I built a pony start 5 hp for abut $30. Theirs plenty of info on the web for about any kind of converter you would want to build. The one I built will run my Bridgeport mill and a old 3 hp horizontal mill at the same time with ease. My biggest expense was wire and boxes old three phase motors can be had for scrap prices. Don't be tempted to use a static converter most gear head lathes without a clutch start realy hard.
