I am in the process of assembling my headstock and have a couple of questions.
How close to the motor case does the sheave go?
Where does this bushing go?
The bushing looks like the one that goes on the motor shaft behind the fan sheave. It serves as a spacer to set the spacing between the fan sheave and the motor housing. If memory serves me correctly the spacing should be about 1/8". Or whatever the bushing will give you. The set screw in the fan sheave should hold the keyway in place.
Bill V