Dingham Couplings - Yet more posts.

[Penlan]

There have been numerous topics on Dingham Couplings in the past.

 

My etchings arrived today.

First, the instructions mention there's a change in the instructions re. the magnetic dropper.
'Make a dropper from the 0.45mm soft iron wire' - the illustration shows a loop at the top and one strand, 10mm long, hanging down.  The wire supplied is 0.35mm ?

However in the web site instructions at http://www.dingham.co.uk/4mm_inst.htm illustrates the dropper wire as approx., 22mm long, looped through a hole on the hook etching to achieve a (doubled) 10mm drop - I suspect the 22mm length of soft iron wire, may not have allowed the loop to drop down proprely through it's own weight.

I have some 0.45mm soft iron wire, so I shall try it as a single dropper - it's a load I had from old PC Models stock at one time - Us old timers never throw anything away, trouble is finding it.

 

I noticed in one of the many Topic post's that the former 0.35mm wire had been twisted and soldered, I should imagine this was a bit weighty, bearing in mind the 'hook' in front of the pivot HAS to be heavier than any weight behind it, in order to function properly.

 

Another revision noted is that on the website, Dingham's mention that the simple loop latch type 1, is better than the paddle type 2, whereas the instruction's received today state the other way round.  I wonder if that is user feedback, I shall be using Type 1.

 

In the topic at >>> http://www.rmweb.co.uk/community/index.php?/blog/483/entry-12435-dinghams-modified-now-more-realistic/  They are trying to add a 3 link coupling to act as a dropper to the loop, yet realising it can't come very far forward - to cosmetically appear as per a normal 3 link hanging down from a normal coupling hook - it would not act 'Dingham properly' however close to the loop pivot it is without some mighty magnetic pull - Everything's about balance, over centre weight etc., etc., 
If they drill a hole in the latch coupling hook, under the latch pivot, a standard 3 link coupling can be added for cosmetic purposes - If the concern is to make it look 'prototypical', then having a long top loop so it clears the front of the Dingham hook to couple up to other stock, that would seem to defeat the cosmetic mod.

 

Although the Dingham web site says the couplings can be used on curved track 3' and under, I have to admit I am not surprised people are having problems on some curves down to 2' radius. 

My minimum radius is 3' 3", I do have a couple of cross overs so I shall be looking at the best way to attach the couplings on 50' bogie coaches - any longer coaches are within set formations that have their own coupling system as per post #6 at http://www.rmweb.co.uk/community/index.php?/topic/10792-fixed-rake-couplings/

 

I shall now go away and assemble some couplings and report later.
One concern may be the clearances for the loop etc., under corridor connections, I shall have a look.
West Kirby Town did some mods in 7mm, so there may be a clue there, post #1623  http://www.rmweb.co.uk/community/index.php?/topic/54751-west-kirby-town-dingham-autocouplings-being-tested/page-65  almost bottom of page.

 

The reason I'm trying Dinghams? Well it's for shunting (dedicated) stock in the goods yard, adding, or taking off milk vans, etc., on through trains, and some colliery wagons collection, setting down manoeuvres, the rest of the layout will be a roundy-roundy - when I get time.
I don't envisage stock suddenly being the wrong way round for a shunting move.
 

BUT, should anybody have recent experiences, do let us know.

 

Thank you

Edited June 14, 2017 by Penlan

[Penlan]

And the first thing that occurs to me, from other peoples experience,

is they say the coupling loop is not laterally flexible enough.

 

Basically these couplings are acting like 3 or screw links, when pushing, the couplings are not involved in the action, it's the buffers, the Dingham loop has a width of 5mm, prototype wagon buffers are normally 1' 1" wide, lets say 4.5mm in 4mm scale to give some latitude.  If you needed the full 5mm width for a shunting action, there would be buffer locking anyway.

 

Perhaps it's on the bogie coaches the problem lies due to small radii, but attached to the bogies, they shouldn't present that much of a problem, apart from a bit of adaption to fit the hooks to the bogies and still appear to be near where they should be on the buffer face.  

But that's modelling as a hobby.

Edited June 14, 2017 by Penlan

[Junctionmad]

It's a bit more complex then that

 

Dinghams are designed to sit on the buffer beam, placing them on bogies means the coupling is far too low and you end up with a non standard solution , the problem is actually more acute with bogie freight stock as it nearly impossible to fix the dinghams so that they can couple to 2 axle stock

 

The coupling seems to be orientated to 2 axle freight stock only

 

What's surprising is the lack of used discussion on these couplings , it's as if very few people are using them in anger

Edited June 14, 2017 by Junctionmad

[Penlan]

Dinghams are designed to sit on the buffer beam, placing them on bogies means the coupling is far too low and you end up with a non standard solution , the problem is actually more acute with bogie freight stock as it nearly impossible to fix the dinghams so that they can couple to 2 axle stock

I'm just off out, visiting Exeter, back about 2am in the morning - so I can't resolve it this evening or do some sketches, but I thought a fixing on the bogie, such that a piece of metal comes to the end of the coach under the buffer beam, turned up and mates with the hook part of the coupling so it swings across the face of the buffer beam - thus I've chopped off the bit that's threaded through the buffer beam.  

On layouts with a reasonable radius curve there shouldn't be that much swing - but I will soon know

 

The problem is the difference between those who model with shall we say reasonable curves and those who use RTR track with it's small radii.   Dingham seem to suggesting all modellers can use their system, I don't think that is so.

 

Re. lack of input from user's, I shall be there, soon.

[davknigh]

I've been using them "in anger" for more than 15 years now and have never regretted making the change from 3 link/screw link. They are not perfect, little in this life is, but for shunting they work a treat with all the advantages of Kadees and much better appearance especially on steam era wagons.

 

In response to the OP, for the dropper I use a 20 mm length of whatever came in the package doubled over and passed through the loop with a twist so it swings freely and won't fall out 'cos it's quick and easy. I used both latches for a while but found the loop variety were too much of a faff for forming and filling plus using the paddle allows you to set up all your hooks in the same fashion with very little trade off in appearance. Passenger stock with corridors just needs tweaking to get the hook at the right level and care with set up pays off. There are a few instances where problems arise especially with wagons of greatly varying length on curves where the short wagon sometimes gets derailed. With locomotives with a lot of overhang the same thing can happen. A possible solution was posed in another thread which involved widening the lifting loop to 7mm which should work but I've not got around to trying it yet.

 

I like them. They look infinitely better than tension lock, they go where couplings belong- on the buffer beam, and they allow you to remotely drop wagons or pick them up as the situation demands.

 

Usual disclaimer applies.

 

Cheers,

 

David

 

Edited for clarity (I hope)

Edited June 14, 2017 by davknigh

[BG John]

I've got the 7mm ones to try, but they're still on my to-do list. It's a bit off-putting when the instructions of an established product pretty much say you're on your own when it comes to fitting them to bogie stock though! Almost all my stock will be 4-wheelers, with short wheelbase wagons, and 4-wheel coaches, but I've got a couple of non corridor bogie coaches to fit them to, although I've no idea how.

[davknigh]

I've got the 7mm ones to try, but they're still on my to-do list. It's a bit off-putting when the instructions of an established product pretty much say you're on your own when it comes to fitting them to bogie stock though! Almost all my stock will be 4-wheelers, with short wheelbase wagons, and 4-wheel coaches, but I've got a couple of non corridor bogie coaches to fit them to, although I've no idea how.

It depends. If you have seriously tight curves that would not accommodate regular screw link couplings mounted as per usual then the Dinghams probably won't work but I've mounted Dinghams on my bogies coaches in 4mm with no problem both running and propelling through a number 6 turnout. If the bogies are close to the end of the coach and perhaps if you have sprung buffers as well they're worth a try.

 

HTH

 

David

[Torper]

I use Dinghams on my layout where most of the points, at least on the main running lines, are B7s.  There can sometimes be problems with long wheelbased stock on one particular crossover and when that happens i wish that the loops were a lttle wider - I'll mabye try bodging some up accordingly but as i'm currently relaying the crossover with larger radius points that may not be necessary.  On gangwayed RTR passenger stock I've had to cut a small section out of the fairly thick bottom of the corridor connection just above the coupling (which is fixed as usual in the bufferbeam) and replace it with a thin piece of plasticard - that gives sufficient room for the couplings to work.  I do just the same as David does with the droppers.

 

Dinghams are not perfect; they're fairly fiddly to construct and they have to be set up pretty precisely if they're to work properly.  I've made a jig to do that - the instructions are by J. Offord and I've found it invaluable.  Unfortunately I can find no trace of it on the internet - PM me if you want a copy.

 

As I say, they're not perfect but they're far and away the least obtrusive of all autocouplers (at least for UK stock), they're very reasonably priced, and they work.

[BG John]

Wandering slightly off topic, does everyone use electromagnets to operate them? It seems they are necessary, but are the main problem for me with using them. The layout I'll be using them on will hopefully be totally radio controlled, with just a few wires to point servos, apart from whatever the electromagnets need. The baseboards will be internal doors, and I'm not too keen on making holes in them.

[davknigh]

Wandering slightly off topic, does everyone use electromagnets to operate them? It seems they are necessary, but are the main problem for me with using them. The layout I'll be using them on will hopefully be totally radio controlled, with just a few wires to point servos, apart from whatever the electromagnets need. The baseboards will be internal doors, and I'm not too keen on making holes in them.

I've tried electromagnets, button magnets and an old crochet hook and all work equally well. For the electromagnets I salvaged the coils from some ancient point motors and, IIRC, there is a plan for one on the Dingham website. I power the electromagnet from an old power pack set for about (I've never actually measured it) 6VDC, too much power results in a violent bounce in the lifting loop that can sometimes jam it in place. Button magnets work a little too well but I have heard of some who raise and lower the magnet as needed which seems to help. The crochet hook is used to flip the lifting loop up and has the advantage that you can uncouple anywhere but does involve the dreaded H o G which some consider blasphemy.

 

Cheers,

 

David

[Torper]

While HofG uncoupling using a "shunters pole" iof some variety may be considered blasphemy by some, it is nevertheless very quick, easy and effective with Dinghams.  All you do is flip the loop up - the latch on the other coupling ensures that it does not recouple when it falls back again.  It is therefore quite possible to uncouple and lift one vehicle out of a rake of goods wagons without disturbing any of the others.

 

DT

Edited June 15, 2017 by Torper

[34theletterbetweenB&D]

...What's surprising is the lack of used discussion on these couplings , it's as if very few people are using them in anger

 Liked the concept, of which others above have identified the salient features, but at the time I tried it about ten years ago felt it was under-developed in functional terms and way too laborious for the circa 800 wagons and freight traction it had to be fitted to.

 

Gangwayed coaches get Kadee, as this coaching stock was knuckle coupled. I want an equivalent functional quality to Kadee,  'near in concept to three link' coupler ready to go out of the box...

 

Still thinking about av design (while rather busy with more pressing family matters, story of my life these past five years.)

[BG John]

I've tried electromagnets, button magnets and an old crochet hook and all work equally well. For the electromagnets I salvaged the coils from some ancient point motors and, IIRC, there is a plan for one on the Dingham website. I power the electromagnet from an old power pack set for about (I've never actually measured it) 6VDC, too much power results in a violent bounce in the lifting loop that can sometimes jam it in place. Button magnets work a little too well but I have heard of some who raise and lower the magnet as needed which seems to help. The crochet hook is used to flip the lifting loop up and has the advantage that you can uncouple anywhere but does involve the dreaded H o G which some consider blasphemy.

 

Cheers,

 

David

Thanks. I'll have to do some experimenting when I get that far. The only power I need on the layout is 5V for the Arduinos and servos. I'm tempted to try servo lifted permanent magnets, or maybe even sliding them under the track. The track will be ballasted over the sleepers, so either may work, as long as it's completely hidden.

 

While HofG uncoupling using a "shunters pole" iof some variety may be considered blasphemy by some, it is nevertheless very quick, easy and effective with Dinghams.  All you do is flip the loop up - the latch on the other coupling ensures that it does not recouple when it falls back again.  It is therefore quite possible to uncouple and lift one vehicle out of a rake of goods wagons without disturbing any of the others.

 

DT

The HofG waving over the layout is out. The HofG will be holding a wireless control panel, and making everything work through an unseen force (AKA radio!).

[Torper]

The HofG waving over the layout is out. The HofG will be holding a wireless control panel, and making everything work through an unseen force (AKA radio!).

 

In that case, yes, electro magnets do work. They obviously have to be strategically positioned - see http://www.dingham.co.uk/em_inst.htm if you haven't already.  I've got six of them on my small layout and I could do with some more, almost certainly because I didn't think hard enough about where to put them them when I first fitted the six.  I do find, however, that when uncoupling vehicles in a stationery train the coupling dropper has to be positioned precisely over the nagnet, and the coupling has to be at the right tension, thus the perfectly prototypical buffering up mentioned in the instructions.  That can be a little difficult to achieve, hence the desirability of having some marker beside the track to indicate the precise position of the electro magnet.  You can also uncouple moving vehicles as they are propelled over the electromagnet and they will stay uncoupled provided that the train continues smoothly - any hesitations and they might well couple up again.

 

Whether you can control these electromagnets using radio I'm afraid I have no idea though I'm not sure why the HofG should be any more incommoded using a radio transmitter than it would be using a conventional hand-held controller.

 

DT

[BG John]

In that case, yes, electro magnets do work. They obviously have to be strategically positioned - see http://www.dingham.co.uk/em_inst.htm if you haven't already.  I've got six of them on my small layout and I could do with some more, almost certainly because I didn't think hard enough about where to put them them when I first fitted the six.  I do find, however, that when uncoupling vehicles in a stationery train the coupling dropper has to be positioned precisely over the nagnet, and the coupling has to be at the right tension, thus the perfectly prototypical buffering up mentioned in the instructions.  That can be a little difficult to achieve, hence the desirability of having some marker beside the track to indicate the precise position of the electro magnet.  You can also uncouple moving vehicles as they are propelled over the electromagnet and they will stay uncoupled provided that the train continues smoothly - any hesitations and they might well couple up again.

 

Whether you can control these electromagnets using radio I'm afraid I have no idea though I'm not sure why the HofG should be any more incommoded using a radio transmitter than it would be using a conventional hand-held controller.

 

DT

Smooth running should be guaranteed, as the locos will be battery powered, so dirty track and dodgy layout wiring won't be a problem. Electromagnets can be operated by relays, and servos for moving magnets controlled directly, by an Arduino with a radio link to the controller. The techie stuff is no problem, as it can all be built and tested off the layout, it's just the mechanical bits on the layout that get fiddly!

[Torper]

Here are some pictures of the jig I use to set up Dingham couplings:

 

This picture shows the complete jig wuth a van on it to give some idea of size.  It's big enough for everything from wagons to coaches and locos.

 

This shows the business end of the jig.  Picture 4 should make it clear how it works.

 

The rather tatty rear of the jig.

 

Hopefully this shows how it works.  The buffers buffer up to the the end stop, the hook rests on top of the central piece of plasticard shown in picture 2, just touching the bufferstop, and the loop rests on top of the bufferstop.  That should all perfectly align the coupling.

 

DT

Edited June 15, 2017 by Torper

[Penlan]

Progress report #1

The coupling hooks and loops, no problems at all.

The latches, I found it easier to do the type 1, simple fold through 180 deg's, add some solder.

The type 2 has been a pain,

Both latches however do not have enough weight in them to return downwards properly, and I wish I hadn't opened the latch holes up to 0.6mm, they allow the latches to move laterally to much and sometimes fall to the side of the hook, if they have dropped back in place.
I'm mindful there is very little weight variation etc., with both the loops and latches for gravity to have any real effect on.

 

The latches seem to have wasted a lot of my time today.

Right, walk the Dog down to the Legion to see what new ales are on the pumps, oh and rest my eyes.

[Penlan]

I had been intending to cobble an arrangement to mount the couplings onto bogies for coaches etc., but then I realised I have a similar loop on my coach sets, they are 6mm wide, are mounted through the couple hole in the buffer beam - so no need for sideways movement - and extend further from the end of a coach than the Dingham's will,  I will post some photo's later, plus my test track set-up.

 

I'm tempted to think I was led to believe coaches needed something more than being coupled as per normal, from other Dingham Topics, but perhaps they are using curves of less than 3' radius.

Edited June 15, 2017 by Penlan

[ozthedog]

I have converted one loco and a few wagons to Dinghams and I am very happy with the delayed uncoupling  which works very well if the couplers are all at a standard height.  Therein lies one of the problems as any slight variation causes problems.  Torper's jig should prove very useful when I convert the rest of my rolling stock.  I made my own electromagnets to Dingham's design and wound the wire onto the core with a borrowed jewellers lathe.  This just gives a nice slow rotation to allow control of the winding.

 

The electromagnet and the uncoupling can  be seen here https://www.youtube.com/watch?v=R4OsXLv-4Sw

 

I have also had the problem described by Penlan where the latches do not drop under gravity.  They would benefit from being heavier'

 

Keith

Edited June 15, 2017 by ozthedog

[Kylestrome]

For anyone who's having problems with Dinghams, fitted to bogied rolling stock on tight curves, here is my solution:

 

http://www.rmweb.co.uk/community/index.php?/topic/118922-kylestrome’s-4mm-workbench-–-coach-couplings-and-magnets/#entry2578180

 

Post #16

 

HTH,

David

 

PS. I use my Dinghams as auto-couplers and do the uncoupling manually with a wire hook.

Edited June 16, 2017 by Kylestrome

[Penlan]

Well time moves on - or to be correct, we pass time by?

 

Two pictures promised:

The first shows my test track and as will be obvious I use curves over 3' radius. 

'A' is a PK electromagnet, 'B' is a permanent rare earth magnet - very strong.

The white card between the rails is so I can see what's happening, if anything.

 

 

This shows the existing loop I have with fixed rakes of coaches, 6mm wide (inside).

 

Edited June 16, 2017 by Penlan

[BG John]

Well time moves on - or to be correct, we pass time by?

 

Two pictures promised:

The first shows my test track and as will be obvious I use curves over 3' radius. 

'A' is a PK electromagnet, 'B' is a permanent rare earth magnet - very strong.

The white card between the rails is so I can see what's happening, if anything.

 

Test Track.jpg

Does 'B' work with the Dinghams when you want it to, or does it uncouple everything that passes over it?

[Penlan]

Does 'B' work with the Dinghams when you want it to, or does it uncouple everything that passes over it?

Because the hook sits approx., 0.5 mm in front of the buffer faces*, the loop pushes against the other wagon coupling hook, and with the paddle form of latch, the loop is 'caught' under latch by it's pivot point.

* It would seem my buffer faces are between 5.3 and 5.5mm from the front of the buffer beam.

If I'm using Slaters buffers, I shall have to get some extended ones, 'cause these are short for a (correct) 6mm (1' 6") distance from the buffer beam to the buffer face.

 

If the simple fold-up latch is used - without the 'stops' - it all uncouples.

I think it is obvious, do not use permanent magnets, just Electro-magnets, or a HofG pole.

 

This is the wagons pushed together, thus they are not being moved buffer face to buffer face, which they should be.

The dropper wire is 0.45mm iron wire, one length hanging down, not the double twisted 0.35mm supplied.

 

 

On the coupling hooks there are a couple of very fine 'pegs' which you are supposed to bend over to be 'stops' to stop the latches travelling to far, sorry but they just mess up when I try to bend them, so at present they have been filed off.   All my work at the moment is exploratory, I'm happy to mess around with them.

 

In the end I anticipate of my 300+ wagons and 40 + coaches, approx., 30 will be fitted with automatic couplings.  The Dingham loops couple up OK to my standard '3 link' / 'screw coupling' hooks with no bother at all.

 

Of course I now have the problem of ensuring the coupling hook is set far enough back into the buffer beam, I've already taken off the pips - those who have these couplings will know what I mean - the buffer heads of course could be extended further, though these are glued up 'solid'.

 

The Wagons?  Oh some limited edition wagons from Swansea Model Railway Club, with replacement Cambrian Chassis for a 9' w/b.  Yes the lettering's grey'ish, their web page shows the '0' gauge wagon with nice bright white lettering.

 

I'm very much tempted to say I believe the instructions should say "... suitable for 3' and over curves...", not 'under'.

Edited June 16, 2017 by Penlan

[Penlan]

I did put some solder on top of the paddle latch to give it some extra weight,

but of course this will have to be painted black, the Carr's blacking for nickel silver won't touch the solder.

I didn't think it helped much.

 

I wonder about some of those - now illegal - fishing split lead weights?

[davknigh]

I had problems with the latch/paddle in the early days and sorting them comes down to two things. First they need to be very free in operation but not sloppy as that will result in more problems. Second the travel needs to be limited by the tab on the top or bottom depending on which style you choose. The latch really only needs to open a short distance to do its job and the closer to vertical it comes the greater the chance that things will go pear-shaped. The key seems to be the pivot, it must be perpendicular to the hook with a minimum of solder so as to give catch free operation. It may seem like a lot of faff but the smooth operation that results is worth the time spent.

 

Cheers,

 

David