Adding A Graduated Dial To A Compound Rest

[12bolts]

Dials on compounds are pretty much standard on every lathe manufactured in the last 100 years.
They dont do this out of fun. A lot of machining of small parts can be undertaken with the carriage locked and the cross and top (compound) slides used for x & y travel. With the top slide set at 90* to the cross slide your graduated dials make it easy to know how much you are taking off. Also, you can set your compound at 6 degrees from parallel, your actual movement is 1 tenth of the indicated graduation, (give or take a tinsy bit) so you can be really precise in your y feed.

Cheers Phil

 

[RJSakowski]

The problem with dials on a compound is they are off the minute you put the compound at an angle as in to cut threads.

That's where trigonometry comes to play. You will have the same issue with a dial indicator.

 

[Franko]

I use the dial on the compound of my PM 12-28 often. It is usually positioned in the X-Y axis and is much more controllable than the X-Y feed on the carriage.