I have a Chinese water cooled 2.2kw spindle. I am using mach3 to control it. It's in an cncrouterparts 48x24 cnc I put together.

I've tried all the parameter settings and can get it to work, sort of. Mach3 can turn on and off the spindle. The spindle speed in mach 3 shows a similar (within a few hundred) rpm at low speeds with the vfd. however, at higher speeds it's off by as much as 5k.

Example
mach 3 says 10387 vfd says 10660
mach 3 says 11985 vfd sats 14380
mach 3 says 13583 vfd says 18050
mach 3 says 15181 vfd says 21782

I am using the spindle cwf5 button to start and stop for this example. I am using the +/- key to control spindle speed

I've read a lot of forum articles and not sure where to go with this. Is it my pd settings on the vfd or a pully / calibration issue in mach3