Cincinnati Milacron Arrow 750 Retrofit

I quickly reviewed the 8i20 manual and it states that motor supply voltage can be between 35 and 400VDC. Does that mean the 8i20 can accept any voltage within that range and still produce up to 400V 2200W 3 phase power depending on available DC current?

I'm lucky enough to have the complete manuals for the servos on this machine. The motor I have is the 1FT6064-6AF71 on the Z axis. What you are describing is shown on the a, b, and c curves in the attached diagram below with regards to speed/torque and voltages.

If I'm understanding this information correctly, if the 8i20 is capable of supplying 400Vrms in 3 phase, then I should be able to produce a maximum speed-torque curve between curves b and c on the chart. I suppose if I'm using the maximum output of the 8i20 card, I will likely need to provide it with a full 400VDC voltage supply, if input and output voltages are closely related.

My plan is to retrofit the x, y and z axis servos with the 8i20 card. I think the x and y axis servos are the same as the z axis but I'm not entirely sure until I remove them from the machine.

Thanks for the feedback. I'll keep an eye out for the VFD power supplies you mentioned.

Does the power supply need to be able to provide +400VDC relative to ground or does it need to able to provide +/-400VDC relative to ground for an 8i20 card?

I've been working on this Cincinnati Arrow 750 retrofit for a little while now. I've managed to put together a working circuit to interpolate the absolute encoder on the Siemens Servo using the iC-NQC interpolator from iC-Haus. Right now I'm able to read the absolute angle of the servo in Hal Configurations with a resolution of 16384 points per revolution.

The next step is aligning the encoder zero point with the motor zero point. I plan on zeroing the encoder relative to the motor through a comp file I'm working on rather than physically aligning the two. I've connected a (+ve) power supply lead to the U lead and the (-ve) lead to the V and W lead of the servo motor and applied the rated stall current of 6.1A. Since it's a 6 pole motor, it rotates to 1 of 3 motor zero points.

The problem I'm having is that the motor doesn't consistently return to the same zero point. It seems the drag on the bearings affects the zero point repeatability by fractions of a degree. (The maximum current that can be applied to the motor is 33A at a maximum permissible speed of 9100rpm according to specs.) Should I just try to average the zero points at 6.1A stall current or should I further increase the amperage to further force the motor to zero? How critical is the motor zero accuracy? (I don't want to burn out the windings)