Step-up Converter for Mill

[Tangert]

The Step up Transformer that you are looking at is used to convert voltage from 120VAC to 240VAC its still is single phase or a polyphase not 3 phase. If possible you are better off going to your main panel and having an electrician run a new 240 VAC circuit similar to how your clothes dryer and your stove or run on. The reason for this is because when we Step Up voltage or amperage draw goes down while maintaining the same horsepower. Ohms law, Watts law. The more typical option recently for home machinist is to buy a variable frequency drive or vfd this will take single phase in and put out 3 phase in addition to that it very easily enables you to adjust the speed of your motor. You will need to look for one that has a single phase input in a 3-phase output that is also rated for the horsepower of your motor. Wolf automation has some affordable option (cheap) that work well on smaller projects. I prefer Allen bradlley products like the powerflex series. http://ab.rockwellautomation.com/Drives/Compact

Good luck. And be safe this is more deadly than 12VDC so make sure the work is being done by someone qualified.