It's a cheap chinese drive, so I guess you pay for what you get.

for a 4 pole, you'd just set it for 12000 and be done.

I've assumed my 2.2Kw spindle is 2 pole and does spin at 24000rpm, it ties in with what the old VFD displayed (set up by previous owner). The guesstimated speed the other day ties in with the speed I used before for perspex.

I suppose the only real what to check it would be a strobe tacho on the spindle itself.

But, it's working, and earning, again.