I made the roto-plater myself.
Basically a 24rpm 12Vdc gearhead motor suspended over the tanks.
I put a resistor in series with it to lower the speed to about 16rpm.
I made a machined nose piece that fastens to the output shaft of the gearhead motor and a spring wiper spring makes contact (Negative DC from power supply) with the nose piece.
A 1/16" hole is in the end of the nose piece and the cathode hanging wire fastens in it with a allen head screw.
Always get perfect plating coverage (I also use (2) anodes and large air bubble agitation) and you don't have to stand over the solutions to turn/rotate the parts by hand.
The only expensive part is the Pittman gearhead motor.
Retail about $125.00 however, I have been getting them used, in good shape for $15.00 at a local surplus place.
Picked up the last one they had in stock on Friday.
They got a new shipment of a different brand (and have about 100 of them) new, for $12.50.
Not as well built (duh...$125 verses $12.50, but should last a year or so)
http://www.skycraftsurplus.com/index...p;Category=128
It is the 6-12Vdc gearhead motor on that web page.
It turns about 6rpm at 12Vdc.
I could send you some .pdf.s of my plans.
You would have to adapt the plans a little to fit the above motor however.
e-mail me if you want me to sent them.
About the largest parts I plate are about 50 sq inches because of my small tank size (2 gal tanks).
Because I plate mainly copper and nickel I usually do not exceed 5 to 6 amps.
George W.