In continuation of this thread: max-rpm-miter-gears-designing-angle-head It is finally working.
It is controlled by an AB Micrologix 1200 plc. Mach3 outputs modal values via Modbus to the plc for rotation position of the head. The plc generates step & direction and drives the stepper with a Gecko G213V. After it arrives at position, an internal locking pin is thrown to guarantee accuracy and holding force.
See the video, this part took 3 setups previously!