How Do You Determine Grinder Belt Speed

[CDHumiston]

I have KMG Grinder with a variable speed set up. The motor is a 1725 RPM Leesom. I am using a 5" Motor Pulley a 2.5" Grinder Pulley and a 4" drive wheel.

I bought an electronic rpm measurment device, but the tape won't stick directly to a belt so I have to stick it on the drive wheel.

So basically I can measure the spped of the 4" drive wheel no problem. What I need to know is how to convert that to belt speed?

 

[Fellhoelter]

If you know the rpm of your drive wheel, Surface speed in Feet Per Minute = RPM X 12.566 / 12

Pi x diameter gives you the circumference of your drive wheel (12.566")
Circumference X RPM give you surface speed
We divided by 12 because 12.566 is the circumference in inches.

You could also just multiply RPM by 1.047 (wheel circumference in feet)