I just checked the spindle speed with 2 different digital tachometers and found 3251 rpm when the dial said 2200. I can see a little off, but 50% under-reporting? Is this normal or is there a way to calibrate the dial? Probably can't calibrate the dial, because all I could do is add rpm, not multiply. Could this be due to a worn belt that is orbiting at a different radius on the cone pulleys, now?
cnc1000