Well, I’ve had some success with my home-brewed turntable drive. It still needs some fine-tuning. Here’s the story so far. Drive parts: 12V 3 RPM gearmotor; ¼” to 1/8” shaft adapter; universal joint made for model boats; and two 1/8” shafts. All ordered from ServoCity.com. Here’s an upside-down view of the gearmotor mounted on a homemade styrene channel and two wooden blocks. I did as much work as possible at the bench before installing the base board on the layout. I bought the cheapest wired decoder my local hobby shop had in stock. I didn’t care about the brand since all I need is basic motor control. I clipped off the blue, white, and yellow wires and soldered the remaining four wires to a Radio Shack terminal strip. The terminal strip is riveted to the motor mount channel. Double-sided tape keeps the decoder in place. I temporarily hooked up the wires to the programming output of my DCC command station. I set the address to 999 since I’m not likely to use that number for anything else. After setting the address, I connected the wires to the track output (before any breakers). The biggest drawback to this control method is that it takes up an address on the controller, leaving one less for locomotives. It works! I haven’t fiddled with CVs at all yet. Rotation speed is good, but mechanically it is not as smooth as I would like. I think there’s too much friction where the turntable bridge rests on the pit rail. I’m thinking of getting some UHMW tape (slippery plastic) as sold by woodworking stores, and putting small pieces on the bottom of the bridge. Maybe a little plastic compatible grease on the center pivot, too. Other ideas appreciated!
