Magnetic electrical connector for LGB Carriages and Trains

thingiverse

This is a small magnetic coupling that can clip onto the center buffer of LGB carriages and engines. It automatically links when the train couples to the carriage, making electrical contact from one carriage to another possible. I have used this to couple power from the engine to light the carriages without having to have track brushes on the carriage wheels. Instructions First drill out all your "part 1" parts to 3mm to accept 3mm magnets. (or 2mm for 2mm magnets) I used 3mm 1mm for the photographs, but plan to also try 2mm 2mm magnets later. Make one part up with a N pole up on one side and a south pole up on the other. Then superglue it to brass strip as this will be a very useful tool for making the rest of your connectors. Get 0.1inch ribbon cable and strip it to make a 2 core cable and strip the wire for aboout 8mm. Push this from the recessed side to the flat side, and then place two new magnets on the tool you have made. The tool holds these in the right place and makes sure that you have the N and S poles all the same for your trains. Push the plastic part onto the magnets, making sure not to short the bare wires, and ensuring that the bare wires contact the magnets. Fold the wires over the bottom, and superglue the recess on the back. (see photo) Assemble the wire first through the small hole in part 3, and then back trough the big hole and assemble part 3 onto the top of the post (part 2). The magnets should be facing outwards, with the wire fitting in the recess in the back of part 2. Adjust the height of the magnets to clear the buffer. Click the post onto the buffer and connect the wires to your lights etc. You can probably hide the wires better than I did in the photo! Testing an early version I discovered that they tend to lever apart from the bottom, which is why I'm now wrapping the extra wire over the bottom of the contacts in this revised design, so it should not need the magnets to actually touch to make contact. I have put the 123D files on here so you can modify for different magnets or make a different post to suit other carriages. I made early versions with two 2mm0.5mm magnets but they were very difficult to fit, as the magnets tended to tilt rather than pushing in nicely. A thicker magnet is probably going to work better. The 3mm 1mm magnets in the illustrations are better and push fit nicely once you drill the hole out to 3mm, but I am planning on getting some 2mm * 2mm magnets as well and I expect that they will be easier to fit.