In search of a cheap automatic coupling

[BryanW]

I am relatively new to garden railway modelling having been (and still involved in) S4 for over 40 years. A chance purchase of a "complete garden railway train set" last year and its building - at least to a basic oval - this year has opened up a new and exciting world. That is apart from one thing - couplings, or rather the apparent absence of any that couple and uncouple automatically. With my S4 model I am used to having stock couple and uncouple using Alex Jackson couplings (not the easiest to set up but wonderful when they do work) and it was a surprise therefore to find that in a scale that is four times the size there wasn't something that "just worked". The stock I have came with the seemingly ubiquitous hook and chain and most other layouts I have seen and visited use the same. I like to do some shunting and have never got on with shunters poles and hands from the sky. I am therefore on the look out for something that looks reasonably prototypical but above all works reliably. I have dabbled with the Peckforton couplings described by Rik of this parish in his blog and although I have got them to work I find the phosphor bronze spring hook is too strong and the stock needs a good shove to get them to couple. Clearly they work for Rik but it may be that his stock is heavier, being on 45mm track rather than 32mm that stops then careering down the rails. I would continue to experiment with these using thinner wire for the coupling hooks, or maybe putting in several spring turns where the wire leaves the brass bracket but ultimately these couplings do not satisfy my wish to have automatic uncoupling.
The one I have seen recently, although the video showing them is some years old, is on the Hambleden Valley Railway by Steve Howard. The You Tube Videos of this show shunting operations being carried out by live steam locos running slowly (with SloMo devices fitted) and TenMille chopper couplings which seem to have been adapted to have an extra "leg" with a small neodymium magnet attached. This is operated (magnetically attracted) to a larger magnet in the track bed when the stock is not under tension. I have tried to find more details of this system - which performs very well and would suit my needs - but have failed. I do note that the stock is "handed" with a hook only on one end. As I do not have any return loops or turntable this does not present a problem for me.
So, and with apologies for the length of this post, my questions. Does anyone know the details of the modification? Are Tenmille the only chopper couplings out there suitable for this modification? Will they (reliably) couple with other chopper couplings (eg Swift Sixteen, Accucraft, Slaters etc)? I realise these couplings are not cheap (£10 plus per pair seems to be the going rate) and with over 20 items of stock to "convert" I don't want to invest over £200 on something that may not perform satisfactorily.
Many thanks in anticipation of your replies.

Bryan

[philipy]

Hi Bryan,
I can't answer your basic question about a write up of that specific layout/coupling system. However what I can say is that the subject does crop up from time to time on here and individuals ( including me) have a play at trying to achieve reliable Alex Jackson type operations. As far as I know, only Rik and a former member, Tom-Tom-Go, have come close, but to my knowledge there are no commercially available systems even from Cottage Industry suppliers apart from the versions fitted by some big continental train manufacturers but which I know nothing about.

I think a large part of the problem has to do with wheel and track standards. Th fine tolerances of P4/S4 allow for accurate positioning of the 10thou Alex Jackson wire which even then can be a *%$@#~ to set up. In 32/45, the standards are so much looser and curves, wheelbases and overhangs, so much more variable, that it simply doesn't work for most of us.

[ge_rik]

Hi Bryan
Welcome to the forum and to garden railways. You're right, my couplings usually do require an extra shove unless, as you say, there are a few wagons providing some extra resistance. Interestingly, I sometimes experience an additional Alex Jackson effect if one or both hooks are slightly out of the vertical. That can actually be a bit annoying if I think I've uncoupled them.

I did toy with the idea of choppers for a while but the cost of re-equipping around 90 vehicles sent me down my cheapo hook and loop system. Plus, being compatible with my existing LGB style couplings meant I could instal them piecemeal over time.

They aren't perfect. They can easily be bent out of alignment, which means they require tweaking from time to time and, of course, they ain't exactly prototypical. But they do the job and they are cheap.

Rik

[BryanW]

Thank you Philip and Rik for your comments and advice. On reflection I can only agree with Philip about the more exacting standards of S4 modelling when judged against the relative "sloppiness" of SM32. Although most of my curves are set at 5 feet I do have one that reduces to 4 feet and I can see problems in getting chopper couplings to work with a high degree of reliability in these circumstances. I have therefore dismissed that idea and gone back to working on Rik's solution.
First of all, because I felt the coupling action was too "harsh" , I substituted the phosphor bronze hook with a thinner wire of sprung steel as here

PXL_20260920_135355945.jpg (1.24 MiB) Viewed 84 times

I wasn't happy with the result (still making the wagons bounce down the track rather than couple up) so went back to the phosphor bronze spring but added a double loop - thereby making it longer. There was a small improvement but not significantly so. See here

PXL_20260920_135409724.jpg (1.22 MiB) Viewed 84 times

Finally, and having remembered how Sprat and Winkle couplings work I made the hook pivot rather than use a fixed point. Rather than start from scratch , having made about six of Rik's brackets with attached bars, I soldered the hook to a short stretch of brass tube which has a length of 2mm brass rod running through, the ends of which are soldered to the angle of the bar. I soldered a simple piece of brass behind the pivot to make a counterweight. Hopefully all this is shown in the attached photo.

PXL_20260920_174631510.jpg (1.26 MiB) Viewed 84 times

I have taken another photograph of this from the side (but have run out of space in this post to include it) and have recorded two short videos of the "before and after" differences which, when and if I work out how to do it will attempt to post on here.
In short however the pivotted version of "Rik's hook" now works without the stock having to crash into one another. The short length of nail that is soldered to the hook in the last photo is to form the dropper to be attracted by a magnet to be placed in the track but as yet I haven't advanced that part of this conundrum. I still need to do more work to arrive at the "ideal" set of dimensions etc. for SM32. The trick is to make the hook so that the paddle side is just heavy enough to hold the hook in the elevated or upper position but needs little sliding resistance to make it slide down and behind the bar. I have also found that using fine emery paper on the sliding surface of the hook substantially assists a smooth coupling action.
My thanks to Rik in particular for providing the initial ideas and inspiration to carry out this experiment. I will post further if all continues to work reliably.
Bryan

[BryanW]

Here is the final photograph showing the pivoted hook from the side

PXL_20260920_174732342.jpg (1.12 MiB) Viewed 83 times

[BryanW]

Firstly, I have retitled this thread "In search of a cheap automatic coupling" since the original title "Chopper Couplings" was no longer relevant.
Secondly I have managed to upload the two videos of before and after mentioned above onto YouTube and will attempt below to provide a link to them. Here is the first one with the sprung type of hook:



and here's the second one with the hook on a pivot:



I hope these work!

Bryan