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?