shimpo pottery wheel for spinning radius dishes?

[Bob Hammond]

Hello,

Someone gave me a Shimpo 21 variable speed pottery wheel. Our House Artist isn't particularly interested in pottery (busy with glass & painting), so I'm wondering if anybody else ahs repurposed it by placing a radius dish on the 12" platten. It draws 400 watts and spins at 0-250RPM, and seems to be sturdy. I think I could add a dish without damaging the platten so that it could be return to use as a pottery wheel. Any experience out there? Or should I just sell it?

[Bob Gramann]

If someone gave it to me, I certainly would try what you described. If it has a half horse (400 watts) motor belted and pulleyed down to a few rpm, it ought to have plenty of power for sanding. You could probably test the power by trying to grab and stop the wheel.

[Alan Carruth]

Make a pair of beams with the correct radius to go over the top of the wheel. Add a cap that goes across the bottom of something like 1/4" ply to make an 'L' section. Space them out so that your router can run between them. Adjust the depth so that the bit makes a shallow cut in the middle of the dish. Turn on the wheel and run the router slowly across the guide beam. Set for a deeper cut and repeat. Do this outdoors: while it's possible to rig a dust pickup that works pretty well it's hard to avoid getting fine dusty everywhere with this. This should make a smooth and accurate dish if you get the radius beam right.

The MDF I've used for these seems to have some built-in stress. When you remove material from the face they curl up. Gluing a piece of 1/8" or 1/4" Masonite on the under side prevents this. I just do that in my go-bar deck.

[Clay Schaeffer]

Hi Bob,
The pottery wheel should work fine. I've repurposed a couple of other machines for sanding dishes. The first was a bowling ball balancer and the second was a european mixer that runs on 220 so was less handy for my brother when he returned to the states. They both work very well and quickly! You have to check your progress often so you don't go too far.
Here are a couple of pictures of the mixing bowl version: