I have a Bridgeport with a J1 head that has a non-original 2HP motor on it.
My motor runs at 1720 RPM, which I believe is different from the speed of the motors that originally came with the machine - which means that my actual spindle RPMs at any given pulley and gear combination are different from the numbers written on the machine and in the machine manual.
So, does anybody know of a spreadsheet or online calculator (or simply know the formulas) so that I can make a spindle RPM chart which is accurate for my motor?