How to Build an Electromagnetic Uncoupler for Your Train

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Duration: 4:11

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If you enjoy model railroad switching operations like Stony Creek & Western’s Gil Freitag, you’ll often find you need two hands to hold the cab throttle and speed knob, and a third hand to uncouple with a pick! Gil has come up with a solution to that problem, and he shows Model Railroad Academy’s Allen Keller how he scratchbuilds electromagnetic uncouplers buried under the track to accomplish the task. He even has the magnet on a timer which gives him about 8 seconds to make the uncoupling move, thus freeing up a hand – and it looks more realistic.

Gil also finds that making his own electromagnetic uncoupler gives him a more powerful magnet than the product made by Kadee. He purchased a product from Steel Company available at electrical supply stores, and cuts the core into pieces 2-¼” long. These will serve as his “uncoupling ramps.” He dips each in varnish for electrical protection and sets aside to dry for a day. Next, he wraps the individual pieces in 3M #27 Glass Cloth electrical tape to further insulate the core. Then, using #26 enamel electrical wire, he wraps the core lengthwise dozens of times; the more wire you wrap, the more powerful the magnetic force. His electromagnets draw about 3 amps each, so Gil recommends you have a good transformer.

When completely wrapped, he slips a slice of index card into the slot to protect the wire, and since it will sit just below the ballast level, he paints the entire surface of the core ballast-color.
Then, after determining where to place the uncoupler ramp, he cuts out the corresponding ties with a cutoff disc, and uses a utility knife and drill bit to hollow out a pocket in your subroadbed to accommodate the magnet, deep enough so the top of the magnet is at the level of your ties. He drills two holes in the bottom of the space to drop the lead wires from the magnet, places the electromagnet in the hollowed out section, and covers with a thin layer of ballast. The wire leads are attached to your transformer.

Uncoupling your model rail cars by scratchbuilding your own electromagnetic uncoupler has never been easier