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'Dingham' couplings - solenoids for uncoupling?


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Hi all -

 

I've just bought a trial pack of 4mm 'Dingham' couplings. I also bought one of the 'Dingham' electromagnets but the 'blurb' suggests the maker is not keen on spending modelling time winding lots of armatures! A possible solution in the form of redundant Peco PMs presents itself - splitting them in half and using them as the electromagnet. Before I cut one up - has anyone else tried this, and if so, did it work? Any other comment gratefully appreciated.

 

Regs

 

Ian

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Ian,

 

Yes and yes if you want the short answer. Long answer is that I took a couple of ancient point motors and did as you proposed but turned some new iron cores as the existing ones were not long enough to fit both the coil and get through the baseboard to the track. I run them with push button on an old train set power pack at about 7 volts (TBH I never measured the voltage, just going by the throttle position) and the work just fine. Probably trashed a valuable antique :O

post-5047-0-69607800-1339208337.jpg

 

I haven't got any pics of the finished product at the moment but will do one in anyone is interested.

 

Cheers,

 

David

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Guest Moria

Yes it can work but you have to permanently attatch a core inside the coil.. the point motor relies on snapping the floating core from one end to the other, in an uncoupler you need the core to stay stationary otherwise you will be shooting someone with it or propelling it through the baseboard :)

 

Two ways to do this.. one is take the coil and permanently attatch it to a soft iron nail or similar, the second would be to use the peco uncoupling magnet which has a core already attatched and is one coil from a point motor and looks like this :-

 

Peco uncoupling magnet

 

Regards

 

Graham

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Hi Ian

 

One thing to bear in mind is that most ex-solenoid coils will draw a much higher current than the Dingham electromagnet - Trevor Shaw does explain this on his website - so make sure that your power supply and switches are adequate.

 

An easy way to mount ex-solenoid coils is to use the same method as those supplied by Trevor - use a suitable diameter steel machine bolt and screw into the baseboard.

 

Regards.

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A pic of the modified point motor mentioned before.

post-5047-0-30609400-1339252948.jpg

The main bracket is Evergreen plastic as is the angle, I used the original metal bracket to hold the coil at bottom and supplemented it with duct tape.

 

HTH

 

David

 

PS, what sort of magnetic couplings does Peco make?

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Very interesting. I've got some ancient H&M point motors - am I right in assuming that the coils from these would probably be suitable? And if so, how do measure just how much current they will draw?

 

DT

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Any point motor should, in theory, work. I did strictly trial and error, no instruments involved. After first testing the PM to see that the circuit was still complete I held the button down for 30 sec. or so, if no heating (there was none) then no excess current draw. I also checked to see that the magnetic pull was strong enough to work the coupler before carrying on with the rest of the work. Apparently ex-GPO solenoids also get used but they are a bit thin on the ground on this side of the pond :no: .

 

Cheers,

 

David

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PS, what sort of magnetic couplings does Peco make?

AFAIR, they did a magnetic version of their 'Simplex' coupling,

it had a girls name [!], but I can't remember what it was, and I'm

not going down the shed at this time of night to check!

Jeff

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dear all -

 

Many thanks for your informative responses - once again RMWeb reaches places others dont't!

 

I'll go with the Peco pm option at the moment - I've got them available - but I'll bear in mind their uncoupling mech as well.

 

Once again, my thanks

 

Ian

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I would have liked to try these couplings in 2mm scale but, sadly, Trevor didn't seem to think much of the idea.

 

David

 

Hi David

 

If B&B couplings are still available, these are very similar. They require mounting under the buffer beam rather than using the coupling hook slot - this may well be easier in the smaller scale.

 

Regards.

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Hi David

 

If B&B couplings are still available, these are very similar. They require mounting under the buffer beam rather than using the coupling hook slot - this may well be easier in the smaller scale.

 

Regards.

 

Bill,

 

B & Bs are a clunkier version of the DGs that I already use. I liked the idea of using the hook on the Dinghams and dispensing with the buffing plate. I suspect that Trevor thought that they may not function as well in the smaller scale.

 

David

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Bill,

 

B & Bs are a clunkier version of the DGs that I already use. I liked the idea of using the hook on the Dinghams and dispensing with the buffing plate. I suspect that Trevor thought that they may not function as well in the smaller scale.

 

David

 

I should think the issue in 2mm is one of mass?

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A pic of the modified point motor mentioned before.

post-5047-0-30609400-1339252948.jpg

The main bracket is Evergreen plastic as is the angle, I used the original metal bracket to hold the coil at bottom and supplemented it with duct tape.

 

HTH

 

David

 

PS, what sort of magnetic couplings does Peco make?

 

Thanks for the image David - and looking at the top of the iron rod it looks like a pretty efficient trap for metal filings etc?

 

Regs

 

Ian

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Thanks for the image David - and looking at the top of the iron rod it looks like a pretty efficient trap for metal filings etc?

 

Regs

 

Ian

 

Actually that's ballast, but there may be other bits in there too :yes:.

 

Cheers,

 

David

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I should think the issue in 2mm is one of mass?

 

I can't think that mass would be an issue, Ian, as they work on similar principles to DGs/B&Bs. I just think that they are better looking in that they use the fixed hook and no buffing plate which allows the buffers to perform their proper function. Anyway it's a bit academic as they aren't going to happen.

 

David

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AFAIR, they did a magnetic version of their 'Simplex' coupling,

it had a girls name [!], but I can't remember what it was, and I'm

not going down the shed at this time of night to check!

Jeff

 

"Anita" coupling?

 

I always use MSE's electro-magnets.

 

Ian

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Guest Moria

"Anita" coupling?

 

I always use MSE's electro-magnets.

 

Ian

 

 

 

Wasn't it Elsie?

 

Regards

 

Graham

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