DoN. Nichols wrote:
On 2008-09-26, RB wrote:
I have, from an estate sale, a nice new 1/2" keyed drill chuck mounted
to an MT2 live center. The chuck rotates on the center.

What purpose would something like this serve?

For supporting the far end of something which does not have a
center hole -- and for whatever reason *should* not have one.

Back in the old days, Jacobs made chucks (without keys) for the
purpose of supporting the far end of a motor shaft while turning a worn
commutator. This one had bronze jaws, V-shaped to support the shaft
with out too much contact area, and with a ring to lock the outer shell
so you could adjust to be a slip fit on the shaft, and not have to worry
about the chuck either tightening or loosening during the operation.

I have one of these recently sold on eBay -- by someone who
thought that it was a standard drill chuck, and had no idea what the
locking ring was supposed to be for. Luckily, I recognized it for what
it was, and bid on and won it.

Your chuck may well lbe for this sort of purpose, except
designed to firmly grip the motor shaft, and to rotate with it.

Why not put a photo of your chuck in the dropbox
(http://www.metalworking.com) and post the resulting URL to here so we
can take a look at what you have.

Done. Posted as "chuck mounted to a live center" txt & JPG

I don't know how long it will take to show up.