On Sep 14, 3:37*pm, "Michael Koblic" wrote:

Mild steel disc - 5-8" diameter, 1/8" -1/4" thick.
The desired surface finish is:
a) Flat
b) Even
c) Equivalent to 300 - 600 grit
d) The reverse side finish is less stringent - 200 grit would do.

At this point there is *no* machine available for this. ...

So far all I have come up with is an old gramophone player - 33-1/2 to 78
rpm would be just right :-)
Michael Koblic,

There is, it's called a Blanchard grinder. A wood lathe with a large
faceplate might work, but don't sand or grind on a metal lathe unless
it's too worn for anything else.

The machines used to polish samples in metallurgical labs are
approximately what you need. They look like record turntables but are
much more solidly built since you press the sample against them to
polish it.

No go on the potters' or motorcycle wheel and a pad sander, like we
suggested?