Tony Smith wrote: > Given the prices on this page > , > that's probably not an option. Yes, that's what I'm seeing a lot too :) As Alan said, finding a suitable manufacturer is probably the biggest problem. The ones I've seen so far are either way too expensive already with their stock parts or are working in quantities where they are really not interested in making a custom part for us. > Looks like your stuck with trading speed for torque, get a motor and gear it > down. Servos on CNC machines are usually geared down (say 1:5), so pulleys > & belts are common. I'm leaning towards using my current motor (which is relatively inexpensive for the torque and power it provides) together with a belt or chain. > 50Nm is a lot of torque, what are you making? Basically a servo drive for moving push-pull cables, with forces up to 800+ N and a throw of 7 cm. So far we're moving the cables with levers mounted to the motor, but the belt/chain drive would give more freedom in the translation of the rotation into a linear movement. That way, I could increase the force without losing throw (as I do with the lever). Gerhard -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist