Thursday, May 7, 2015

Swing Arm Task Lamp

Swing Arm Lamp

Months back I made this articulated arm lamp but the arms were too narrow and didn't develop enough friction to hold the lamp without drooping over time.

I made this swing arm lamp as an improvement. It reuses parts of the original hinge with a longer central pivot.

The bottom arm has a dowel that engages one of three notches in the upper arm. The notches are only about 3/8" apart but allow approximately 20" vertical movement.

Lowest position
Middle position
High position
When swung left it lights up my drill press table. When swung right it sets above my lathe's headstock.

Here is a free plan. You will need to adapt it to whatever lamp you have. 

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.