N Gauge Forum

General Category => N Gauge Discussion => Topic started by: Old Crow on October 10, 2017, 04:27:08 PM

Title: Light weight and traction issues.
Post by: Old Crow on October 10, 2017, 04:27:08 PM
I'm new so please excuse if this subject has been covered.
I'm just beginning "N" gauge and my last experience was with Hornby Dublo years ago, where the stock was made of "iron!" I note the very light weight of my GF coaches that given half a chance would like to raise a wheel on curves. I'm also intrigued to find the use of tyres on some locos, I guess because of adhesion problems? My query is how in heaven's name do you fit tyres when there's all that delicate watch-like valve motion in the way? I'm thinking you have to be aware of electrical conductivity - so just one set of driving wheels? My loco will be a pre-owned GF Coronation Pacific - original version.

Regarding the light weight. Why not add weight where possible? Has anyone tried roughening the track on inclines or maybe even the driving wheels - or is that total heresy?
Title: Re: Light weight and traction issues.
Post by: daffy on October 10, 2017, 04:38:11 PM
Having no steamers I will leave the tyres problem to others, but on no account should you roughen the wheels or track surfaces IMHO as you will give yourself problems with electrical conductivity, with the probability locos won't run well or at all due to the bad connection.

What adhesion problems are you experiencing?
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 10, 2017, 06:19:50 PM
Definitely NEVER consider roughening track or wheels, that will simply ruin the track or loco.

On steam locos, to fit traction tyres you usually have to remove the crank pin or screw holding the rod to the wheel, then you can slip on a new tyre.  Not all wheels have tyres otherwise there would be insufficient electrical pickup.  The wheels that are intended to have tyres will have a groove in the tread.

Some people do add weight (to simulate the weight of a real coach or wagon), and find it can make models run with less "wobble" but it depends on the model and how much weight is added.  Too much and you're simply adding more load for the poor loco to struggle with.  I'd say don't bother unless you need to. Just because the stock is light doesn't mean it will climb out of curves.  As long as the wheels are free running, the bogies turn easily and the track is well laid you should have no problems.
Title: Re: Light weight and traction issues.
Post by: jpendle on October 10, 2017, 07:53:23 PM
Remember, 'it's just like the real thing'.

On some inclines kettles will need to be double headed or banked, think Lickey Bank or Shap.

But diesels and electrics will be able to handle the same load with no need to bank or double head.

In our miniature world we have a tendency to use tight curves and very steep inclines, which when scaled up, most full size loco's would struggle with.

Regards,

John P
Title: Re: Light weight and traction issues.
Post by: PLD on October 10, 2017, 08:00:12 PM
Quote from: Old Crow on October 10, 2017, 04:27:08 PMI note the very light weight of my GF coaches that given half a chance would like to raise a wheel on curves.
Regarding the light weight. Why not add weight where possible?
It is a fallacy that adding weight improves track holding... The critical factor is the interface of the wheel and rail. i.e. that the track is reasonably well laid to the correct gauge, and the wheels are the correct gauge and profile.
Adding weight to a Loco will improve tractive effort provided it is evenly spread so as not to unbalance the loco (which could reduce haulage capacity!) Adding weight to rolling stock does little other than reduce the number of wagons a loco can move...

Quote from: Old Crow on October 10, 2017, 04:27:08 PMI'm also intrigued to find the use of tyres on some locos, I guess because of adhesion problems? My query is how in heaven's name do you fit tyres when there's all that delicate watch-like valve motion in the way? I'm thinking you have to be aware of electrical conductivity - so just one set of driving wheels? My loco will be a pre-owned GF Coronation Pacific - original version.
they are indeed for traction, and yes it is a trade-off between tractive effort and electrical pick-up...
Do not attempt to fit tyres to a loco that is not designed to have them (the original GF Coronation Pacific is not). it will increase the diameter of the wheels so fitted and result in other wheels being lifted off the track. Locos that are intended to have traction tyres are designed for the valve gear to be detached in the event of needing to change a tyre.

Quote from: Old Crow on October 10, 2017, 04:27:08 PM
Has anyone tried roughening the track on inclines or maybe even the driving wheels - or is that total heresy?
Not recommended... dirt tends to collect in the grooves created.
Title: Re: Light weight and traction issues.
Post by: PLD on October 10, 2017, 08:13:57 PM
Quote from: jpendle on October 10, 2017, 07:53:23 PM
On some inclines kettles will need to be double headed or banked, think Lickey Bank or Shap.

But diesels and electrics will be able to handle the same load with no need to bank or double head.
What utter biassed rubbish...  ::)  :thumbsdown:

The need for double-heading is not about Steam vs Diesel. There are steam and diesel locos that can deliver the required horse-power and other steamers and diesels that can't...
Over Shap (to use one of your examples), no diesel was able to take the 12-14 coach loads a Duchess could take unaided until the class 50s came along and even the early electrics (AL1-4s) tended to double up...
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 10, 2017, 11:37:23 PM
Thanks for the advice guys, yes I thought roughing up the track was a no, no! But I was talking very slight.
And, from the photos, that original Coronation pacific indeed does not use tyres. So - this means that the newer ones actually have a reduced diameter wheel to cater for them? That they are fitted as standard when new? I am thinking of buying a newer one as well.
I want my loco to pull a reasonable load - any one used five or more coaches with one of these?

Talking of Shap - that's the region I used to live in and watch the big pacifics there and the area I would like to model. Not thinking of huge inclines but I could build a straight run of about four feet plus that I'd like to raise to the height that would clear another track say 50- 55mm- is that excessive?


Title: Re: Light weight and traction issues.
Post by: jpendle on October 11, 2017, 12:00:23 AM
Quote from: PLD on October 10, 2017, 08:13:57 PM
Quote from: jpendle on October 10, 2017, 07:53:23 PM
On some inclines kettles will need to be double headed or banked, think Lickey Bank or Shap.

But diesels and electrics will be able to handle the same load with no need to bank or double head.
What utter biassed rubbish...  ::)  :thumbsdown:

The need for double-heading is not about Steam vs Diesel. There are steam and diesel locos that can deliver the required horse-power and other steamers and diesels that can't...
Over Shap (to use one of your examples), no diesel was able to take the 12-14 coach loads a Duchess could take unaided until the class 50s came along and even the early electrics (AL1-4s) tended to double up...

Oh Dear  :sorrysign:

I stand corrected  :D

John P
Title: Re: Light weight and traction issues.
Post by: Delboy on October 11, 2017, 02:13:22 PM
Hi Old Crow,
DCC Concepts do an aid to traction on slopes involving steel plates that go under the track and magnets that you attach underneath your loco chassis. The magnet can also double up if you are using reed switches at various stages of your layout. See the link below:-
https://www.dccconcepts.com/product-category/specialised-model-accessories/dccconcepts-powerbase/ (https://www.dccconcepts.com/product-category/specialised-model-accessories/dccconcepts-powerbase/)
Dennis.
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 11, 2017, 06:38:03 PM
Thanks Delboy, Interesting stuff and looks like an answer. Magnets and steel seem intriguing. Have heard reports of burning out motors if you stress them??? 
I'm new to all this and just realising that with the whole lightweight issue, tolerances are much finer than I'd thought. Seems the world prefers to be largely flat! Just learning you need sensible curves and well laid track.
Still having problems with my Farish Mk1 coach. Seems that one bogie at least has a lot of horizontal play and coach can wobble enough to lift a wheel. Found it runs far better with a little weight (a nut ) over the offending area. Would like to place this inside perhaps, so can you open these coaches?
On the other hand, My original spec pre-owned Duchess behaves beautifully.
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 11, 2017, 08:59:43 PM
Quote from: Old Crow on October 10, 2017, 11:37:23 PM
..I could build a straight run of about four feet plus that I'd like to raise to the height that would clear another track say 50- 55mm- is that excessive?

That works out about 1 in 25, so yes rather steep to be honest.  I think 1 in 40 is a more usual rule of thumb.
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 11, 2017, 09:03:43 PM
Quote from: Delboy on October 11, 2017, 02:13:22 PM
DCC Concepts do an aid to traction on slopes involving steel plates that go under the track and magnets that you attach underneath your loco chassis.

Modern day Magnadhesion for users of non-ferrous track!
Title: Re: Light weight and traction issues.
Post by: mattycoops43 on October 11, 2017, 09:39:32 PM
Quote from: ntpntpntp on October 11, 2017, 08:59:43 PM
Quote from: Old Crow on October 10, 2017, 11:37:23 PM
..I could build a straight run of about four feet plus that I'd like to raise to the height that would clear another track say 50- 55mm- is that excessive?

That works out about 1 in 25, so yes rather steep to be honest.  I think 1 in 40 is a more usual rule of thumb.

Yes, but also bear in mind you can get away with less than 55mm depending on thickness of the bridge. If you don't need to get hand under for access, and can make it strong enough a train will go under a much lower opening.
Title: Re: Light weight and traction issues.
Post by: zwilnik on October 11, 2017, 09:57:14 PM
What about a battery powered banker? :)
Title: Re: Light weight and traction issues.
Post by: daffy on October 11, 2017, 10:20:12 PM
Be aware that differnet locos, even ones that are apparently identical, can have differing abilities when it comes to inclines. If you are running different locos, or will in the future, it is best to err on the side of caution with how much grade you go for. Many believe 1:50, or 2% is a workable limit, but you need to run all your locos in a test with them loaded to the maximum you perceive them being normally used. Some of my Kato electrics will happily take a rake up 3% or more (in tests).
You mention a four foot straight. Is it possible for you to begin the incline before the straight, giving you a longer distance to make the ascent, and thus the ability to reduce the gradient? If so, note that gradients on curves can have a marked negative effect on a locos climbing ability due to increased drag.
Another way to achieve your desired clearance is to look at the problem from both sides - where one track goes uphill, while the one it is crossing is slightly depressed, say at just 0.5% or 1.0 %.
Title: Re: Light weight and traction issues.
Post by: Dorsetmike on October 12, 2017, 10:25:26 AM
If space is limited one alternative is to have the baseboard on a an incline, for example 1% down from left to right and your incline at 1% up left to right, thus halving the distance to achieve the desired clearance.
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 12, 2017, 10:54:27 AM
Quote from: mattycoops43 on October 11, 2017, 09:39:32 PM
Yes, but also bear in mind you can get away with less than 55mm depending on thickness of the bridge. If you don't need to get hand under for access, and can make it strong enough a train will go under a much lower opening.

I found on my last layout that so called 2" thick timber is now 44mm and that all my steam and diesel locos would pass under that with no problems (baseboard to underside of overpass). I can foresee issues if you have electric locos with pantographs though :uneasy:
If you need under board point motors in such a place that would be a no-no.

Quote from: Zwilnik on October 11, 2017, 09:57:14 PM
What about a battery powered banker? :)

I had one of those but then they closed the local branch ::)

Title: Re: Light weight and traction issues.
Post by: Old Crow on October 13, 2017, 12:40:06 AM
Thanks guys for all the advice, much appreciated by a newbie. Yes, regarding just how petite the rolling stock is in N gauge it seems one can get away with a good bit less than 2 inches.
Title: Re: Light weight and traction issues.
Post by: njee20 on October 13, 2017, 09:09:26 AM
Quote from: PLD on October 10, 2017, 08:00:12 PM
It is a fallacy that adding weight improves track holding... The critical factor is the interface of the wheel and rail. i.e. that the track is reasonably well laid to the correct gauge, and the wheels are the correct gauge and profile.
Adding weight to a Loco will improve tractive effort provided it is evenly spread so as not to unbalance the loco (which could reduce haulage capacity!) Adding weight to rolling stock does little other than reduce the number of wagons a loco can move...

It's not a fallacy, but arguably is a compensation for poorly laid track. Something like the Dapol IKA Megafret container flats have tiny wheels and weigh very little. I find with a reasonable train that they'll derail on anything but perfect, flat, straight track, including the weight of the train pulling them off the inside of sharper curves if you're not careful. Adding containers (preferably themselves with added weight) turns them into very acceptable runners.
Title: Re: Light weight and traction issues.
Post by: Delboy on October 13, 2017, 02:25:43 PM
Quote from PLD.
QuoteAdding weight to rolling stock does little other than reduce the number of wagons a loco can move...

I have just acquired a set of 3 Farish pre-weathered steel tippler wagons (377-279) which are so light that, without some added weight, you cannot even couple them up to the loco unless you interfere manually, suggesting that weighting is required in some of the N gauge rolling stock.
Dennis.
Title: Re: Light weight and traction issues.
Post by: Dorsetmike on October 13, 2017, 03:46:11 PM
I've got a vague recollection of somebody producing locos with wheel treads milled like the edge of a coin back in the 50s, didn't catch on. Probably as suggested earlier in the thread due to dirt collection.
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 13, 2017, 03:56:56 PM
Quote from: Dorsetmike on October 13, 2017, 03:46:11 PM
I've got a vague recollection of somebody producing locos with wheel treads milled like the edge of a coin back in the 50s, didn't catch on. Probably as suggested earlier in the thread due to dirt collection.

Triang.   Bloody noisy things which collected grot in the knurls.
Title: Re: Light weight and traction issues.
Post by: Railwaygun on October 13, 2017, 06:50:02 PM
Quote from: Dorsetmike on October 13, 2017, 03:46:11 PM
I've got a vague recollection of somebody producing locos with wheel treads milled like the edge of a coin back in the 50s, didn't catch on. Probably as suggested earlier in the thread due to dirt collection.

the world record holder for N gauge traction was a DD-40 x2 with a depleted uranium frame & milled wheels! 1103 waggons!

- Jim Fitzgerald's custom built "Cotton Brutes"

http://www.railpage.com.au/f-t11317790.htm (http://www.railpage.com.au/f-t11317790.htm)

from RMWeb

As a matter of interest, uranium has been used (legally) for model locos. Jim Fitzgerald built two N scale "Cotton Brutes" back in the early 80s. They were double length Minitrix U30s with 24oz (680g) frames milled from depleted uranium. He worked for an aerospace contractor and had access to "offcuts". Each loco was powered by two Sagami can motors.

In November 1982, one of these locos hauled 513 wagons from a standing start. The two locos together hauled 778 wagons. The train was 6.625 scale miles long. This is a photo of the 778 wagon train (the front and rear of the same train).

At the 1983 NTRAK convention a single Cotton Brute hauled 560 wagons on its own. The two then hauled 950 wagons for 3 hours. They couldn't put on any more as the layout wasn't big enough.

In 1984 the two hauled 1103 wagons, but nobody had the foresight to call Guinness!
Title: Re: Light weight and traction issues.
Post by: Dorsetmike on October 13, 2017, 07:06:39 PM
My best was a Langley S15 kit on a Fleischmann 7161 chassis with 8 wheel tender drive, back in the 80s on my loft layout, 42 bogie coaches, a mix of Farish Mk1, Minitrix Mk1 and older Farish. I'd also turned grooves in the rear drivers of Black 5s and a 4P, the 4P managed 15 Mk 1s
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 14, 2017, 12:17:36 AM
My issue is with a GF Mk1 coach with one misbehaving bogie - really doesn't like curves or being pushed. Does run well with a bit of weight but how to add. Ideally I'd like to hide it internally. Can you dismantle these coaches without damaging them?
Title: Re: Light weight and traction issues.
Post by: PLD on October 14, 2017, 12:44:08 AM
Quote from: Old Crow on October 14, 2017, 12:17:36 AM
My issue is with a GF Mk1 coach with one misbehaving bogie - really doesn't like curves or being pushed. Does run well with a bit of weight but how to add. Ideally I'd like to hide it internally. Can you dismantle these coaches without damaging them?
If one bogie misbehaves and the other doesn't the problem is with that bogie and nothing to do with the weight of the coach as a whole, otherwise both bogies would be liable to the same issue...  ::)

Most likely either an out of gauge wheel set or something is restricting the turning of that bogie...
Title: Re: Light weight and traction issues.
Post by: PLD on October 14, 2017, 12:49:38 AM
Quote from: njee20 on October 13, 2017, 09:09:26 AM
Quote from: PLD on October 10, 2017, 08:00:12 PM
It is a fallacy that adding weight improves track holding... The critical factor is the interface of the wheel and rail. i.e. that the track is reasonably well laid to the correct gauge, and the wheels are the correct gauge and profile.

It's not a fallacy, but arguably is a compensation for poorly laid track. Something like the Dapol IKA Megafret container flats have tiny wheels and weigh very little. I find with a reasonable train that they'll derail on anything but perfect, flat, straight track, including the weight of the train pulling them off the inside of sharper curves if you're not careful. Adding containers (preferably themselves with added weight) turns them into very acceptable runners.
If they're the ones I'm thinking of, the wheel profile is horrid with no transition from tread to flange... Adding weight may help, but as you say it's compensation for rather than addressing the root cause which isn't simply lack of weight...
Title: Re: Light weight and traction issues.
Post by: PLD on October 14, 2017, 12:54:01 AM
Quote from: Delboy on October 13, 2017, 02:25:43 PM
Quote from PLD.
QuoteAdding weight to rolling stock does little other than reduce the number of wagons a loco can move...

I have just acquired a set of 3 Farish pre-weathered steel tippler wagons (377-279) which are so light that, without some added weight, you cannot even couple them up to the loco unless you interfere manually, suggesting that weighting is required in some of the N gauge rolling stock.
Dennis.
That's not a weight of the wagon issue, that down to the strength of the coupling springs (Peco wagons are among the lightest yet their unsprung couplings take the least force to couple up...) Answer to that one is to ease the springs - cut about a quarter off the length of the spring, then stretch the remainder to the original length.
Title: Re: Light weight and traction issues.
Post by: njee20 on October 14, 2017, 09:28:08 AM
Quote from: PLD on October 14, 2017, 12:49:38 AM
If they're the ones I'm thinking of, the wheel profile is horrid with no transition from tread to flange... Adding weight may help, but as you say it's compensation for rather than addressing the root cause which isn't simply lack of weight...

Adding weight does help. That's a fact. The other option is to have them virtually unusable. The wheel size is a compromise for the scale. So it's not a fallacy at all. Pretty weird stance actually. I assume you take any weights out of stock to make them easier to haul?
Title: Re: Light weight and traction issues.
Post by: Delboy on October 14, 2017, 11:11:12 AM
Quote from PLD,

QuoteThat's not a weight of the wagon issue, that down to the strength of the coupling springs (Peco wagons are among the lightest yet their unsprung couplings take the least force to couple up...) Answer to that one is to ease the springs - cut about a quarter off the length of the spring, then stretch the remainder to the original length.

Thanks for the info but that seems a lot of fiddly work to have to mess about with the tiny springs on 6 couplings. Think I will stick to adding a little weight to each wagon and solve it that way.
Title: Re: Light weight and traction issues.
Post by: mickd247 on October 14, 2017, 01:04:47 PM
Quote from: Old Crow on October 14, 2017, 12:17:36 AM
My issue is with a GF Mk1 coach with one misbehaving bogie - really doesn't like curves or being pushed. Does run well with a bit of weight but how to add. Ideally I'd like to hide it internally. Can you dismantle these coaches without damaging them?

A couple of other suggestions concerning the misbehaving bogie. As well as the BtoB of the axles, check that the retaining pin is not pushed in too far and restricting the bogie turning and also remove the bogie and check it and the shaft on the chassis that it sits on for manufacturing flash which may be restricting movement.

As far as adding weight, it might be better to add strip weight to the underside of the chassis between the bogies keeping the weight and CofG lower than adding weight inside the body.

HTH

:beers:

Mick
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 14, 2017, 01:32:16 PM
Quote from: Delboy on October 14, 2017, 11:11:12 AM
Quote from PLD,

QuoteThat's not a weight of the wagon issue, that down to the strength of the coupling springs (Peco wagons are among the lightest yet their unsprung couplings take the least force to couple up...) Answer to that one is to ease the springs - cut about a quarter off the length of the spring, then stretch the remainder to the original length.

Thanks for the info but that seems a lot of fiddly work to have to mess about with the tiny springs on 6 couplings. Think I will stick to adding a little weight to each wagon and solve it that way.

Must admit I have a branch line train running with an Ivatt 2-6-2T and 2 x Farish Stanier brake ends and there's no way I can just back the loco slowly onto the coaches and couple up as the coaches just dance away down the loop :doh: If I would have to mess with the coupling springs I think the finger of God will remain in play :hmmm:

As far as weights are concerned you can buy small fishing weights (smaller than a Fisherman's Friend :D) which could be glued under the chassis so I might try that myself one day.
Title: Re: Light weight and traction issues.
Post by: martyn on October 14, 2017, 01:36:46 PM
Another thing to check on a dodgy bogie-ensure the pin point axle ends are actually in the moulded axlebox-they sometimes don't go right in and distort the bogie shape as well as not being horizontal.
Martyn
Title: Re: Light weight and traction issues.
Post by: martyn on October 14, 2017, 01:39:21 PM
NPN;

'Must admit I have a branch line train running with an Ivatt 2-6-2T and 2 x Farish Stanier brake ends and there's no way I can just back the loco slowly onto the coaches and couple up as the coaches just dance away down the loop :doh: If I would have to mess with the coupling springs I think the finger of God will remain in play :hmmm:'

Fit B+Bs............. :) :)-but the finger of God is easier!

Martyn (!)
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 14, 2017, 01:42:47 PM
Quote from: martyn on October 14, 2017, 01:39:21 PM
Fit B+Bs............. :) :)-but the finger of God is easier!
Martyn (!)

@martyn (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=447)

B + Bs? ??? :dunce:
Title: Re: Light weight and traction issues.
Post by: martyn on October 14, 2017, 01:49:37 PM
NPN;

B+Bs are one of the remote coupling types, operated by magnets, as also, eg DG couplings-see posts in 'Coupling Review' folder.

They are an exercise in metal origami, but when adjusted correctly require only a light coupling buffer to buffer touch to operate.

PLD has posted quite a lot on the subject, and we use them on James St.

Martyn
Title: Re: Light weight and traction issues.
Post by: Dorsetmike on October 14, 2017, 02:53:47 PM
For weight  I find the easiest solution is "Liquid Gravity" fromvarious suppliers, Amazon, Ebay among others think this Amazon one works out cheapest, I've seen some on Ebay for £9+ but by the time you add £2.40 or so P&P ... ...

https://www.amazon.co.uk/DLXBD038-Deluxe-Materials-Liquid-Gravity/dp/B00AMB74OC/ref=sr_1_1?ie=UTF8&qid=1507988395&sr=8-1&keywords=liquid+gravity (https://www.amazon.co.uk/DLXBD038-Deluxe-Materials-Liquid-Gravity/dp/B00AMB74OC/ref=sr_1_1?ie=UTF8&qid=1507988395&sr=8-1&keywords=liquid+gravity)

Pour what you need and add glue, super, PVA, epoxy etc; for under a vehicle I'd mix some 2 part epoxy &  mix in some liquid gravity, put vehicle upside down and spread the mix, just keep clear of wheels and axles!
Title: Re: Light weight and traction issues.
Post by: railsquid on October 14, 2017, 03:08:52 PM
It might also be worth considering new wheelsets, have rewheeled a lot of older stock (not just Farish) with these: http://www.hattons.co.uk/23580/Graham_Farish_379_412_Axles_with_coach_wheels_Pack_of_10/StockDetail.aspx (http://www.hattons.co.uk/23580/Graham_Farish_379_412_Axles_with_coach_wheels_Pack_of_10/StockDetail.aspx)
Title: Re: Light weight and traction issues.
Post by: mattycoops43 on October 14, 2017, 09:30:57 PM
Quote from: PLD Answer to that one is to ease the springs - cut about a quarter off the length of the spring, then stretch the remainder to the original length.
/quote]

Sorry to correct you but I have to. Cutting a spring shorter, then stretching it to the original length makes it stiffer. That is just physics, softer springs always have more coils per inch. If you have had a good result from this, I would suspect the spring is just shrinking back slightly so there is some play, in other words the coupling has some wobble in it.
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 14, 2017, 10:27:35 PM
Interesting points guys; it does seem to be a rogue bogie that I've had a good look at. But those coaches are so light you could blow them round. I don't need a lot of weight but just a small square hidden somewhere underneath - certainly rides better.
Title: Re: Light weight and traction issues.
Post by: Railwaygun on October 15, 2017, 01:52:56 PM
Quote from: Dorsetmike on October 14, 2017, 02:53:47 PM
For weight  I find the easiest solution is "Liquid Gravity" fromvarious suppliers, Amazon, Ebay among others think this Amazon one works out cheapest, I've seen some on Ebay for £9+ but by the time you add £2.40 or so P&P ... ...

https://www.amazon.co.uk/DLXBD038-Deluxe-Materials-Liquid-Gravity/dp/B00AMB74OC/ref=sr_1_1?ie=UTF8&qid=1507988395&sr=8-1&keywords=liquid+gravity (https://www.amazon.co.uk/DLXBD038-Deluxe-Materials-Liquid-Gravity/dp/B00AMB74OC/ref=sr_1_1?ie=UTF8&qid=1507988395&sr=8-1&keywords=liquid+gravity)

Pour what you need and add glue, super, PVA, epoxy etc; for under a vehicle I'd mix some 2 part epoxy &  mix in some liquid gravity, put vehicle upside down and spread the mix, just keep clear of wheels and axles!

do not use PVA - some varieties contain acetic acid which may cause the lead to be converted to lead acetate, causing the ballast to swell!

this may cause disaster if the ballast is in a confined space!
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 15, 2017, 02:26:53 PM
Quote from: Railwaygun on October 15, 2017, 01:52:56 PM

do not use PVA - some varieties contain acetic acid which may cause the lead to be converted to lead acetate, causing the ballast to swell!

this may cause disaster if the ballast is in a confined space!

Nick is right. I have read this before on the forum, and some of the results have been quite catastrophic!
Title: Re: Light weight and traction issues.
Post by: njee20 on October 15, 2017, 02:48:56 PM
Liquid gravity isn't actually lead IIRC, so should be ok.
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 15, 2017, 02:53:40 PM
Thanks guys for the thoughts and links - never heard of "liquid gravity" or the "lead/pva disease before and the link to wheel sets is very useful.
Probably be adding a small square of steel somewhere out of sight below.
Title: Re: Light weight and traction issues.
Post by: njee20 on October 15, 2017, 03:24:57 PM
You can also get self adhesive lead strip (for window decorations etc), which is quite handy.
Title: Re: Light weight and traction issues.
Post by: Delboy on October 15, 2017, 03:31:45 PM
I have some self adhesive lead strip and intend to use it in my rolling stock. I am not to sure I would risk it underneath them in case they came off and caused a short.
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 15, 2017, 08:13:32 PM
Quote from: Delboy on October 15, 2017, 03:31:45 PM
I am not to sure I would risk [lead strip] underneath them in case they came off and caused a short.
Paint the lead - you wouldn't want shiny metal showing anyway - that'll help insulate it in the rare event it did fall off.     
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 15, 2017, 10:10:20 PM
Yes! Think I'm going to go down the road of adding a little weight disguised below; I do think those coaches are very light indeed. But have you more experienced guys had good results with them?  Admittedly I'm just testing at present with some set-track with 10.5" curves and a couple of points. Come over the points at speed and everybody dies! I also note the world needs to be very flat and stable.

In the planning stage at present with 8ft by 2ft 9" surface up in the loft; should be able to get nice long straights and reasonable curves with flexitrack.
Regarding points. Since I'm running passenger expresses to Glasgow, would you recommend the gentlest, widest radius turnouts and streamline rather than set-track?
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 15, 2017, 10:14:21 PM
Quote from: Old Crow on October 15, 2017, 10:10:20 PM
Since I'm running passenger expresses to Glasgow, would you recommend the gentlest, widest radius turnouts and streamline rather than set-track?

Simple answer from me is "Yes!"
Use the largest point on the scenic sections and small ones in the fiddle yard if you have one.
I use code 55 electrofrogs throughout. The small ones, being 12" radius curve, get used in the fiddle yard and branch line and large ones for the scenic main running ovals.
Title: Re: Light weight and traction issues.
Post by: daveg on October 15, 2017, 10:14:32 PM
Quote from: Old Crow on October 15, 2017, 10:10:20 PM

Regarding points. Since I'm running passenger expresses to Glasgow, would you recommend the gentlest, widest radius turnouts and streamline rather than set-track?

Most definitely!

Dave G
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 15, 2017, 10:35:11 PM
Quote from: Old Crow on October 15, 2017, 10:10:20 PM
Since I'm running passenger expresses to Glasgow, would you recommend the gentlest, widest radius turnouts and streamline rather than set-track?

Absolutely!

It's one of the basic "rules" of railway modelling: always use the widest curves and longest points that you can accommodate on your layout.  Trains will always run better.
Title: Re: Light weight and traction issues.
Post by: PLD on October 16, 2017, 07:51:57 AM
Quote from: njee20 on October 14, 2017, 09:28:08 AM
Quote from: PLD on October 14, 2017, 12:49:38 AM
If they're the ones I'm thinking of, the wheel profile is horrid with no transition from tread to flange... Adding weight may help, but as you say it's compensation for rather than addressing the root cause which isn't simply lack of weight...

Adding weight does help. That's a fact. The other option is to have them virtually unusable. The wheel size is a compromise for the scale. So it's not a fallacy at all. Pretty weird stance actually. I assume you take any weights out of stock to make them easier to haul?
No, I leave them as they are - don't add anything, don't subtract anything - what's so weird about that ?  :confused2: ::) :hmmm:

As YOU said and I AGREED with, it's compensating for and not addressing the root cause of poorly profiled wheels or badly laid track.
Quite weird that you call me weird for agreeing with you...  :doh:

I get the track right and replace wheels where necessary...
Title: Re: Light weight and traction issues.
Post by: njee20 on October 16, 2017, 08:39:19 AM
But it does resolve the symptom, so it's by no means a fallacy that adding weight helps. Which were your words.

There are also examples, like that I gave of the Megafrets, where the design is the cause,  more so than track laying. Even on other stock, adding weight is generally easier than relaying track or redesigning a layout.

As for removing weight, I just thought that if you think adding weight serves only to limit the hauling power, surely you'd try and make stock as light as possible? Some stock is much lighter than others as we've don't adopt NMRA guidelines, so it's weird to dismiss adding weight, yet fully accept the wild variations in stock weight. Didn't say you were weird, that's just a weird, and contradictory stance IMO.

Quote from: Old Crow on October 15, 2017, 10:10:20 PM
Regarding points. Since I'm running passenger expresses to Glasgow, would you recommend the gentlest, widest radius turnouts and streamline rather than set-track?

As others have said I think you should always go for the most gentle radius you can. Model points are vastly compressed, and even large radius are much tighter than anything you'd find on a main line in the UK.
Title: Re: Light weight and traction issues.
Post by: Dr Al on October 16, 2017, 01:19:51 PM
Quote from: PLD on October 16, 2017, 07:51:57 AM
No, I leave them as they are - don't add anything, don't subtract anything - what's so weird about that ?  :confused2: ::) :hmmm:

As YOU said and I AGREED with, it's compensating for and not addressing the root cause of poorly profiled wheels or badly laid track.
Quite weird that you call me weird for agreeing with you...  :doh:

I get the track right and replace wheels where necessary...

I would strongly agree with PLD - don't add weight to anything RTR - it's almost always a poor solution to any actual problem, usually rooted in the trackwork. Moreso, it just gives your locos harder work to do which isn't desirable for mechanisms and motors. Indeed, Farish when produced in England used to explicitly warn against this in their included guarantee cards.

Any time I get a piece of RTR stock secondhand with weight added that weight immediately gets removed and binned.

The only exceptions are plastic kitbuilt wagons or coaches which tend to be *very* light - but any weighting added is only to bring up to the weight of an equivalently sized RTR model.

Cheers,
Alan
Title: Re: Light weight and traction issues.
Post by: Delboy on October 16, 2017, 01:33:22 PM
Quote from Dr Al,
QuoteI would strongly agree with PLD - don't add weight to anything RTR - it's almost always a poor solution to any actual problem, usually rooted in the trackwork.
So what is your solution to my "non-trackwork routed" coupling problem with a brand new set of 3 x RTR Farish wagons that I mentioned earlier as I do not want to mess with the coupling springs as was suggested by DLP. Especially as I am told, in a later post by another forum member, that the DLP solution is not correct and would in fact result in stiffer springs.
Please advise.
Dennis.
Title: Re: Light weight and traction issues.
Post by: Dr Al on October 16, 2017, 01:36:54 PM
Quote from: Delboy on October 16, 2017, 01:33:22 PM
So what is your solution to my "non-trackwork routed" coupling problem with a brand new set of 3 x RTR Farish wagons that I mentioned earlier as I do not want to mess with the coupling springs as was suggested by DLP. Especially as I am told, in a later post by another forum member, that the DLP solution is not correct and would in fact result in stiffer springs.

If you're not willing to adjust coupler springs then that's hardly helpful, as cutting down their length to reduce their spring constant would be the obvious thing I'd first do....

Cheers,
Alan
Title: Re: Light weight and traction issues.
Post by: Dr Al on October 16, 2017, 01:37:27 PM
But you could replace the couplers with Peco Elsies, that don't have springs.

Cheers,
Alan
Title: Re: Light weight and traction issues.
Post by: Delboy on October 16, 2017, 01:45:31 PM
Thanks for the advice Dr Al,
It just seems sad that anyone should need to mess with fresh "out of the box" wagons in order for them to function properly.
Dennis.
Title: Re: Light weight and traction issues.
Post by: JanW on October 16, 2017, 02:55:23 PM
The answer to that is quiet simple: it's a matter of choice and the manufacturer made this choice for you.
If you just run the coaches behind the loco and watch the trains go by you will be very pleased with the couplings as they are. I suppose the majority of buyers will expect this behaviour.
When the spring tension is reduced the chance of unwanted uncoupling increases and the loco can loose its train on a bad track section.
Difficult coupling/shunting is not only the case with n gauge couplings but also with some close coupling systems in the larger scales.
It seems there is still no coulping system that fulfills the needs of all modellers.....

Jan
Title: Re: Light weight and traction issues.
Post by: Steven B on October 16, 2017, 03:47:16 PM
There's nothing wrong with light stock if the wheels and track-work are up to it:
https://www.youtube.com/watch?v=2cT4P4YBdrM (https://www.youtube.com/watch?v=2cT4P4YBdrM)

https://www.youtube.com/watch?v=hs57P-C2q_8 (https://www.youtube.com/watch?v=hs57P-C2q_8)

If you can't couple up to stock without it moving then I'd be looking at modifying the coupling (the spring modification already mentioned, or replacing it) rather than adding weight.


Steven B.


Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 16, 2017, 04:42:57 PM
In N gauge there have always been small light wagons that bounce away rather than couple up.   Attempts at solutions to the problem include different coupling systems, reducing the spring tension, adding weights, even adding drag to the axles. 

I always assumed Peco's "Elsie" (ELC = Easy Light-Lift Close coupling, or something like that?) was an attempt at avoiding the tension of a sprung coupling.   I quite liked them in my British N days back in the 70s and 80s.

Adding mass to the wagon so it has greater inertia might help in combination with reducing the spring tension.  With free-running wheelsets it will still roll fine and not strain the loco once under way, but it resists the initial "shove" and allows the coupling to raise and connect. 

Personally, I just steady the wagon with my uncoupling hook (aka dentist's probe) as I back the loco onto the train, but I accept that some don't like the "hand of God" intruding on the scene.
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 17, 2017, 12:55:00 PM
I seem to have opened a can or worms with the add weight or not issue. So here's another one! The one thing that's really out of scale is the couplings. Yes they do work ok but look huge. Now I'm a beginner so I apologise for what might seem heresy to you experienced guys but, I was wondering the following. My mainline express coaches are more or less going to remain as coupled sets. Has anyone experimented with chaining them together - ie using small modelling or jewellers chain to simulate scale couplings? Any one tried this, though I do wonder if the GF couplings do act to guide the following bogies? As for uncoupling - one would have to ask a 12mm man to get underneath and do it!
Thinking about it though - I guess the standard coupling do prevent the unsprung buffers coming into contact. Any thoughts?
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 17, 2017, 01:12:01 PM
I guess the simplistic answer is "Yes - they do look huge and obtrusive"
Between coaches the best bet is to use the shortest shank couplers without suffering buffer lock round curves/through pointwork. If you intend running a loco in one direction only then remove the coupler from one end (this may enable you to use the buffer detailing parts)
Title: Re: Light weight and traction issues.
Post by: Dr Al on October 17, 2017, 01:18:20 PM
Quote from: newportnobby on October 17, 2017, 01:12:01 PM
Between coaches the best bet is to use the shortest shank couplers without suffering buffer lock round curves/through pointwork.

Depending on the specific coach you don't need to worry about buffer lock - for example the new tool Mk1s and Mk2s have buffers that sit slightly back from the corridor connection, meaning you can take full advantage of close coupling with short shank couplers to close the corridors right up to corridors-touching. The close coupling mechanism on most new coaches, that people pay for, then actually gets used around curves, unlike with standard length couplers where it's barely used properly at all unless you are on crazy tight curves.

Most coaches will handle this, Mk1, Mk2, Dapol Mk3, buffered or non-buffered types, Dapol Gresley - though there are some exceptions, like the Farish Staniers whose buffers stand more prominently.

Personally closing up these gaps is far more noticable than the couplers in rakes IMHO - the couplers aren't greatly visible.

Cheers,
Alan
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 17, 2017, 01:52:34 PM
  @Old Crow (http://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=6360)  chain is a bad idea- it can't cope with propelling stock instead of pulling.  You'll get all sorts of buffer lock problems.

There are so many possible designs of coupling mechanism it's not always possible to come up with a single solution which works when mixing types.   For example, you have can NEM or T-shank couplings with various lengths of shaft; the coupling pocket may or may not be mounted on a KK close coupling mechanism which expands forward to increase the gap when the model is on a curve.


For newer stock with NEM pockets it is possible to buy straight forward coupling bars to permanently connect rakes together.

For older stock with T-shank coupling boxes, I've seen home-grown solutions such as cutting off the side and front of the Rapido hook and gluing two such butchered couplings together.  One side is then fitted into the box as normal, and on the other side the couplin box is left empty and open so that the T shank will just slip in for coupling up. works quite well.
Title: Re: Light weight and traction issues.
Post by: Dorsetmike on October 17, 2017, 02:01:15 PM
I've used pieces of suitably bent paper clip as permanent couplings on fixed rakes; admittedly on much older Farish stock, newer stock would need holes making in the bogies
Title: Re: Light weight and traction issues.
Post by: PLD on October 17, 2017, 02:16:07 PM
Within fixed rakes, a semi permanent coupling will be less prone to intended decoupling as well as allowing you to close up the gap but a rigid bar is better than a flexible chain especially on bogie vehicles. I use small staples which handily gives a consistent size as well as being easily obtainable.
Title: Re: Light weight and traction issues.
Post by: njee20 on October 17, 2017, 02:21:11 PM
You can get 3D printed t-shank bar couplings, here (https://www.shapeways.com/product/HGEZSCPU9/n-scale-11mm-fixed-coupling), he does a variety of lengths. Keep meaning to get some.

For NEMs I use these (https://www.shapeways.com/product/LE8R794DR/n-scale-nem-fixed-bar-couplings-3-5-5-7mm), which are excellent if you're able to leave rakes semi-permanently coupled.

Cavan Millward does some which look like brake pipes etc, but the cost is far higher, and IMO simple and unobtrusive is sufficient.

Obviously those don't help with stock moving when you attempt to couple it though, indeed quite the opposite!
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 17, 2017, 05:35:00 PM
Thanks for the thoughts; most appreciated by a newbie. Buffer lock! Yes, I must confess, I'd considered that as there's no way N scale buffers could act like real ones. The idea of a semi-rigid premanent coupling, as suggested from say a paper clip or similar might be worth an experiment in the future as might be cut down buffers?). For now I'll live with what I've got but the ones that really bug me are those on the front of tank engines; just look crude. 

Another issue? On corridor carriage sets, the coaches are rather far apart and with clear air between. I've seen that you can get minature corridor bellows made of folded paper. anyone had any experience with thse - seems they do warn you about tight curves so maybe they are too rigid?
Title: Re: Light weight and traction issues.
Post by: Dr Al on October 17, 2017, 05:56:16 PM
Quote from: Old Crow on October 17, 2017, 05:35:00 PM
Another issue? On corridor carriage sets, the coaches are rather far apart and with clear air between. I've seen that you can get minature corridor bellows made of folded paper. anyone had any experience with thse - seems they do warn you about tight curves so maybe they are too rigid?

As above - modern new coaches have close coupling mechanisms. Most folk don't use them to their fullest. Fitting short shank couplers can allow many of them to close the corridors right up to touching, while still negociating curves.

E.g.

Dapol Gresley:
(http://www.ngaugeforum.co.uk/SMFN/gallery/albums/Dr_Al's_models/Dir_4/main_33513.JPG)

Farish Mk2 (one short, one standard)
(http://www.ngaugeforum.co.uk/SMFN/gallery/albums/Dr_Al's_models/Dir_4/main_34161.jpg)

Dapol mk3 (using Dapol fixed knuckle couplings, that come in the box)
(http://www.ngaugeforum.co.uk/SMFN/gallery/albums/Dr_Al's_models/Dir_4/main_34162.jpg)

Farish Mk1 (one short, one standard)
(http://www.ngaugeforum.co.uk/SMFN/gallery/albums/Dr_Al's_models/Dir_3/main_32108.JPG)

Only for older coaches should you need some additional bellows, and most of those can also have their coupling distance shortened to make the coach to coach distance more realistic.

e.g.

Farish Mk4s, before:
(http://www.ngaugeforum.co.uk/SMFN/gallery/albums/Dr_Al's_models/Dir_3/main_32302.jpg)

Farish Mk4s with short shank sprung couplers.
(http://www.ngaugeforum.co.uk/SMFN/gallery/albums/Dr_Al's_models/Dir_3/main_32301.jpg)

All of the above go round curves down to 12" fine and will do tighter (tho I don't have tighter on my layout)

Cheers,
Alan
Title: Re: Light weight and traction issues.
Post by: ntpntpntp on October 17, 2017, 06:36:10 PM
Quote from: Old Crow on October 17, 2017, 05:35:00 PM
...worth an experiment in the future .. might be cut down buffers

I would suggest avoid butchering your models if you can.  It really annoys me when I find a second hand coach or wagon I want and someone's cut the buffer(s) off!   It's really not necessary and ruins the look IMO.
Title: Re: Light weight and traction issues.
Post by: Old Crow on October 18, 2017, 02:26:29 AM
So! where can I get these short couplings?
Title: Re: Light weight and traction issues.
Post by: johnlambert on October 18, 2017, 08:04:30 AM
Graham Farish sells short-shank NEM couplings in packs of 20 as an accessory, 379-402.  Available from all the usual outlets.  I think the pack is under £10.

Dapol supplies the short dummy knuckle couplings in the accessory bag with any model that comes with NEM pockets.  They were also available as an accessory but I don't know if that's still the case.
Title: Re: Light weight and traction issues.
Post by: Newportnobby on October 18, 2017, 09:24:17 AM
Dapol short easi shunts are available in a pack - 2A-000-011
Title: Re: Light weight and traction issues.
Post by: Webbo on October 18, 2017, 09:40:34 AM
I have a rake of Farish MK1 coaches of recent manufacture (Blue Riband). A short shank and a regular coupling together provide for close coupling between coaches so that the diaphragms are pretty close on the straights. I have 18" curves which my train can negotiate just fine without buffer or diaphragm locking problems. The visual effect is very good without having to add bellows. I don't think that two short shank couplers would work together even on straight track. The downside with mucking about with shank lengths is that things only work if there is a short shank on one side and a regular shank on the other. It's just too bad that Farish doesn't manufacture a shank length intermediate between short and regular so all coaches would couple closely no matter which way round they were or in what order.

Webbo
Title: Re: Light weight and traction issues.
Post by: Bealman on October 18, 2017, 09:49:17 AM
A good observation by our man in Canberra, and one with which I totally agree  :thumbsup:
Title: Re: Light weight and traction issues.
Post by: njee20 on October 18, 2017, 10:50:28 AM
I also use one regular and one short shank dummy knuckle from the Dapol offerings, haven't tried Easi-shunt, but I find that works down to about 11" curves. Looking at how close the gangways are on those mk2s on the previous page I'm amazed they go round corners at all!