Thanks for the replies.
From all the research I've done on the internet it seams like the Rotary Phase converter is more popular. One company in particular that I have found online (
http://www.gentecphaseconverters.com/) offers a rotary phase converter for a reasonable price. If possible I'd like to know what you think of their product.
Motor replacement is not an option. It would be very expensive.
I will be running motors up to 20HP and more than likely will only be running one machine at a time.
One of my tools in particular has two motors. One main motor 18HP and an accessory drive motor that’s 2HP. Does having two motors on one machine make a difference? Which of the converters will give max output power?