Lathe Spider

[mklotz]

Nice job, indeed. I particularly like the wedge design. I'm going to add that one to my 'appropriated ideas' file.

And, of course, you realize that you've now made yourself a chuck depth stop. A simple rod will suffice but you can titivate it by drilling and threading the chuck end of the rod so that smaller diameter inserts can be used when the work diameter is less than the rod diameter. (If I were doing it I'd make the rod about 3/8" diameter.)