Which, the radii cutter or the zero-center?
The zero-center is used like a coaxial indicator on a mill. You mount the stepped post in your quill using a collet or end mill holder. A dial indicator is attached to the left side (in the pic) of the block. You can then use it to center a circle or other misc. pieces to the quill. Here's a similar one from Enco's website:
The radii cutter is just that. The big crescent shaped thing is attached to the compound/cross slide of a lathe and is used to cut a radius/circle/globe. Here's a pic from Holdridge's web site:
Hope that helps,
-Ron
nice finds, post some in use pics or vids when you can
steve
I picked up one of the Holdridge radius cutters a few weeks ago (along with a $100 shaper). I did not realize until I got home that it was a $1000 tool, for which I gave $40.
I don't even know how to use the darn thing but it looks purrdy and now I want one! I think I have a problem...
Well, it was missing some pieces, and no wood case. It's also a smaller model than yours, but I haven't figured out which model. At any rate it's about right for my 9" and 10" lathes. It had all the main pieces. Very light rust.
I was a lot more excited about the shaper