Leo
Thanks for your reply. The hole to which I refer is not on the face of the
adaptor (I am familiar with the four face holes for attaching the adaptor
and for use of the jack screws when removing the adaptor. The hole I was
referring to is a single hole in the part of the adaptor which sticks out
the back of the chuck. Your explanation cleared it up for me and I could
see using it if you had a flat on the shaft or could use some type of
polymer screw that would not damage the threads.
wrote in message
oups.com...
Hi Bob

The treaded hole is for keeping the chuck spinning off of the
headstock when you have a lathe that can turn reverse or one that can
be stopped quickly.
These lathes have a groove turned for the setscrew to tightened to,
metal lathes all have those grooves.
As your lathe does not have a flat groove, you probably don't need the
setscrew, but if you want to use one than the easiest way would be to
use a nylon/plastick setscrew, it will not damage the spindle thread,
or you could use a plastic plug between the setscrew and the spindle.

Have fun and take care
Leo Van Der Loo



On Mar 4, 2:44 pm, "Bob Daun" wrote:
I have used my chuck for quite awhile but I was just wondering why there
is
a threaded hole in the back end of the adaptor (the side facing the
headstock when mounted). The threads in the hole are quite fine but
there
is nothing in the hole. If I shine a flashlight into the hole I can see
the
threads from my headstock. Is this meant to use as and additional hold
down? I would hesitate to do that as it would ruin the headstock
threads.
Any thoughts on this?

--
Bob Daun