Dodgy Couplings

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New2N
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Joined: Fri Nov 20, 2020 8:02 pm

Re: Dodgy Couplings

Postby New2N » Sun Jan 10, 2021 6:23 pm

[quote=

Lacking that answer, then pragmatically, I would suggest that you inspect all your stock for coupler height, and either go for the average (arithmetic mean) height, and reset as required, or select the most frequently occurring height that works really well and reset as required. The latter may well be least work.[/quote]

I have inspected the couplers and I know which ones are low, the ones on the locos. How do I reset them? You make it sound as though it is simple.
They are all the NEM pocket type.

New2N
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Joined: Fri Nov 20, 2020 8:02 pm

Re: Dodgy Couplings

Postby New2N » Sun Jan 10, 2021 6:27 pm

Mike Parkes wrote:Being relatively recent models that you are talking about I would take it that the couplings are of the clip in place into a mount type allowing other types of couplings to be readily fitted - now it might be there is some slop in the fitment which is causing some couplings to drop below normal height;
certainly this can be an issue in OO and the solution there is to slip a thin piece of suitable material in the mount underneath the coupling to support it at around the correct height. Maybe something similar is needed. If some couplings look slightly too high then it could be they are at the other end of tolerances and it would be worth trying swopping the over high coupling with an under height coupling.


Thanks for your suggestion. They are indeed NEM pocket devices and I had thought about packing them appropriately, I just wondered if there was a more 'professional' solution.

Bigmet
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Joined: Tue Aug 14, 2007 2:19 pm

Re: Dodgy Couplings

Postby Bigmet » Sun Jan 10, 2021 8:25 pm

New2N wrote:...I have inspected the couplers and I know which ones are low, the ones on the locos. How do I reset them? You make it sound as though it is simple. They are all the NEM pocket type.

Much as Mike Parkes has already suggested, you need to look closely at whether the coupler pockets are properly located, see if there is room to insert some thin packing (a 'shim') in the pocket to raise the coupler, look at the locator on the coupler to see if some are out of position, and there may be more possibilities. In OO pockets can be turned over to use a veritcal assymetry in the moulding to alter coupler height, and the mounting on the vehicle can be cut into to allow the pocket mounting to rise, and the locator on the coupler can be filed, so that thicker packing can be used to move it up or down. Not having looked at N with coupler pockets, it's not something for which I can offer proven ideas for N unfortunately.

New2N
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Joined: Fri Nov 20, 2020 8:02 pm

Re: Dodgy Couplings

Postby New2N » Sun Jan 10, 2021 8:58 pm

Bigmet wrote:
New2N wrote:...I have inspected the couplers and I know which ones are low, the ones on the locos. How do I reset them? You make it sound as though it is simple. They are all the NEM pocket type.

Much as Mike Parkes has already suggested, you need to look closely at whether the coupler pockets are properly located, see if there is room to insert some thin packing (a 'shim') in the pocket to raise the coupler, look at the locator on the coupler to see if some are out of position, and there may be more possibilities. In OO pockets can be turned over to use a veritcal assymetry in the moulding to alter coupler height, and the mounting on the vehicle can be cut into to allow the pocket mounting to rise, and the locator on the coupler can be filed, so that thicker packing can be used to move it up or down. Not having looked at N with coupler pockets, it's not something for which I can offer proven ideas for N unfortunately.


I am fast learning that N is a far more difficult and problematical scale than OO. The N gauge pockets are so tiny that I am struggling to find anything fine enough to 'shim' the coupling box. I have instead applied a spot of tacky glue to the adjusted coupling and will see how that works tomorrow.

If that does not work I will make a permanent rod type coupling or superglue the existing couplings as I cannot see me shunting or separating these trucks and locos.

What I have difficulty in understanding is that you can buy new wagons and a new loco, from the same manufacturer, which just do not couple up properly.

Bigmet
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Joined: Tue Aug 14, 2007 2:19 pm

Re: Dodgy Couplings

Postby Bigmet » Mon Jan 11, 2021 10:06 am

New2N wrote:...I am fast learning that N is a far more difficult and problematical scale than OO. The N gauge pockets are so tiny that I am struggling to find anything fine enough to 'shim' the coupling box. I have instead applied a spot of tacky glue to the adjusted coupling and will see how that works tomorrow...

Yes, the small size is one of those aspects you have to learn how to work around by your own experiment, and learning from other's experience and advice.

I think you might do well to post in the N gauge section with a title like 'Coupler height adjustment' as none of the N gauge users on this site appear to have spotted this thread, and they will hopefully have good experience to share.

New2N wrote:...What I have difficulty in understanding is that you can buy new wagons and a new loco, from the same manufacturer, which just do not couple up properly.

The 'reasons why' can be many and varied, ranging from constraints on the coupler mounting position caused by the prototype design, manufacturing limitations, simple error in design that wasn't detected before production tooling was cut, and even possibly lack of awareness of the correct position.

In my opinion this problem should be brought to the retailer's attention, as an aspect of the product that the manufacturer needs to get right.

Byegad
Posts: 140
Joined: Fri Jun 30, 2017 1:56 pm

Re: Dodgy Couplings

Postby Byegad » Mon Jan 11, 2021 10:25 am

Bigmet wrote:
New2N wrote:...Is there a simple solution to this problem.

Simplest? Return to OO!

It is very simple indeed, N demands considerably more care and developed skill in the matter of stable baseboards, tracklaying and optimisation of the set up of locos and stock to achieve equivalent results to OO in running reliability. If you can patiently work at that, very good results can be yours. I for one don't possess the patience, because I can practically throw together OO (RTR and hand built from kits and scratch) with great reliability, and just cannot do this in N gauge. But, YMMV, and you can only find this out by trying. All the best with it!


At exhibitions, remember them? I often see 00 layouts with quite ropey track, in that the joints show a scale 3-6" gap, and a similar difference in rail height at the join. The standard 00 coupler, which as a Hornby Dublo* child I always think of as the Triang one, with a loop and hook arrangement, seems to be very forgiving.

In N some basic care to get the joints pays dividends and the judicious use of a mini grinder or file to get level joints makes decoupling a rare event, easily avoided by checking/adjusting coupler height and a dab of Tacky Wax, usually for Peco wagons where there's no spring effect to avoid one coupling jumping up, say on a point and leaving the rest of the train go off.

*H-D used a metal, later plastic, coupling more like the N gauge standard 'Rapido' which worked fine on my boyhood trainset.

Bigmet
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Joined: Tue Aug 14, 2007 2:19 pm

Re: Dodgy Couplings

Postby Bigmet » Mon Jan 11, 2021 12:20 pm

Byegad wrote:...At exhibitions, remember them? I often see 00 layouts with quite ropey track, in that the joints show a scale 3-6" gap, and a similar difference in rail height at the join. The standard 00 coupler, which as a Hornby Dublo* child I always think of as the Triang one, with a loop and hook arrangement, seems to be very forgiving...

You are not wrong! This 'crash along' characteristic in OO is pretty much 'locked in' as the standard which RTR OO product must tolerate, by the standard set track point, which has a ruddy great 'hole' at the point crossing among its several unlovely characteristics.

The only RTR OO manufacturer with a significant range that ignores this requirement is Heljan, employing a narrower tyre and much finer flange on their loco wheels much to the advantage of their model's appearance. Now, this does occasion some comment about 'track sensitivity' of their product, but there's no overwhelming negative feedback (it's fine on Peco streamline and equivalent). This may change with wider distribution of some Heljan items via the EFE brand marketing, wait and see on that one.

Although the 'tension lock' is pretty tolerant of poor track, it is nowhere compared to the continental HO 'hook and loop' coupler. The best examples of this design will remain coupled over vertical movements far greater than the stock can tolerate, without constraining that movement at any point before the wheels come off the rail of their own accord.

Byegad wrote:...H-D used a metal, later plastic, coupling more like the N gauge standard 'Rapido' which worked fine on my boyhood trainset.

Which was of course the 'Peco Simplex', H-D paying a licence fee for its use, and all these years later Peco still sell it in the superior original metal form. It's something of a shame that Peco never progressed development of this coupling principle; Kadee introducing the modern equivalent, a working representation of the prototype knuckle coupler, and have gone on to achieve 'world domination' in this coupler design...

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Ironduke
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Re: Dodgy Couplings

Postby Ironduke » Mon Jan 11, 2021 10:29 pm

the N scale NEM pocket is very different to the HO/OO version. there is certainly no room for shims. It seems the coupler is retained in the socket with nubbs either side, which double as the pivot that the Rapido coupler levers up from.

I model n scale American trains, which don't use anything like the NEM socket, so the only advice I can offer is, make sure none of the Rapido uncoupler pins hang lower than the track surface. If they hit anything like a point blade or level crossing they may flip up or snag which can cause upcoupling and derailments. With the Amercian knuckle style couplers you can bend the trip pin upwards to avoid this. I suppose with Rapidos you'd have to cut the pin?

Photos would definitely help here. I would like to see how much higher or lower the couplers actually are.
Regards
Rob

Bigmet
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Joined: Tue Aug 14, 2007 2:19 pm

Re: Dodgy Couplings

Postby Bigmet » Tue Jan 12, 2021 10:16 am

Ironduke wrote:the N scale NEM pocket is very different to the HO/OO version. there is certainly no room for shims. It seems the coupler is retained in the socket with nubbs either side, which double as the pivot that the Rapido coupler levers up from...

That's helpful to know, because it rules out the shimming into the the pocket that one can do on the HO (OO) NEM coupler pocket. Which is a bind, but nothing can be done about it.


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