DCC Controlled Uncoupler

I used Kadee #5 couplers. First straighten the pin, then bend it out at a right angle towards the same side as the knuckle return spring. Solder a length of small chain to the coupler pin about even with the return spring and cut off the rest. Pulling on the chain will now open the knuckle. I filed the lips from the coupler knuckles to allow easier uncoupling when just moving one knuckle. Another modification that improved operation was to file the knuckle stop back far enough that the knuckle may open sufficently to completely clear the pocket. Here is a couple of shots of the couplers in action and showing the modifications. (click here) 60 Kb

The actuators are built on a PC board base. The length just fits between the bottom steps, and the width is from the back of the running board of my Proto-2000 SW-9, to the back of the coupler pocket, (about 1/4") which just clears the brake rigging on the trucks. The actuator mounts under (bottom side when Loco is on rails) the coupler pocket using the normal coupler mounting screw. I put the screws into my Dremel tool and filed them into a countersunk flathead shape and counter sank the hole in the PC material, so they do not stick up above the surface of the PC board and catch on things. I actually used 1/16" thick fiberglass PC material, but removed half the thickness over the coupler poclets to provide more clearance. The following pictures are taken from the bottom side of the locomotive.  (click here) 163 Kb

These actuators require about 1/2 volt at 180-200ma. to operate. The DCC decoder functions supply 10 or more volts. This excess voltage needs to be dissipated safely. The electrical connections and current limiter are described. (click here) 136 Kb

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Last updated  05-14-98
Copyright © 1998 Dick Bronson