Pulley RPM calculator

[oldworldpiper]

For those that don't have a ridiculously high IQ like myself, here is a little calculator to determine the RPMs of a motor driven pulley system.

In my case I purchased a pulley driven variable speed bench grinder that uses pulleys to vary the speed. I knew the rpm's of the motor and the diameter of the pulleys but did not know the rpms at which the grinder was moving in its current belt configuration.

Use this calc to determine the rpms of your pulleys.

http://www.temecularodrun.com/ref/rpm_calc.asp

Sorry I know this probably pretty basic for most but this is all I can really contribute so far!

Go ahead and scrub it if this has already been covered in a thread.

[Massis]

isn't it just (drive pulley diam / free pulley diam) * motor RPM ?

So for example a 1" pulley on the motor, a 2" pulley on the other side, on a 2800 rpm motor, results in 1/2 * 2800 = 1400 rpm?

[oldworldpiper]

I do believe that is the right formula. I did not know it though until finding the calc.

Really though, my mission in the post was to brag about my sanding station that i got for 40 bucks! It would seem these belt driven grinders make for a nice versatile setup.

[Massis]

I do believe that is the right formula. I did not know it though until finding the calc.

Really though, my mission in the post was to brag about my sanding station that i got for 40 bucks! It would seem these belt driven grinders make for a nice versatile setup.

there's no need to hide such bragging, most of us like gear and shops So where's the picture of your sanding station?

[oldworldpiper]

Here the old girl is. I am thinking I may pick up an arbor from Kurt and add a buffing wheel directly to the motor.