More DCC controlled couplings

nigelcliffe
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More DCC controlled couplings

Postby nigelcliffe » Wed Dec 31, 2008 4:14 pm

Since the last posting in the autumn I've made some more progress with the DCC controlled couplings on locomotives.

Firstly, size of mechanism; I no longer regard this as a barrier even for retro-fits. I've made one where the mechanism fits in under 4mm x 4mm x 5mm, which is the space of an N gauge coupling pocket. This loco has proved to be very reliable.

Secondly, I've started experiments with AJ's which move in the normal "vertical" mode rather than rotating, and fitted one to a small High Level Coronation 0-4-0T.

Details of both are on http://nigelcliffe.blogspot.com/


Now to the semi-commercial bit.
Is anyone interested in adding DCC controlled AJ's to their locos if the parts were available ? It should be under £10 per coupling, hopefully a lot less.
I think I have found a commercial coil source in Canada (waiting for a small order to arrive to try out).
The brackets/pivots are a very simple item for etching in Nickel Silver.
Magnets are readily available from a variety of sources.


- Nigel

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Dave K
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Re: More DCC controlled couplings

Postby Dave K » Thu Jan 01, 2009 9:29 am

Nigel,

Does the loco have DCC chips, one for controlling the power and the other for the AJ or does one do both.

nigelcliffe
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Re: More DCC controlled couplings

Postby nigelcliffe » Thu Jan 01, 2009 10:42 am

dave k wrote:Nigel,

Does the loco have DCC chips, one for controlling the power and the other for the AJ or does one do both.


One chip in loco(*), using a function output for the coil on the AJ. One can wire both ends to a single function if wanted, or set them up on separate functions. In general one function output is enough, but there are a few cases where single output might be advantageous.

I use either Zimo or CT chips because of a few advanced features (and superior motor control to most other chips), but pretty much any chip could do the basics of turning the coil on/off.

If using "any old chip", I would suggest the following approaches, either:
a) a chip which can be programmed to only operate a function for a few seconds then go off - saves burning out a coil by leaving it on for an hour. (Note that TCS used to have a timed output, then dropped the feature a year or so ago, but some TCS manuals have not been updated)
b) map the function to a non-latching function key on the DCC handset (this varies by handset maker), such that you have to hold the key down to keep the coil active, and releasing the function key means the coil turns off.

This loco has a CT chip (Zimo can do similar but slightly different in fine details):
i) Coil is set to activate for about 3 seconds. This gives simple on/off of coil from a function key.
ii) Uncoupling movement is programmed to back-up loco about 1 sleeper, then operate coil, then (optionally) pull forward about 2 sleepers. This entire sequence is run by pressing a single function key.

The "clever" movement bit is about 10 different CV's in the CT chip. Its easy to setup with JMRI/DecoderPro (I've extended the CT definition file to include the uncoupler features and posted it back in the JMRI development ).



* the Coronation is small, and I could only get a DCX74/75 in it, insufficent space for a Zimo MX620 without carving away at castings (loco already built, so reluctant to break it!). Quite how I'd get two chips into an N gauge/2mm scale Farish 04 is beyond me at present !


- Nigel

allanferguson
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Re: More DCC controlled couplings

Postby allanferguson » Sun Jan 04, 2009 11:38 pm

If you were going ahead with commercial production, at the price you quoted, I'd be interested in a small quantity. This seems to me to be an excellent idea, and for me starting from scratch makes more sense than many underboard electromagnets. I'd still need some for goods yards etc, but the situation of a locomotive uncoupling from an arriving train and running round is ideally suited to your system.

Regards

Allan

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jim s-w
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Re: More DCC controlled couplings

Postby jim s-w » Fri Sep 25, 2009 10:24 am

HI Nigel

I hope you dont mind me posting this here but it seels a sensible place and kinda relates to the work you are doing.

A while ago I mentioned my preference for Dingham Couplings and my plan to operate them onboard via DCC. Well initial trials have proved more than sucessful and I thought I'd share the results with everyone.

Image

This is the coupling at rest. You can just make out a small magnet attached to the arm under the vehicle.

Image

By applying a small but opposing magnetic force above the floor the coupling raises up. The magnet on the coupling itself can be more easily seen. The magnet above the floor isnt really very big and will be replaced with a small electromagnet opperated via a DCC decoder. Other outputs from the decoder will be used to turn on/off a flashing tail lamp.

Its really simplicity itself (as most my ideas are!) with the added bonus that the vehicle can be uncoupled anywhere and (if being pushed) even on the move.

Cheers

Jim

nigelcliffe
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Re: More DCC controlled couplings

Postby nigelcliffe » Mon Sep 28, 2009 9:52 am

Jim, quite happy to see the thread expand to other system. It looks like a neat solution. The small Plantraco coils I am using might be suitable for your work; they are a fraction under 4mm x 4mm.


Etches and bit for the rotating AJ...
Those at Scaleforum probably saw my demo diorama with a variety of 0-4-0 industrials fitted with the coupler. (It also fits in a 2mm scale loco, so there is enough space in most 4mm models!).

I have a batch of etched parts to make up the pivoting box/counterweight, with a variety of counterweight arrangements at £2 each plus post. Discounts for bulk orders.
I plan to order one box of coils in the next couple of weeks. Please email me if you want to order a few coils. If needing more than half a dozen coils, its probably better to order direct than through me.

Closed position, counterweight to rear
img_1059.jpg
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open position, magnet visible at bottom
img_1057.jpg
img_1057.jpg (26.58 KiB) Viewed 11308 times


Installed under High Level Cornation class 0-4-0. Counterweight visible below. Due to low buffer beam, this loco has a cranked AJ wire and operates by swinging away. Larger locos with a "normal" buffer beam have a straight AJ wire and uncouple by just rotation of the head.
img_1014.jpg
img_1014.jpg (96.54 KiB) Viewed 11308 times

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John Bateson
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Re: More DCC controlled couplings

Postby John Bateson » Mon Sep 28, 2009 10:59 am

Detail of Nigel's work will appear in Scalefour News 165 due out 1 December.
But as my daughters were wont to say, 'brill!'
EditorJohn
Slaving away still on GCR stuff ...
Avoiding the soaps ...
http://www.greatcentralmodels.co.uk

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jim s-w
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Re: More DCC controlled couplings

Postby jim s-w » Fri Oct 23, 2009 1:47 pm

Hi All

Further to my idea earlier I now have my dingham prototype working entirely by remote.

I am indebted to Jeff Pugh for suggesting cheap relays as a source of electro magnets although I am also keen to try the ones Nigel uses to see if it will work on open or flat wagons, This one comes from a 5A DPDT 12v relay from Maplins (code n31aw) - Cost, less than 2 quid!

Image
Image

After a while faffing about with resistors and diodes I found you can just wire the decoder directly to the electro magnet. Its best to use a function that is latched so that you need to hold a button down to uncouple. (function 2 on Digitrax is set to this by default) to avoid leaving the coupling in its raised position. To couple to a smiths hook you do need to raise the coupling and then drive the loco up to the vehicle being coupled up.

HTH

Jim

nigelcliffe
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Re: More DCC controlled couplings

Postby nigelcliffe » Tue Nov 24, 2009 11:22 pm

I've put a few pictures of the most recent loco to have the rotating AJ's fitted onto a blog I keep

http://nigelcliffe.blogspot.com/

The main difference between this installation and previous ones was the generous spare space - what a difference a normal sized loco makes over the industrials I usually play with. I was able to mount the couplings onto removable PCB plates, then fit plug-sockets in the loco so the couplings can be added/removed without soldering.

I've also been experimenting with Vincent de Bode's method of bending AJ wires. His method puts the double section downwards (the lower part still bends towards the buffer beam, its a now double section rather than single). This moves the maximum stress point to the 120-ish degree bend, rather than at the 180 degree bend, and removes most of the levering force trying to open the bend. As a consequence, thinner wire can be used, which, in turn means a shorter AJ wire for the same amount of springiness.

Andrew Ullyott
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Re: More DCC controlled couplings

Postby Andrew Ullyott » Wed Nov 25, 2009 7:03 pm

Only just found this thread. Simple and ingenious.

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Rhobat Bryn
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Re: More DCC controlled couplings

Postby Rhobat Bryn » Sun Mar 10, 2013 11:01 pm

I have recently been researching having DCC controlled couplings for a P4 locomotive that I have recently commissioned. In doing so, I came across a discussion on the RM web by Jim W-S (I'm afraid I don't know his full name) regarding the use of Dingham couplings on the rolling stock, which is fitted with a DCC controlled electro-magnet, so that there is no alteration to prototype fittings on the loco itself. I have to say that I find myself persuaded by this system.

However I have a couple of questions. Are there any disadvantages in not having the closing latch which would normally have to be fitted to the loco?

Secondly it is also stated that this process requires a button which has to be permanently pressed in order for the loop to remain raised for the purposes of coupling and uncoupling, which can be found on the Digitrax system. Does anyone if such a facility exists on the Lenz system?
Nant Hendre - Rheilffordd Y Barri

nigelcliffe
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Re: More DCC controlled couplings

Postby nigelcliffe » Mon Mar 11, 2013 8:10 am

I can't answer for the Dingham latch.

The logic of using a "non latching" function key is to stop the uncoupler being left on for a long period of time. This might be a source of heat (bad) and it is also annoying when operating to find stock doesn't couple. Most decent DCC systems have either some keys set as "non latching" or an option to make them "non latching". I'd be surprised if Lenz 90/100 controllers can do this.

My personal preference is to use features in more advanced decoders to time the output's on time, this means the coupling is open for a pre-programmed number of seconds. But, even with this option there are trade-offs between decoder behaviour (subtly different between different makers such as CT, Zimo, ESU) and function key latching/non-latching.


- Nigel

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Simon_S
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Re: More DCC controlled couplings

Postby Simon_S » Mon Mar 11, 2013 8:42 am

Provided you've got the latest software updates, the Lenz 90 and 100 can have functions set to momentary action (non-latching). Very handy for sound functions :)
Cheers,
Simon

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Rhobat Bryn
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Re: More DCC controlled couplings

Postby Rhobat Bryn » Sat Mar 23, 2013 4:49 pm

Many thanks for the information regarding non-latching and relieved to discover that it is available on Lenz.

In his RM web entry regarding the use of DCC controlled Dingham couplings, Jim S-W refers to the use of a Smith's hook on his locomotive. Is this the name given to the prototype hook found on buffer beams for coupling or is it a tradename for the model hooks used for the same purpose?
Nant Hendre - Rheilffordd Y Barri

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grovenor-2685
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Re: More DCC controlled couplings

Postby grovenor-2685 » Sat Mar 23, 2013 6:02 pm

Is this the name given to the prototype hook found on buffer beams for coupling or is it a tradename for the model hooks used for the same purpose?

The latter, the hooks marketed under the Smith's name are somewhat over scale dimensions, and may therefore be a bit easier to use compared to the scale versions, eg. from Exactoscale.
Keith

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Rhobat Bryn
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Re: More DCC controlled couplings

Postby Rhobat Bryn » Sun Mar 24, 2013 10:18 am

Many thanks for the clarification.
Nant Hendre - Rheilffordd Y Barri

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Dave K
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Re: More DCC controlled couplings

Postby Dave K » Mon Mar 25, 2013 7:13 am

Simon_S wrote:Provided you've got the latest software updates, the Lenz 90 and 100 can have functions set to momentary action (non-latching). Very handy for sound functions :)
Cheers,
Simon


Simon,

Which software version do you mean, my Lenz 90/100 kit was updated to v3.6, is this the latest

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Ian Everett
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Re: More DCC controlled couplings

Postby Ian Everett » Wed Dec 31, 2014 4:57 pm

Nigel,

have there been any developments with finescale DCC uncoupling?

Ian

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Tim V
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Re: More DCC controlled couplings

Postby Tim V » Wed Dec 31, 2014 7:36 pm

Other than on my Workbench topic?
Tim V
Scalefour News Editor

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Ian Everett
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Re: More DCC controlled couplings

Postby Ian Everett » Thu Jan 01, 2015 10:48 am

Sorry, Tim. Somehow I missed that and can't even blame Christmas! :?

It's good to see you've finally cracked fly shunting: I know it's been an issue for you for a long time. It looks like an excellent system for a branch line station like Clutton where one cut is left from a pre-sorted stopping goods but I'm not sure it could be extended to a marshalling yard which makes up such trains from wagons from lots of incoming trains. I would like to do that with my planned Gormley sidings but I think it would be a step too far.

However,I was kept awake the other night thinking through the problem and I got to wondering whether it was possible to control three link couplings using DCC. All the mechanisms I have seen are for either AJs, Dinghams such as Tim's or various conspicuous commercial couplings (here the Americans have the advantage of buck-eyes which work well when scaled down). None of these solutions give the appearance of three-link couplings linking wagons.

My idea is as follows. It would use a three link or screw coupling made rigid, either by using twisted wire, castings or soldered-up.

Given a small enough mechanism, with either a servo or latching solenoid, it should be possible to make the three links either dangle vertically (uncoupled) or stick out horizontally (coupled). For the latter it would be necessary to have a thin wire either stocking down from the hook of the non-moving coupling hook or sticking up from the moving three links, engaging with a loop like that for S+Ws.

Somehow I cannot see anyone manufacturing something like that commercially and again it would be too complex and expensive for use on more than a couple of wagons. :( Nor does it deal with vacuum "bags" :( :(

It'll probably lead nowhere but I'm glad to have got that out of my system! Maybe I'll get to sleep tonight.

Ian

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Noel
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Re: More DCC controlled couplings

Postby Noel » Thu Jan 01, 2015 12:33 pm

If I have understood your thoughts correctly, Ian, it would leave the buffer faces out of contact, with all propelling forces taken by the rigid links, which I think would cause problems, as would coupling up with a rigid connection [which must, therefore, be of fixed length].

So far as Tim's system is concerned, with one set of powered vehicles it will be somewhat inflexible, even for a small yard like Clutton's. Clutton, of course, is purely an exhibition layout, with no home use, and Tim wants to replicate loose shunting in a context where the demonstration can be treated as a 'one off' rather than an ongoing exchange of vehicles over time.

Noel
Regards
Noel

nigelcliffe
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Re: More DCC controlled couplings

Postby nigelcliffe » Thu Jan 01, 2015 3:38 pm

Ian Everett wrote:However,I was kept awake the other night thinking through the problem and I got to wondering whether it was possible to control three link couplings using DCC. All the mechanisms I have seen are for either AJs, Dinghams such as Tim's or various conspicuous commercial couplings (here the Americans have the advantage of buck-eyes which work well when scaled down). None of these solutions give the appearance of three-link couplings linking wagons.


Uncoupling 3-links is easy, a "knocker off" lever lifts the link from the hook. Coupling up realistically is somewhat harder !

US buck-eyes are not easy; I've still not solved a challenge I was given six years ago to make a scale buck-eye (eg. Sargent) work remotely. Non-scale buck-eyes, such as Kadee/Microtrains are straight forwards.

My idea is as follows. It would use a three link or screw coupling made rigid, either by using twisted wire, castings or soldered-up.

Given a small enough mechanism, with either a servo or latching solenoid, it should be possible to make the three links either dangle vertically (uncoupled) or stick out horizontally (coupled). For the latter it would be necessary to have a thin wire either stocking down from the hook of the non-moving coupling hook or sticking up from the moving three links, engaging with a loop like that for S+Ws.


You may get some ideas if you study the MFK coupling for finescale 1:160
http://www.raw-nette.de/h_mfk1.htm

I have some MFK's in my parts drawer, so could bring them to a meeting place at some point in the future. They work because the coupling material is steel, so affected by magnetic field, unlike most UK etched parts which are brass or nickel silver.

Generating a large enough magnetic field within a vehicle is probably not possible with sane electromagnets, but it may be possible to design the link to do as you describe with an actuator (possibly a servo, a motor, or similar). The difficulty is not in lifting the coupling, but in controlling sideways slop in the hinge where the coupling pivots; its not impossible to my mind, just needs a fair bit of thought.


- Nigel


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