Sherline stepper motors have shafts at both ends so that a handwheel can be used for manual control if desired. Flats are ground onto each end of the shaft to accommodate set screws for handwheel and coupling. If a stepper motor is to be used with a Sherline motor mount, the shaft going into the coupling should have a flat machined or ground on it where the set screw bites into it. If this is not done, the point of the set screw can upset the shaft surface sufficiently to make it impossible to remove the coupling.
Frame size: NEMA #23
Shaft: 1/4" diameter, dual shafts
Torque: 100+ oz. in.
Voltage: 3.2 V.
Current: 2 A
Step Angle: 1.8° (200 steps/rev)