jim rozen writes:

Hmmm. I would stay away from a tapped hole to mount it to the
shaft, for the reason you say, this does not provide good
locational accuracy for the finished assembly. A better
design would be a straight bore in the phenolic, and a
round section on the shaft. The shaft could have a shoulder
at one side and threads on the other, a nut could compress
the phenolic up against the shoulder.

This doesn't work with the system we're using, for esthetic reasons. ;-( However...

Tapped holes do *not* work well if you are trying to minimize
radial runout. Just taking the part off the shaft, and putting
it back on, will give you a few thousanths of error right there.

How about a wheel that is tapped (half) and reamed (half)? Would the phenolic threads hold up? I would think so. Would the
half that's bored straight be enough to stabilize it? That's the way we used to do it, with a nylon insert in a wood wheel,
until we had several incidents of the nylon threads being stripped.

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."