I'd like to convert my Barber Colman gear hobber to a CNC machine. It would require the "Gear Box" or "Electronic Gearing" ability for the work spindle and the hob drive. My question is, what Fanuc CNC controllers have this option? After reading some of the other posts I"m thinking maybe they all have it and it's just a matter of turning on some parameters to access it.

Also, what's the difference between sync'ing two spindles and the standard (G01) command for sync'ing two servos? Maybe there's more resolution for spindles and opposed to servos? Higher speed capability?