RE: [CAD_CAM_EDM_DRO] Does this make sense? was Re:Bent Nookballscrews ?????

Yes, I read them and I fully understand them.

Did you ever replace the wheel bearings in a car ? The two bearings act
the very same way as the ball nuts do on a ball screw. When you tighten
the preload the drag increases. The amount the drag increase is
proportional to the preload and in our case, with a 5 TPI ball screw,
the torque required in inlbs is 1/31st of the preload in pounds.

Have you guys ever actually worked with a ballscrew and ballnuts,
applying preload ? I've set up 6 axes in the last few weeks.

Kim

On Tue, 2003-08-12 at 14:17, Carlos Guillermo wrote:
> Kim -
>
> Did you have a chance to read Hiwin's ballscrew app notes? You
> can find a copy here:
> http://www.ruchservomotor.com/PDF/H_Ballscrews(full).pdf
> There's an equation for "preload drag torque" on page 28 that you
> may want to study. We're all trying to tell you the same thing in
> different ways, but maybe this equation will clarify things.
>
> Regards,
>
> Carlos Guillermo
> VERVE Engineering & Design
>
> -----Original Message-----
> From: Kim Lux [mailto:lux@...]
> Sent: Tuesday, August 12, 2003 12:44 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO] Does this make sense? was Re:Bent
> Nookballscrews ?????
>
>
>
>
> > But, I am totally convinced that putting a heavy preload force
> between two
> > ball nuts by some spring-like mechanism will not cause a torque
> load
> > on the screw of the same magnitude as delivering that same force
> to
> > an external axial load.
>
> It absolutely DOES ! All I have to do is tighten down the bolts
> on our
> 2 ballnut setups and the friction goes way up. I've set up 6 axes
> in
> the last few weeks, so I think I know what I am seeing. And this
> isn't
> the difference in the ballscrew lead pitch either.
>
> > If Mr. Lux would care to drop by my shop, I
> > am pretty sure I could throw together a demonstration of this in
> a couple
> > of minutes that he would be absolutely unable to refute.
>
> Sorry, I've seen the opposite in our shop.
>
> > Jon
> >
>
>
>
>
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Kim Lux <lux@...>