SFPM with aluminum.....

[Sid03]

I read on here that 5000RPM is the "sweet spot" for polishing aluminum.

Here's my problem......I have a 3450RPM motor. Its going to run the caswells bench mandrel with 2" pully. I prefer to use 8" wheels, as any smaller of a wheel and I risk the part hitting the shaft while polishing due to shape of the parts I got. That puts me up to 7225 SFPM. Anybody know offhand how to figure out how to change teh pully size on the motor to get the SFPM down? Is it even worth it?

Also.....I saw the bench mandrel is rated at 3000RPM MAX...........should i be worried about this?

[Sid03]

I think I figured it out..........anybody that can double check this, please do so.


If I run a 1.5" pulley on my 3450RPM motor and the stock 2" pulley on my bench mandrel, the mandrel shaft will be at 2587RPM.

With 2587 RPM and an 8" buff, I should get 5419 SFPM.

Does that all sound right?