retired machinist and CNC programer, operator

[Jacky]

I like in Georgia. Hobby is wood working now.
I like to keep up with what is new. Jacky

[Jon]

Hi Jacky - welcome to HomemadeTools.net

What are you thinking of building next? Can we help out with any ideas?

[Jacky]

LATHE DIVIDING HEAD
I thought the reader might be interested in a hobby shop project I did back in 1980. I bought a 12” x 36” metal lathe from Sears. It has a 10 thread cross carriage thread and the dial was radial. One round = .100” travel and .200” off the part. If you move the dial .010” then your part is .020” smaller. I wanted a diametrical dial. If I wanted my part to be .030” smaller then I turn the dial .030” smaller.
SOLUTION:
1- I turned a stainless steel ring with a slip fit over the factory dial.
2- I mounted a 50 tooth sprocket on the back side of the lathe spindle.
3- I rigged a jack-shaft with a 10 tooth sprocket connected with a chain to the 50 tooth. That gave me a 5:1 ratio.
4- I locked a 40 tooth sprocket on the jack-shaft. 40 x 5 = 200 divisions. (One tooth on the 40 tooth sprocket = 1/200 revolution of the chuck.
5- I mounted a v sharp tool sideways and cut the 200 divisions with every 5th line longer.
6- Then I stamped every 10th line with numbers.
7- I put a thumb screw to lock it in place and it worked perfect. I did a number of parts with a ± 1/10,000” tolerance. Sorry I don’t have any pictures. It was still on the lathe when I sold it a few years ago. Maybe someone can use this information. Jacky

[Jon]

Very interesting; too bad the tool was sold.

Keep us posted on your new builds