608 Ball Bearing Pulley

thingiverse

Apparently it's hard to find pulleys that turn well. I dunno what kind of load these will handle, but they look neat and the bearing press fits into the pulley nicely (press fitting best done while the plastic is still warm). Instructions The best way to press fit a bearing is to find a socket from a socket wrench set that exactly matches the outer diameter of the bearing, then use a press, vise, or hammer to put it in place. If your socket is too small it will crush the thin metal bearing protecting bit and the bearing won't turn.