If you're trying to emulate a normal golf swing, I'd go with something similar to an
Arm Style Pitching Machine. An over-center mechanism that slowly winds up, then rapidly swings forward. Or possibly just a simple catapult style system where you attach the club to a torsion spring, slowly pull it back, then quickly release it. Really, any sort of system where the club travels quickly for a short distance, then has to be slowly pulled back and wound up for the next shot. Otherwise, you're going to have a golf club swinging at ludicrous speed constantly in order to get any kind of distance out of the machine. Who on your team is going to be brave enough to tee up the golf ball in front of a golf club swinging at 60 RPM?