For the last week, I've been sifting through threads here and elsewhere about running a 3-phase lathe on single-phase power mains. It's making my brain hurt and although I've learned a lot, my concerns are still lingering. I'm purchasing the Grizzly G0740 3-phase (2-speed) lathe. Adapting a VFD to a 2-speed lathe (especially a brand new lathe) is just too labor and skills intensive. All I really want is 3-phase power suitable for running the 5hp (max) lathe. I don't care anything about frequency control; the lathe is fully adequate in stock condition for my needs. Almost all of the controls would have to be wired directly to the VFD for jog, reversal, speeds, emergency stop, brake, etc. I don't want to butcher the lathe with a whole new control panel. So it appears that a rotary converter is the ticket. The lathe has a 5hp 2-speed motor. I doubt I'll ever use the highest speed at max current draw; so is a 15HP rotary converter really required? The price jump to build or buy a 15HP rotary converter is much higher than a 10HP. Would a 10HP suffice? And finally, doesn't anyone make an electronic phase conversion unit that is straight 60hz to 60hz and simply converts from single to 3 phase? All I want is 3-phase power for the lathe at max 20 amps. I want to keep the lathe totally stock. OH, or maybe simply replacing the motor would be the thing to do. A 5hp 1750 rpm single phase motor would do it, but I'd probably need to change the drive pulley so that the spindle speed range would fall into useable rpm like other single-speed motor lathes.