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

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
>