Re my previous post on modifying a drill chuck arbor from a MT 2 to a straight shank arbor... THANKS GUYS.. It worked... .,. I now have two new arbors with a 3/4" and a 5/8" straight shank-- custom made for my tooling requirements.
Here's how I did it.
The group's suggestions with the file showed that the arbors are hard, but not hardened. I used a carbide tipped tool and it cut the arbor just fine. I did not try HSS as most of my tooling is carbide anyway.
I first mounted the 2JT arbor in the drill chuck (pressed it lightly home). I first chucked the "solid" end of the drill chuck (near the 3 holes) in my 4 Jaw and supported the other end of the arbor with a live center in the tailsstock. I indicated everything off the drill chuck itself for a little less than .001" runnout. Work like a champ for the first arbor.
Then, I figured that what I really wanted was to ensure that I had minimum runnout on any given shaft chucked in the drill chuck, so I put a 1/2" ground dowel pin in the drill chuck, tighted that down with the drill chuck key using all three holes, put the 1/2" dowel pin in a collet in the headstock of my lathe, tightened that down and then brought up the live center to at the rear of the arbor.
This worked even better.. no fussing round with the 4 jaw and I had less than .001 runnout from the get go. (Jacobs really does make good chucks!!).
Took a while to machine the arbors down, and I did have to resharpen the carbide tool twice -- the arbor is hard-- but I was able to take .030 cuts with out too much problem.
Great fun last night.. feels good when something works.
Steve Koschmann