I'm a late bloomer. Taking forever to convert my two shoptasks into "super" machines. I have VFD's with 2hp 3ph motors. Just got them hooked up tonight and turned on. Wow! Incredibly quiet. Almost silent. Of course I've removed everything out of the case. So, I have one motor with pulley, one belt, going to spindle. No gears, no additonal "stuff". I push the button, bang 150 rpm, push again, bang, 1800 rpm. And any speed inbetween with the push of a button. Amazing. If any of you are considering a motor upgrade, this is a great option. Quiet and 2hp.