[Jared]

One trick is to make a collet that can be chucked in the three jaw. Make it out of whatever round stock or pipe you have. Turn a bore just a thou or so bigger than your sheaves with a shoulder inside a little shallower than the width of the rim. Then slit one side with whatever you have that will make a clean cut. The slit will allow the collet to squeeze the sheave when the chuck is tightened. I whipped up a quick pic with my CAD program but it isn't making it easy to post it.