Pete Macke wrote:
On Sat, 22 Jan 2005 15:46:44 -0500, Paul Kierstead wrote:


Pete Macke wrote:

If a shaft is turning at about 800rpm and you want to use a drive wheel to
friction spin a 12" disk at 30rpm what size should the drive wheel be?

Ok, assuming the drive wheel was at the very perimiter of the 12" wheel,
the size would be 12*(30/800) or about 0.45", ballpark 1/2" category
unless it is rocket science, in which case I recommend other means...


The problem then is finding a 'rack', maybe plastic that can be attached around
the edge of the disk.
Finding a small drive gear should be doable. I could probably fashion one out of
round bar myself.

By rack I assume you mean the toothed thingy that make up the connecting
part of a gear. If you application is not high torque, consider plain
friction drive. You can also certainly consider belt drive; often much
easier to do in a custom situation. The drive end in this case, being
only 1/2", will be troublesome; you would need to use a leather belt I
think. Perhaps a two-step process - an intermediate idler wheel such as
found on many drill presses.

PK