Hi All,
I am nearing completion of the restoration on my recently aquired 10"
Sheldon lathe. As such, i am looking around at my tooling and
accessories to see what i can transfer over to use on the Sheldon. The
lathe came with what looks to be a decent 3 jaw chuck. I also put my
hans on (from a different source) a nice old SB 4 jaw. The backplate
on the 4 jaw appears to have the same thread as the Sheldon spindle,
except that the portion of the backplate that threads onto the spindle
is not as deep. As a result, the spindle threads will hit the back of
the chuck before the boss on the back of the backplate seats onto the
spindle face. There is a photo that shows the chuck on the spindle as
far as it will go, he

http://img.photobucket.com/albums/v4...e/PB060003.jpg

This shows the 2 different backplates, the 4 jaw is on the left:


http://photobucket.com/albums/v479/a...t=PB060008.jpg

Note the difference in the depth of both the threaded and the
unthreaded portion of the backplates.

My question is this: is there any reason that I could not just add a
"ring" of sufficent thickness to the 4 jaw plate (screwed or pinned in
place) that it would add enough depth to the boss to allow it to seat
properly? Or would I simply be better off getting or making a new
backplate? Any other ideas?

Thanks for any thoughts,
AL A.