John
Thanks for the advice as you raise some good points. We do have very nice Fanuc hardware here, but 3 phase is not an option for me. Sure I could get a rotary phase converter that draws 25Amps just sitting on the floor with nothing connected to it (we have one that we use to test 3 phase hardware before its converted to single phase, but we would not use it to run a machine full time, its very inefficient). 3 Phase, Single Phase, DC Bus, … you have think about power, each time you convert it, you lose some.
The Spindle Motor is AC 3 Phase for speed control only, the power input to the VFD or Fanuc Spindle drive doesn’t really matter it terms of performance as the VFD and Fanuc Spindle Driver convert the input power into a 500 to 800VDC Bus. Then they pulse width modulate this DC Bus to generate 3 Phase with a frequency range of 0.1Hz to 200.0Hz to control the RPMs of the Spindle while generating a voltage to match the motor voltage of 200VAC.
The rigid tapping feature is a good point. The old Fanuc Spindle drive had spindle orientation electronics on it used for the ATC Load/Unload spindle orientation and for rigid tapping. Mach3 supports rigid tapping as long as the hardware inputs are available, mainly a spindle rotation pulse (many others here on the forum use this feature). The old sensors are still on the Spindle and generate a quadrature output during rotation and the rotation pulse, so we should be able to use the ATC and rigid tap. However, I have not tested this feature yet.
JH