"Dave Baker" wrote in message
...
Subject: Lathe chuck problem
From: Roger Hull
Date: 19/05/04 04:30 GMT Daylight Time
Message-id: t

The workpiece slides in (or out, depending on which way I'm cutting) on
my
Sherline 3.5 x 17 with the 3-jaw chuck. It just started this and I've had
it
four years or so. Plus my much older Clausing 12 x 24 never does this.
I've
cleaned the chuck and there is no oil on the jaw faces. I'm very puzzled.
Even taking just 0.005 cuts the piece just wont stay still. This project
involves cutting a ball, so a tailstock & center isn't the answer.

Sure would appreciate any insight. Thanks.

Are you sure the workpiece isn't so small that the jaws are meeting each
other
before gripping the part fully?


I'd sure be inclined to consider what Dave said. If not, your jaws might
benefit by some fine teeth, enough to provide a decent grip. Often 3 jaw
chucks have relatively smooth surfaces on the jaws in order to not mar the
items being held. Usually doesn't make much of a difference in that unless
the item matches the profile perfectly (like soft jaws might) the jaws still
tend to indent at the high spots, and often don't grip all that well because
of the smooth surface.

For sure, though, check what Dave said. Makes lots of sense.

Harold