On Saturday, July 28, 2018 at 9:30:20 AM UTC-5, Jack wrote:
On 7/24/2018 12:13 PM, Dr. Deb wrote:

Bill, I have not looked at your motors, but one thing you absolutely need is a TEFC motor, otherwise
the dust will ruin the motor.

Absolutely is a strong word. Most of my stationary tools are circa
1954, including my Rockwell lathe, do not have TEFC motors and have been
running for that many years. The motors now are inclosed in there
respective cabinets except for the contractors saw.

The contractors saw is the only one that ever had a problem. It got
packed with saw dust and needed pulled apart and cleaned or the starter
switch gets stuck. 30 years ago I put a nylon stocking over the cooling
vents to keep out large chunks and it's been running fine with nary a
glitch.

I might add that I'm pretty sure Rockwell sold these tools with the
motors, which always seemed odd to me. Didn't they have TEFC motors back
then?

Not saying you shouldn't use TEFC motors, but I "absolutely" know my
motors have been running for over 60 years w/o them, and no fires, no
nothing other than the TS issue 30 years ago.

To the OP, I've been running stepped pulley's on my lathe since forever,
as have millions of turners. Variable speed motor would be nice, but
not even close to necessary. Make sure your belt is loose enough to
make moving it around easy. As a bonus, the belt slips under a jam.

--
Jack
Tolerance is the virtue of the man without convictions.
http://jbstein.com

But, whether or not a TFEC motor is required depends on where its located. Put an unenclosed motor right in the path of dust coming off a lathe and you will have problems. The motors you are talking about are enclosed, with the exception of the table saw, which did have problems.

Can you run an unenclosed motor? Sure. But an enclosed motor is just less prone to problems.