In article , DoN. Nichols says...

How thick is the wheel at the hub? What pitch are the threads?
I think that you are using a wheel of about 1/2" thickness, which is not
really enough if half of its length is taken up by threads. And the
rather coarse threads which would seem to make sense in phenolic would
result in not enough of them to really trust.

I would think that from an engineering perspective, even a
half inch thick wheel could be mounted on a small shaft this
way, with a threaded shaft with a 'register diameter' on it,
the same way that a lathe chuck fits on a threaded spindle.

I would propose a design with 0.200 of very snug register
diameter, and 0.3 inch of threads, proabably about 20 threads
per inch or so, maybe 24. LE phenolic is actually really
really strong and threads up nicely. Key to this design
is cutting the threads in the blank fairly loose, so that
the register diameter does the work of centering the shaft.

Another approach would be to eliminate the threads altogether.
I would suggest performing linear knurling (not cross hatched)
on the shaft in the central region where the wheel fits, and
then boring the hub to be a very tight press-up on the knurled
section. It sounds to me like the driving torque is pretty
modest and I could imagine that a properly done press-up
onto knurling like that could have the .313 shaft twist
up before the joint slips.

Otherwise, this is similar to how a lathe's spindle centers its
chuck, with a register shoulder and threads for the force.

Oh. Great minds think alike! :^)

Do you ever encounter a player who likes to turn the wheel
backwards most of the time? Do you have problems with it coming off
under those circumstances?

The knurled, pressed-up joint would solve that issue nicely....

Jim

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