I installed a VFD in my garage a couple of decades ago an am VERY please
with it. I power my Bridgeport mill, Wilton geared-head drilling machine,
bench grinder, DoAll 26" bandsaw, and Clausing lathe with it. I use it at
full frequency output most of the time, but the ability to crank down the
speed for some operations like drilling large holes it very useful.

I think if you are patient and selective, you can pick up a used VFD for a
very reasonable price. Can't say that I remember what I paid for my VFD,
but I think it was in the neighborhood of $100 or $200. It was new surplus
and rated at 2HP, I think. Don't be too conservative in your power rating
selection. One of the great advantages of having 3-phase power available is
that you can bid on machines at auction that many guys have to pass up due
to power issues. I highly recommend the VFD. I have no experience with a
rotary converter.

awright

wrote in message
oups.com...
I recently bought a 3 phase 1 HP surface grinder. My original intention
was to replace the motor with a single phase unit. But the motor on the
grinder is closely integrated with the tool itself. I suspect that it
would be VERY expensive to take that approach.

So I'm looking at putting 3-phase power into the garage instead. Since
my shop is in my garage, I doubt that I could get the power company to
put in 3-phase power for any reasonable price. So I'm looking at
alternatives.

I ruled out static phase converters almost immediately.

But the choice between a rotary phase converter and a variable
frequency drive unit (VFD) isn't nearly so obvious. Each has good and
bad points - making the selection very difficult.

So, I'm asking you to help me choose. If you currently have or
previously had both types of units in your shop, which type would you
pick to power a 1 HP grinder?