RESULT (at last) :) Double whammy tonight :)

I had 20 minutes tonight and also had a chat with the VFD supplier this afternoon...

Double-checked my settings in the VFD and following advice from the tech guy I run an autotune sequence with everything connected up - apparently this is 100% vital with sensorless vector drives.

Huanyang vs Schneider Altivar... Like comparing apples and grapes!

The spindle sounds much smoother and quieter, draws less current too! No annoying resonance effects at certain speeds either. Success 1.

Happy with the way it was running I reached for the tacho in the hope that the speed ranges would be better, well they were, a tiny bit anyway but not enough for me!

I visited spindle pulleys again and raised the minimum speed to 6000, the result was that made my calibration worse, much worse - this gave me the light-bulb moment of realising that if lifting the minimum above zero makes the issue worse then surely taking the minimum BELOW zero would make it better - and oddly enough, it DID!

In the end I have a minimum spindle pulley of -6,500 and a maximum of +24,000 - I now have calibrated speeds from 8,000rpm to 24,000rpm to within about 200rpm of the requested speeds from Mach3 - success 2.

Next I thought i'd see if it had any power - called an S100 from mach, and gingerly tried to stall the spindle by hand - this was easy with the Huanyang drive, but I tried as much as i dare without risking injury and could not get it to stall or even change speed much! OK, so running at 100rpm is unrealistic - it uses more current, and likely won't do the spindle much good but knowing VFD's a little I know the power is usually naff at low rpm's.

So, at this stage at least I would say it's in far better shape now.

Tomorrow hopefully should be recalibrating the Z axis and starting test cuts again. I might even risk an old cutter and set the speed at the correct value, I have a feeling it will work this time and not bog down and break.