!!

Not Registered?

Welcome!  Please register to view all of the new posts and forum boards - some of which are hidden to guests.  After registering and gaining 10 posts you will be able to sell and buy items on our N'porium.

If you have any problems registering, then please check your spam filter before emailing us.  Hotmail users seem to find their emails in the Junk folder.


Thanks for reading,
The NGF Staff.

Author Topic: New coupler development (was Coupling survey)  (Read 27679 times)

0 Members and 1 Guest are viewing this topic.

Offline Railwaygun

  • Moderator
  • Trade Count: (+2)
  • Full Member
  • ****
  • N Gauge Society Number: 21889
  • Posts: 3875
  • Country: gb
  • Gender: Male
  • Keen on Military Rail, Kato Unitrack, & Z21/DCC
    • Railwaygun, Armoured train and Military Railway group
    • Awards
Re: Coupling survey
« Reply #180 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
This has been a public service announcement
It may contain alternative facts

Caveat lector

The largest Railwaygun, Armoured Train & Military Rail group in the world!
https://groups.io/g/railwaygun/topics

My Military Rail Pinterest area
https://uk.pinterest.com/NDRobotnik/

Motto: Semper ubi, sub ubi

Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #181 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

Offline Black Sheep

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 287
  • Country: gb
  • Gender: Male
    • Awards
Re: Coupling survey
« Reply #182 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
« Last Edit: December 20, 2017, 12:30:20 pm by Black Sheep »

Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #183 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

Online Newportnobby

  • Global Moderator
  • Trade Count: (+60)
  • Full Member
  • *****
  • N Gauge Society Number: 21962
  • Posts: 28664
  • Country: england
  • Gender: Male
    • Awards
Re: Coupling survey
« Reply #184 on: February 06, 2018, 02:31:36 pm »
Interesting. Thanks for continuing to plug away at this, Richard.

Offline Caz

  • Moderator
  • Trade Count: (0)
  • Full Member
  • ****
  • N Gauge Society Number: 23044
  • Posts: 5143
  • Country: es
  • Gender: Female
  • Fairford Branch ticket 1958
    • Twitter
    • YouTube
    • Skype
    • Awards
Re: Coupling survey
« Reply #185 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.


Offline busbar

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 19499
  • Posts: 37
  • Country: gb
  • Gender: Male
    • Awards
Re: Coupling survey
« Reply #186 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

Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #187 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

Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #188 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.



Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #189 on: February 07, 2018, 08:01:55 am »
Rough workings, checking clearances:


Offline Black Sheep

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 287
  • Country: gb
  • Gender: Male
    • Awards
Re: Coupling survey
« Reply #190 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.




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

Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #191 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

Offline belstone

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 842
  • Country: gb
  • Gender: Male
    • Belstone blog
    • Awards
Re: Coupling survey
« Reply #192 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.)



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.



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. 



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.



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

Online Newportnobby

  • Global Moderator
  • Trade Count: (+60)
  • Full Member
  • *****
  • N Gauge Society Number: 21962
  • Posts: 28664
  • Country: england
  • Gender: Male
    • Awards
Re: Coupling survey
« Reply #193 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)

Offline busbar

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 19499
  • Posts: 37
  • Country: gb
  • Gender: Male
    • Awards
Re: Coupling survey
« Reply #194 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

 

Please Support Us!
July Goal: £55.00
Due Date: Jul 31
Total Receipts: £45.00
Below Goal: £10.00
Site Currency: GBP
82% 
July Donations


Advertise Here