I am looking for a little input in case I have missed something. I found
an old J-line bowl lathe and bought it. I am have been looking for a
motor to power it. I have looked at a bunch of motors, controllers, AC,
DC, 3-phase, single phase etc. I think I have settled on a DC motor
largely because of cost. After some searching and a lot of scrap paper
math I think I have made my choice. I have found a 1 HP totally enclosed
motor, 1725 RPM, sealed unit and rated for continuous duty. It costs
more than some of the other DC motors but it seems the better choice in
a dusty environment like a lathe. It

Having no experience with DC motors I have some concerns about the loss
of low speed torque. My plan is to run a variable speed control and
since my lathe came with a 3 step pulley on it and I I have decided to
use pulleys with a 3", 4" and 5" diameter and a second one with a 1
5/16", 2 9/16" and 3 3/8" dia. That way If I need to I can run the motor
at a higher speed and keep the spindle speed down and torque up.

On the lowest setting my max. spindle speed would be 455 RPM and I have
close to a 4 to 1 multiplication factor in my favor, so even at very
slow speeds I should still have plenty of torque. The next step provides
for 1120 RPM and a 2 to 3 ratio. The highest setting is almost 1 to 1
and would be way faster than I think I would ever need.

While I hope to just set it and not have to change the belt location at
least if I find that at slow speeds on larger items that I am lacking
torque I have the option to gear it down and speed up the motor. Or have
I missed something here?