AJ Couplings and Coach Bogies

Help and advice for those starting in, or converting to P4 standards. A place to share modelling as a beginner in P4.
Brinkly
Posts: 195
Joined: Sat Nov 29, 2008 12:13 pm

AJ Couplings and Coach Bogies

Postby Brinkly » Sun Jun 04, 2023 2:00 pm

Dear all,

I’m currently converting a selection of RTR coaches to P4, using a mixture of Bill Bedford, Masokits and Brass Master coach bogies.

Out of interest, how do other members who use AJs fit them to coach bogies? I’d be very grateful to see some working practices! If you could share a photo, or two, and a description of what you have done I would be most grateful!

Best wishes,

Nick.

davebradwell
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Joined: Fri Jan 18, 2019 3:48 pm

Re: AJ Couplings and Coach Bogies

Postby davebradwell » Sun Jun 04, 2023 8:30 pm

As with all queries relating to these couplings, you should refer to Chris Pendlenton's work in MRJ 223. Essentially there is a pulling post just ahead of the centre pivot - this position avoids the yawing of the bogie that results from a fixing to the rear stretcher but minimises the influence on the bogie tracking from side forces on the coupling.

If you refer to his article in MRJ 200, you might decide to save yourself the expense of brass bogies, although perhaps I'm just feeling slighted at being missed out of your list. Suppose Justin isn't there either so I'm in good company.

DaveB

Terry Bendall
Forum Team
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Re: AJ Couplings and Coach Bogies

Postby Terry Bendall » Mon Jun 05, 2023 8:17 am

Brinkly wrote: I’d be very grateful to see some working practices! If you could share a photo, or two, and a description of what you have done I would be most grateful!


Alternatively get hold of the book published by the Society and still available from the stores.

Terry Bendall

bécasse
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Joined: Sun Jun 17, 2018 8:26 am

Re: AJ Couplings and Coach Bogies

Postby bécasse » Mon Jun 05, 2023 9:17 am

I would say that if you are using AJ couplings the book is indispensable. I started using them 50+ years ago with only magazine articles for guidance and had to learn a lot "on the hoof", although they worked well even through very long (50+ hours) exhibitions. The book, which effectively emanates from the MMRS "home" of AJs, provides information on just about everything that you need or might need to know.

The only thing that I could add is that, if you use electromagnetic uncouplers powered from the mains via a transformer/rectifier set up, you might find that one or two uncouplers are exactly the right length to establish resonance with the uncoupler. It happened on one of ours and crimping a fishing line "lead" weight to the coupling stalk towards its fixed end cured the problem instantly. It's almost certainly a rare problem as otherwise I am sure that Dave Booth would have mentioned it in the book.

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Julian Roberts
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Re: AJ Couplings and Coach Bogies

Postby Julian Roberts » Mon Jun 05, 2023 1:53 pm

This is likely a very naff set up, compared with Chris Pendlenton standards! Here is my easily demounted bogie type - dress type popper fixing to coach body. So I can easily take a photo for you, this may not be very helpful as it's my unconventional modification to the normal torsion bar way this type of bogie is assembled. I described it in Snooze 201, I think it was. The bogies and couplings have performed fine at several shows over the last ten years or so since they were made.

Despite appearances the AJ is only soldered in two places, to the furthest two wires from the hook.

I found the problem with fixing an AJ to coach bogies is that it's no use using the jig that clamps onto the buffers as the bogie can flop all over the place. I can't exactly remember how I did get the coupling in the right place - probably soldered it approximately and then bent it around till it met the buffer and coupling height gauge that sits on the track.

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davebradwell
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Re: AJ Couplings and Coach Bogies

Postby davebradwell » Mon Jun 05, 2023 2:30 pm

You're guilty of putting joggles in the coupling wire, Julian. I've seen worse, it's true but best be careful. When you have a few coaches coupled together, these introduce a springiness which allows the buffers to move further apart and can make the rear of the train bounce as it travels. Coupling must be straight from whatever takes the pull right to the head. If you put a pulling post just in front of the spacer then up to this point the wire can do whatever it likes to be the right length but then run straight to the end. Suspect yours might be a bit short for reliable uncoupling unless you have mega-magnets.

DaveB

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Julian Roberts
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Re: AJ Couplings and Coach Bogies

Postby Julian Roberts » Mon Jun 05, 2023 3:37 pm

Aha Dave, thanks for that advice, I knew there is plenty of imperfection! Trains have been max 2 or so coaches so the issues of "proper" train lengths don't arise, yes I'm sure there are many considerations with longer ones. The uncoupler is useless, I go in for the hoops of soft iron now.

davebradwell
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Joined: Fri Jan 18, 2019 3:48 pm

Re: AJ Couplings and Coach Bogies

Postby davebradwell » Mon Jun 05, 2023 7:56 pm

I've seen them with right-angled joggles and it doesn't take many coaches to get them going, Julian. Best to always play safe - you never know when your stock might end up in a silly session as part of a 20 coach train, somewhere.

Reminder to Brinkly - it isn't just about the couplings, there's gangways and buffers in there too.

DaveB

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Paul Townsend
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Re: AJ Couplings and Coach Bogies

Postby Paul Townsend » Thu Aug 17, 2023 6:56 am

Not just about AJs on bogies......

My developing model of Broad Gauge Dartmouth in 1870s is being worked up to an operatiobnal state in preparation for exhibiting at RailWells in August 2024.

My job is primarily the layout as 3 kind friends are lending locos and rolling stock.I have some of those on long term loan so they are used for track testing etc.

There is an operational issue with couplings in that the lovely models are built to prototype accuracy which means that anything pre_Dean, say 1865, has microscopic cast hooks and should use free chains with open hooks at each end. These look good but are totally impractible for operational work, especially as tiny linked safety chains should also be used.

The owner has given me permission to improve matters and I have decided to fit AJs partly because I have used them before on Highbridge S&DJR, locos and 4 wheel waggons, no coaches.

The immediate need is for me to fit them to half a dozen 6 wheel vehicles, carriages and luggage and freight vehicles.
I have no experience of anything bigger than 12ton waggons.

Are there any particular tips that more experienced users can share?

Later I will do a few bogie vehicles but locos first. In theory the latter should get Nigel Cliffe's on board uncouplers but for the next year all is DC only, DCC is scheduled for late 2024


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