Kadee uncoupler

[Gary S]

Reinhard, it most likely isn't the coupler adjustment. Small changes in the speed of the loco as it moves along the track combined with variations in the "free-rolling-ness" of your rollingstock causes slack between couplers on occasion, and if the slack couplers happen to be above a magnet, then you get the unwanted uncoupling. Honestly, free rolling cars are the bane of magnetic coupling. You are better off having cars with a touch of drag in the wheels and trucks. I have never tried this, but have read that friction can be added by cutting a kadee coupler spring in half, removing an axle from the truck, place the half spring on the axle end and then put it into the truck. Another solution would be a piece of small diameter spring wire under one axle, then up over the truck, then back down under the other axle. Point is, the friction helps keep the slack out of the couplers as the train rolls along.

YOu can experiment with this... take a car that doesn't roll very well and put it on the very back of a train. Then run the train over the magnet as much as you want. It is almost guaranteed that you'll have no unwanted uncouplings because the non-free-rolling car on the back will keep all the slack out of all the couplers.

My solution was to use the permanent magnets only on spurs, and electromagnets on the "main" where trains routinely travel. I also weighted my cars at about 1.4 times the NMRA recommendation, which causes more friction in the trucks.