Re: [CAD_CAM_EDM_DRO] Ballscrew wipers?

We went through this issue (crud on ballscrews) with several axes over
the last several weeks. Here are my thoughts:

a) I doubt that wipers are the answer. The answer as far as I'm
concerned is *prevention* ie preventing stuff from getting on the screw
in the first place.

b) I looked at several commercial CNC machines and they all use a
substantial amount of shielding to ensure that no debris at all gets
anywhere near the ballscrews. On top of that, they typically use a
rigid plastic thread scraper to ensure that nothing gets to the
ballnut. My thread scraper I mean that it is like a plastic nut that
threads onto the ballscrew. Lastly, they force lubricant into the
ballnut which forces debris out.

c) How much shielding does a commercial CNC lathe use on the Z axis ?
The ballscrew is covered on 3 sides to several inches below the center
of the screw: the top and both sides are totally covered. The apron
attaches to the bottom of the ballnut. This uses much more material for
the same strength, but it keeps the ballscrew clean.

d) Due to the high feedrates and substantial amount of use they get, CNC
machines generate a ton of fast flying debris and a ton of cuttings in
general.

It gets everywhere. We'll be spending way more time and money shielding
things and trying to keep the debris contained than I ever thought we
would.

Example: what was once going to be an open table milling machine is now
going to have an enclosed table. Example: we were going to leave the
bed of our lathe open but will close it in shortly because there are
metal chips and coolant flying everywhere. When one is manually
machining something the feedrate isn't usually optimal. With a CNC
machine, you'll find yourself feeding to the limit of the spindle power
and the coolant flow will be increased to match. The result is messy
and needs to be contained.

Your mileage may vary.

On Wed, 2003-08-27 at 11:11, Torsten wrote:
> I am working on the antibacklash
> mechanism for two standard
> 5/8 ballscrew nuts the next step is
> to come up with some sort of wipers
> to prevent contaminates to get into
> the nut housing durring operation.
> I am thinking of designing something
> made of nylon to mount on each end of
> the unit.
> Any Ideas materials and ways to mount them?
> I try'd to find some examples on the web
> but was not able to find any good examples.
> Somebody must have done this before right.
>
>
>
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