Mike, If your focuser is the slightest bit 'sticky/tight' you may have to 'free' it up for the motor to drive it correctly/smoothly. Sorry, I don't have any old, 'blown/broken' servos left, (JUST FOUND ONE!)
. All you need is the drive unit (servo with it's innards ripped out, & a pulley wheel on the output shaft), an 'O' ring belt, a speed control with fwd&rev & a bracket to mount it on the focuser.
Regards, L.
