Friday, May 1, 2015

Rockwell Delta 46-111 Lathe, Part 3: Variable Speed

This will be my 2nd lathe converted to variable speed.
[edit; for some reason Blogger deleted the photos so I have edited this blog with updated info and pics.]

This is the lathe, a Rockwell 46-111, circa 1974. Which I have finished repainting. You can read more about the lathe in previous blog posts.



This is the motor: 1hp at 90 VDC. Big improvement over the 1/2hp original motor. It's from a popular brand of treadmill. Originally it had a digital control panel and extra boards but I eliminated all that and attached a 5k linear taper potentiometer from Radio Shack. The treadmill cost me $30. I listed the control panel on ebay and it sold within hours for $35, plus $25 for the scrap metal and I came out ahead.



Two things left to do.
[edit; I switched to a motor with a V pulley so everything from here down was unnecessary.]
  1. Make a new motor mount or modify the original. Shouldn't be difficult.
  2. The DC motor has a flat pulley but the lathe has V pulleys.


The most common solution is removing the flywheel and attaching a V pulley. I could do that but then I lose the torque benefit of the flywheel and extra torque is always welcome on a lathe. 

This chap had a great solution. Unfortunately I do not have a metal lathe and at 1-1/8" dia the flat pulley on mine is too small to accommodate a V belt. 


So I'm thinking I will make a 2nd pulley that will slide over the flat pulley. A 2" pulley would put me in the range of 3500 RPM at the spindle. I'll soon let you know how well it works.