Highclere - 2mm Finescale

Impressive stuff, very clever idea.

I see you opted for set length of wire rather than count the turns. Somewhere in my loft is an article by John Langan which dealt with how many turns were needed. Mind you I should remember it all. I worked as a development engineer for Xpelair and spent some time experimenting with shaded pole motors.

Basically the more turns the greater the magnetic field for the same current but the extra turns need finer wire so with thinner wire and extra turns the resistance id higher hence less current. The ideal of course is to find the optimum.

 

We also needed to make fusible links to prevent overheating. This was a piece of solder attached to one end of the coil in line with the feed. If the coil overheated the solder metlted breaking the connection. The girl on the production line that made them left and I had to go onto the line to show them how to do it. Probably overkill on a model but useful if coils are likely to be left switched on.

Neat work as usual Missy.

Thank you John and Don for the replies

 

Its nothing new or clever really. The idea has been around for ages but its something that I have needed to do for a while now. I thought it was worthwhile posting it as it might be useful to someone else.

 

I see you opted for set length of wire rather than count the turns. Somewhere in my loft is an article by John Langan which dealt with how many turns were needed. Mind you I should remember it all. I worked as a development engineer for Xpelair and spent some time experimenting with shaded pole motors.

Basically the more turns the greater the magnetic field for the same current but the extra turns need finer wire so with thinner wire and extra turns the resistance id higher hence less current. The ideal of course is to find the optimum.

 

Hi Don.

 

I took the easy route and directly copied the SEEP coil as this worked. I have used the same diameter wire and simply worked out how long it needed to be by working out the resistance per meter of the new wire and multiplied this by the total resistance of the original SEEP coil. I have tested my coils and I can confirm they do work! These ones seem to be quite resiliant too and you can keep the power turned on for quite a while. I just need to fit them to the layout now...

 

Missy

I do admire your approach. The idea of using a fixed length of wire seems much easier for home production.

Donw

I find that a fixed wire length is a lot easier than turn counting unless you rig up a mechanical counter. After a few of the same size, I usually stop even measuring length; just make them to the same size as the first ones. We're talking crude solenoids here, not precision instrumentation coils ! I measure the finished coil resistance to make sure its roughly what was expected, and that's the quality control finished.

 

I use shellac (crystals dissolved in meths) to fix the wire to my coils; paint a little on every now and then as I wind them. Mine can be tiny; 3mm x 3mm when finished for mounting inside locos (Missy has one I think).

 

I maintain tension by running the wire under the handles of my insulated pliers resting on a piece of MDF; far easier than holding the wire. I then guide its angle on the coil by gently pressing to left or right either with my finger nail or a small round probe.

 

 

- Nigel

Thank you Nigel and Don

 

I use shellac (crystals dissolved in meths) to fix the wire to my coils; paint a little on every now and then as I wind them. Mine can be tiny; 3mm x 3mm when finished for mounting inside locos (Missy has one I think).

- Nigel

 

Hello Nigel.

 

Yes, I have two (thank you), they are currently fitted to my 08 shunter (which I need to finish as well!)

 

Missy

Congratulations! Now you also know how to make guitar pick ups.........................

Seriously, have always enjoyed watching/reading of the progress of Highclere - superb work.

 

Best, Pete.