I have had issues in the past with this spindle on a Chinese VFD, which is the one shown in the video.

Spindle Bogs down in cut. - YouTube

I switched out the VFD for a GS3 10hp and hadn't really had any issues since (but I don't push the spindle much at all, mostly V-Carving and 2.5D work), until I bought a new 2.25" spoil board cutter. I was running it at 12000 rpm, 300ipm, and the spindle stopped dead within about 4 seconds of cutting, with the cutter being ramped in on a 0.03 fly cut. By my assumptions, this setup should have had no issue with that cut at all.


Same as previous. If you look at the VFD (I never really paid attention to this before), the spindle was only pulling about 3.6 amps when it failed, and the VFD tried to push it to 6.6 but at that point it was too late.

So my question is this. Is it really the spindles issue, not the VFD. I would assume the spindle would be pulling 18 amps (max load) fairly quickly, or are the windings on 1 or 2 phases not working correctly?

I am not an electrical person, any help would be greatly appreciated.