--- In 7x12minilathe@..., "John" <moran03@e...> wrote:
As part of adding a ball bearing and more travel to my cross slide I
removed the cross slide lead screw. I noted a sludge on the lead
screw which looks like powdered brass mixed with grease.
I suspect that the lead screw threads were simply cut and not
polished. The surface finish on the lead screw seems to be chewing
away on the soft brass and this process will probably continue since
the brass won't polish the roughness off the steel.
I suspect you are right.
Is polishing the lead screw a good thing to attempt? Is there a
better way of polishing the lead screw?
I think so, although I have never tried it.
I have *lapped* a lead screw thread on another machine, and it does
seem to have worked well.
I cut a matching thread in a piece of aluminum (it needs to be
something soft). I cut that in half across the thread, and put two
screws in to clamp it back together on the thread to be lapped. I
used a little lapping compound while running the lapping tool back
and forth by running the lathe in forward and reverse. Every few
trips (laps?) I tightened the screws slightly, keeping it just tight
enough to feel a slight drag. I think it would be easier to get it
too tight than too loose - too loose would just require a little more
lapping.
I hope that is clear enough. If you have questions on the process,
just ask.
RA
