Re: [CAD_CAM_EDM_DRO] Best source for inexpensive ballscrews?

On Fri, 1 Aug 2003, Bill Kichman wrote:

> McMaster-Carr's pricing is even cheaper than Reid Tool...you can buy "by the
> inch" and 5/8" diameter is seriously discounted compared to the other
> diameters....this is looking better all the time....so now if I buy the
> square nut only, how is that attached to the mill? I ask, because a
> standard flange likely won't fit my application anyhow, so I thought I would
> investigate other mountings...

I just got some of McMaster's cheap ballscrews and nuts for my micro-mill
CNC conversion. The nuts are a little crude, more so than I expected.
But then they're only $22 each...

Anyway I made my own simple preloaded nut. Take a block of aluminum or
whatever and bore a 15/16" hole through it, the same size as the outer
diameter of the threads on the ball nut. Now make a slit through one side
of the block all the way through to the hole in the same plane as the
centerline of the hole. Then drill and tap 2 holes perpendicular to that
slit so that now you have a sort of clamp. One nut goes in each side of
the hole so that the nuts are facing each other. When the screws are
tightened the nuts are then clamped in and won't move. When you assemble
this together with the ballscrew you can loosen one nut and turn it very
slightly to remove the backlash, then tighten it again.
Now you can drill other holes in the block to mount it to whatever you
want. Instant anti-backlash nut.

I can take some pictures of it tomorrow. That should get the idea across
much better.

C|