If you want to use inexpensive scratchbuid magnetic uncouplers for Micro trains or Kadee couplers...

Model Railroader General Discussion (Model Railroader)
1

Hi,

Sorry but I do a few mistakes before I could use the sending photos process on the forum.

By personnal request of forum users let you explain how I scratchbuild my magnetic uncouplers.

I was inspired by a sketch published in MR a few years ago. After a try and some modifications I come with a very reliable and powerful uncoupler and completly invisible.

The following mesurations are for Nscale, but for HO I have build for a friend a uncoupler with a 3/8 diameter tube. The opening of the cap was close to a around 8 millimeters. Other mesurations are ok for HO scale.

You need just a metalic tube of a average 12mm diameter and 40mm length, two pieces of plastic of 20mm X 40mm and of course isolated cooper wire of 0,5mm diameter.

Cut lengthwise the tube to obtain a “U” shape tube.

When you have the cut done put the tube in a drill press vise and shut the opening of the “U” to 5mm. When done, smooth all the cutting edges with a file. Its very important that the tube is smooth as possible.

Take the two plastic parts and glue them alongside the tube. To do that put the tube, cap side, on your workbench and glue with a five minutes epoxy the “plastic wings” square alongside the tube.

When done put an heavy coat of paint on the uncoupler.

Now it’s just a matter of rounding the wire around the tube. Just be very careful and take care when doing it because you could hurt the isolation of the wire.Don’t round to much wire over the cutting side of the tube because we need a flat area to put it under the track

Take an ohmeter and check the uncoupler to see if there is no short. Make a try oit with a piece

2

I tryied this several years back, and could not get it to work very well, Your design seems more refined and cost effective. Thanks for the pics and info, now I know what I did wrong.

3

Marc,

Thanks for sharing your idea with us. That’s a neat idea, and I’d love to try it out the next time I build a new layout section. Sounds more idiot-proof than fixed permanent magnets, and much less expensive than buying pre-made electromagnets. It’s stuff like this that really makes the forum a valuable resource of information.

However, I got a little lost in the procedure between the second photo showing the parts and the next photo showing the finished assembly. I was a little unclear on what exactly you are supposed to do in the vise, and how the parts go together. Any chance you could post some intermediate assembly photos, or draw up couple of sketches or something?