PCB drilling question

In commercial CNC setups, is the drill motor powered during the entire
drilling operation (except tool changes) or is it cycled on/off at each
hole location?

 

I doubt any shop would do it that way

Me too. I foolishly went and bought a SSR with zero-crossing and
snubber circuitry for motor control in my CNC setup then realized that
even though X and Y speeds are slow at 20 IPM, it still probably didn't
justify cycling the power on/off at hole locations.