Hey Everyone, I have a project where I am building a 2x72" belt grinder. I have a perfectly good 130VDC, 4.25HP, 3170w motor to use. It came from a treadmill. My problem... how to power and then how to control. What I want is to power it as well as control the speed of it. I could buy an $800 electronic power converter with variable speed capabilities, but one... that is more than I am willing to spend, and two... what is the fun of just buying something when you can build something! :-D I have been out of major electronic projects such as this for a long while and I am looking for some ideas of how I can run this motor safely and for 45 min to an 1 hour at a time. All ideas are greatly appreciated!