Kirk Gordon <KG1@gordon-eng.com> wrote

IMHO, the best way to mount a gearbelt pulley on a servo motor shaft,
or on the end of a ballscrew, is with a tapered bushing. The screw and
motor shaft should be straight, and without flats or keyways. This is
the only way I know of to ensure good concentricity, and to avoid the
problems that happen if the pulleys don't run true, or if they're out of
balance. Tapered bushings offer terrific grip, excellent concentricity,
forgiveness for reasonable diameter tolerances on the shafts, and the
substantial advantage that they never come loose or get sloppy.

T.B. Woods is my favorite source. They're in Stratford, Ontario,
Canada; and online someplace, though I don't have a phone number or url
at hand.

Kirk Gordon
http://www.gordon-eng.com