Light weight and traction issues.

Started by Old Crow, October 10, 2017, 04:27:08 PM

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ntpntpntp

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.
Nick.   2021 celebrating the 25th anniversary of "Königshafen" exhibition layout!
https://www.ngaugeforum.co.uk/SMFN/index.php?topic=50050.0

Old Crow

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?

Newportnobby

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)

Dr Al

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
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

"We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces."Dr. Carl Sagan

ntpntpntp

  @Old Crow  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.
Nick.   2021 celebrating the 25th anniversary of "Königshafen" exhibition layout!
https://www.ngaugeforum.co.uk/SMFN/index.php?topic=50050.0

Dorsetmike

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
Cheers MIKE
[smg id=6583]


How many roads must a man walk down ... ... ... ... ... before he knows he's lost!

PLD

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.

njee20

You can get 3D printed t-shank bar couplings, here, he does a variety of lengths. Keep meaning to get some.

For NEMs I use these, 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!

Old Crow

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?

Dr Al

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:


Farish Mk2 (one short, one standard)


Dapol mk3 (using Dapol fixed knuckle couplings, that come in the box)


Farish Mk1 (one short, one standard)


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:


Farish Mk4s with short shank sprung couplers.


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
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

"We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces."Dr. Carl Sagan

ntpntpntp

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.
Nick.   2021 celebrating the 25th anniversary of "Königshafen" exhibition layout!
https://www.ngaugeforum.co.uk/SMFN/index.php?topic=50050.0

Old Crow

So! where can I get these short couplings?

johnlambert

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.


Webbo

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

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