Hey Peter, its Paul T., your lathes previous owner.

Sad to hear your motor is crapping out, I thought for sure that thing would
outlast me.

I vote for a 1HP 1725 RPM 220 volt 3 phase motor with a VFD, it will be the
cheapest one to buy, and often you can find used 3 phase motors in the 1 to
3 hp range for next to nothing since most home users are looking for single
phase motors.

When the VFD is set at 40 hz. you'll be at your stock speed, and although
the motor HP will be reduced, it will still be more than 1/2 HP. You'll get
useful power from the motor over the speed range of 30 to 120 hz., with
around half power at the endpoints. I take my motors all the way down to 12
to 15 hz. when tapping, and the reduced power actually helps you then,
acting as a "safety" clutch. A 2HP motor would be ok if you find a good deal
on one, 3HP would be overkill on that machine in my opinion, but if you find
one cheap, what the heck. Keep in mind the VFD's cost more for the higher HP
motors.

If you run the motor slow alot, put a 6" pancake fan on it to help cool it,
some guys get fancy and use a thermal snap switch to turn the fan on and
off. I don't run my machines slow very often or for very long, so I haven't
needed to add fans to either my lathe or mill motors.

I've got 3 Teco/Westinghouse VFD's I got from www.dealerselectric.com and
I'm pretty happy with them. Look there for your motor also, they often have
deals on VFD/motor bundles. The Teco manuals stink but they have a helpful
guy available on an 800 number. Wiring them up is easy, just single phase
220 in and 3 wires directly connected to your motor. You can also wire
control lines to start, stop and reverse the motor, keep that cool old motor
switch and wire it to the control input on the VFD, this is also easy to do.
If you get a Teco VFD, before starting it change the default output
frequency, for some dumb reason they send them from the factory set at 5hz.
Most motors won't even spin with a 5hz input, so a lot of Teco buyers think
the VFD is busted when they get it.

Another source for VFD's is www.automationdirect.com .

I would be careful running that lathe over the stock speed, remember its got
plain bearings on the spindle and you don't want to hurt those. It would
probably be a good idea to get some input from some SB specialists on how
fast you can run that machine without hurting the bearings.

Send me an email or give me a buzz if you need more input on deciding how to
replace the motor.

Paul T.