I have a motor I am thinking about using for either a spindle sander or a home-made worksharp. The motor shaft is 1/2" with a flat spot for a set screw, no keyway. Motor is at 1075 RPM. It came off my condensor. A little slow for a sander but just about right for a slower speed grinder I think.
I am thinking I can use this spacer
inside a set screw coupling
to attach to the motor shaft. Then I have something to screw a spindle or wheel to. Would this work?