Re: Casting clearance WAS Re: sherline Ballscrews ....

> Date: Thu, 12 Oct 2000 09:38:57 -0400
> From: Ron Ginger <ginger@...>
>
> Anne Ogborn wrote:
> >
> > If you decide to do this, I've got the wax and routinely pour it.
> > I could try making a "thin sheet", but my experience is that
> > the wax is too viscous as a liquid to do this well.
> >
> > You're better off just shooting it with something a la mold release,
> > or even melting some wax and brushing it on.
> >
>
> The problem with any wax coating is that the thing I need to coat is an
> acme form screw thread, with the groove only 1/32" wide. Would dunking
> the screw in molten wax leave a uniform coating on the sides of the
> thread?
>
> And how would I control the thickness, remember we are trying to make a
> nut here with the lowest possible clearance- thats the whole point of
> the exercise.

<s>

I wonder if we haven't missed the real solution here. It was a part of
the original description of how Ron was able to remove the casting from
the screw. When he stress relieved by cutting the nut along the axis of
the screw he in effect made an adjustable nut -- ala kirk.

All we'd have to do is find a way to hold the now cut casting and squeeze
it with either a spring -- auto adjust -- or a clamp. This should
also allow usto adjust for the Vactra or whatever lube we plan to use.

With that done, a little bit of lapping with a portion of the screw that
we don't plan to use should take out the dimples in the nut's thread and
give us a good set of threads with reasonably controlled drag.

Ray