers are usually OK and the Peco "Elsie" is as nice as it ever was, but I haven't yet seen an NEM-type coupler that actually works properly.  Heights are all over the place and a lot of them will barely lift at all, or else they waggle about in every direction except straight. The Rapido coupler has served us well enough for 50 years but you would have thought the manufacturers would have come up with something better by now.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: SheldonC on May 04, 2018, 03:48:23 pm
As far as coupling/uncoupling on a curve is concerned, my brother (who models in 00, poor dab) reckons the problems are not limited to N Gauge.
Title: Re: New coupler development (was Coupling survey)
Post by: PLD on May 08, 2018, 02:25:46 pm
As far as coupling/uncoupling on a curve is concerned, my brother (who models in 00, poor dab) reckons the problems are not limited to N Gauge.
If the prototype had corners as ridiculously sharp as R1 & R2 set-track equivalent, they would also have issues coupling up on curves!
Title: Re: New coupler development (was Coupling survey)
Post by: Black Sheep on May 08, 2018, 04:14:35 pm
As far as coupling/uncoupling on a curve is concerned, my brother (who models in 00, poor dab) reckons the problems are not limited to N Gauge.
If the prototype had corners as ridiculously sharp as R1 & R2 set-track equivalent, they would also have issues coupling up on curves!

dockyards managed it :D

The whole reason behind the L&Y class 21 (pug) is tight dock yards and industrial environments - something for which ST-5 & ST-6 set track points are ideal!

but otherwise, I completely agree!
Title: Re: New coupler development (was Coupling survey)
Post by: Newportnobby on May 08, 2018, 08:27:38 pm
As far as coupling/uncoupling on a curve is concerned, my brother (who models in 00, poor dab) reckons the problems are not limited to N Gauge.
If the prototype had corners as ridiculously sharp as R1 & R2 set-track equivalent, they would also have issues coupling up on curves!

dockyards managed it :D

The whole reason behind the L&Y class 21 (pug) is tight dock yards and industrial environments - something for which ST-5 & ST-6 set track points are ideal!

but otherwise, I completely agree!

Trouble is, said Pug will probably stall on the set track points :uneasy:
Title: Re: New coupler development (was Coupling survey)
Post by: Black Sheep on May 08, 2018, 08:29:59 pm


dockyards managed it :D

The whole reason behind the L&Y class 21 (pug) is tight dock yards and industrial environments - something for which ST-5 & ST-6 set track points are ideal!

but otherwise, I completely agree!

Trouble is, said Pug will probably stall on the set track points :uneasy:

You have to drive it like you stole it so that it slides through :D

I recall being told that many 08 shunters were missing second gear and had a fair bit of slop in some of their controls due to people being paid per wagon shunted so would hoof it down the siding, stand on the brakes, skid to a stop and so on
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 09, 2018, 11:20:55 pm
Only slow progress the last week or so but I have learned a few things:

1. The cranked drop arms don't work as well as straight ones. Basically you can have close coupling, or couplers that fit to unmodified coupler pockets, but for most coaches and wagons you can't have both.  For locos (which don't have the lifting loop) there is no problem.

2. The optimum size for the lifting loop is an internal dimension of 1/4" x 1/8".  That is a standard size for rectangular brass tube in the KS Metals range which is handy.

3. Having assembled and fitted a few couplers to the new specification (blackened, long loops, 4.5mm loop height) I did a bit of testing and found I had a major "loop clash" issue which hadn't been a problem before.  The cause was the chemically blackened loops which had a matt finish and tended to "pick up" on each other. I used a soft polishing wheel in a minidrill to buff up the front face of the loops and the problem went away. In fact reliability is now better than ever.

(https://photos.smugmug.com/Couplers/i-J8dP3Gj/0/cf93f999/M/DSCN1671-M.jpg)

This evening I had an intensive 30 minute shunting session (12 wagons and two coaches) without having to touch any item of rolling stock.  On the rare occasions where two vehicles did not couple up first time, they always worked on the second attempt.  Delayed uncoupling was 100% reliable throughout. I think I'm about done on development work now.

I thought I might make some short videos showing various aspects of the assembly process, but my camera is totally rubbish (you can barely see the couplers in the test video I made) so this will have to wait until I can afford a better one.  Instructions are still in progress but coming along.

(https://photos.smugmug.com/Couplers/i-bwnPqDt/0/d153669c/M/DSCN1673-M.jpg)

I found this while looking for something else.  It is the very first prototype coupler I made, with hand-filed brass hook, seen here with a final-spec coupler for comparison.  There is a lot wrong with it but you can see most of the basic design elements were there right from the start - heavy open-ended loop, fixed square shank, delay bar and magnet-operated drop arm. How it took so long to get from this to the final design I have no idea.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: AlexanderJesse on May 10, 2018, 12:15:55 am
 :NGaugersRule:
CONGRATULATIONS and a big thank you for the work you have put into this.5
Title: Re: New coupler development (was Coupling survey)
Post by: kirky on May 10, 2018, 09:32:00 am
Only slow progress the last week or so but I have learned a few things:

1. The cranked drop arms don't work as well as straight ones. Basically you can have close coupling, or couplers that fit to unmodified coupler pockets, but for most coaches and wagons you can't have both.  For locos (which don't have the lifting loop) there is no problem.

Hi Richard, brilliant work as ever.
When you say that you can either have close coupling or couplers that fit in unmodified pockets - is the top down photo in post #261 showing coupling in an unmodified pocket, but still has closER coupling than standard couplers? Because if this is your compromise then it is still a significant improvement and we should all be happy with that - I certainly will be.
Thanks again
Kirky
Title: Re: New coupler development (was Coupling survey)
Post by: belstone on May 10, 2018, 10:11:26 am

When you say that you can either have close coupling or couplers that fit in unmodified pockets - is the top down photo in post #261 showing coupling in an unmodified pocket, but still has closER coupling than standard couplers? Because if this is your compromise then it is still a significant improvement and we should all be happy with that - I certainly will be.
Thanks again
Kirky

Those two vehicles have cranked drop arms to clear the front of the coupler box, and I found that the cranked arm didn't uncouple as reliably as a straight one. I ended up cutting a notch in the bottom of the coupler box to clear the drop arm, which still allows the original couplers to be refitted but is obviously a non-reversible modification. With four wheeled wagons, in almost every case it will be easier to remove the coupler boxes altogether (they usually unclip on recent production models) and attach the couplers direct to the underframe.  In the end a true "plug and play" coupler design proved impossible to achieve, but plain hooks (no loop) can be fitted to most locos without modification which is I think the main area of concern.

Richard
Title: Re: New coupler development (was Coupling survey)
Post by: AlexanderJesse on August 08, 2018, 10:40:09 am
Some progress?

When do you expect to open the order-book?
Title: Re: New coupler development (was Coupling survey)
Post by: AlexanderJesse on October 17, 2018, 02:56:46 pm
Any news?
I dearly would like to start fitting my stock with these couplings.