I just discovered this thread yesterday. Just for general information for anyone wanting to do a similar turntable, Micro Mark www.micromark.com offers a motorized planetary gearbox system for $34.95 part number 82722. The motor will operate on 6vdc to 24vdc at speeds from 8500rpm to 19680rpm, and it is polarity reversable. It comes with color coded, stackable planetary gear sets that reduce the output speeds to 13.8 rpm up to 6560 rpm. I've never bought or even seen one, but it looked like a good candidate for powering a turntable at a slow speed.