VFD setup help

Installed my ATC spindle finally after figuring out why it was overloading. It seems fine, except that it seems to not have the power it should. I assume I botched some settings with all the messing around I've been doing, but I'm not sure what.The spindle is 1.5kw, 0.24nm torque, 60,000rpm, 220vac. However my drive is restricted to 600hz or 36000rpm.As a result I have set the motor voltage to 132V which is 60% of 220v.At idle the spindle uses about 1.4 amps, which is roughly what is expected. Full rated amps is 5.132v at 5 amps is about 900w, which is a bit over 1 horsepower.However, at 5A, I am getting only 2 cubic inches a minute of cutting volume before the spindle begins to bog. Math says I should be getting 5 cubic inches per minute (machine rigidity notwithstanding). So I'm missing basically half my power it seems.What settings should I be looking for to rectify this? The drive is a durapulse G10, which is a stripped down verison of the delta MS300. It is running in vector control mode. The drive will not autotune for some reason, it overloads. I suspect there are some motor parameters I need to manually enter in for it to behave but I'm not sure. My other spindle (also a delta ms300 drive) just autotunes and works as expected no fuss.

Are you sure you're supposed to be reducing the motor voltage?

I don't think you need to drop the voltage due to your VFD not having the frequency to match the MAX frequency of the spindle.

Pretty sure if it's a 220V motor on the nameplate then that's what it should be set to in the VFD. The vfd will be making a bunch of calculations based on that value and so it should be the true value. It just will top out at 600Hz.

Putting the correct motor voltage in will probs allow it to do an auto-tune without failure too. Use all the data from the nameplate on the motor

The only time I have had to stray from nameplate ratings was when I had to up the current 0.5A over the nameplate rating a couple of times to get through some spindle run-in before putting it back to the correct value.

Every motor that is controlled by a Variable frequency drive...... Changes speed by frequency not voltage.... Hence the name!

It's not pwm like you see in small DC motors, universal motors, AC router speed controllers, etc

The drive coverts ac from the wall, into DC, then back into AC at a varying frequency to control the motor speed. Trying to keep voltage at name plate specs.

It makes sense that at ~half the voltage you have ~half the torque

Fix that quickly or you will fry that spindle.


Second thing to watch out for is endmill size. Too big and it won't have the torque to spin it even if it has power on tap (try loosening a rusty bolt with a stubby wrench... Same problem). Drop down an endmill size or two. I'd try in the 3-6mm range (1/8 to 1/4 in) for a spindle like that.

I was told to set the voltage by the manufacturer. This is mandatory or you fry the spindle. Spindle speed corresponds to voltage, hence the v/f curve. 220 is full speed, 110 is half. etc. I am at 60% so 132v.

The drive eventually autotuned itself, and it's much better now, but not perfect. Still bogs down and uses more current than it should. Still seems to be about half or a little more power than it should have. (at 36000rpm it should be 900w, and its bogging down on 400-500w cuts at 5A).

thanks