I am running real three phase well kinda (Phase Perfect solid state phase converter). Having real 3phase here is retarded unless you are a dedicated shop running all the time.
My spindle drive has the contactor on the motor side to change the winding configuration. I just need to tell the spindle drive to close the contact when M3 < 500 RPM and confirm that it is closed.
There is an input on the spindle drive which will energize the contactor coil, and there is a switch on the contactor to confirm that the contactor has closed. I have my control wired up and ready for it. I just need to decide which way to attack this, I rarely ever needed to run below 500RPM so it was always a back burner issue.
I had also thought about a M3 remap. I do not know if this machine did it on the fly in the past, I am going to go conservative on this and say that the spindle should not be energized during the winding change.
I will go check out "gearchoice"
Thanks Andy!