Re: Ball screw adjustment?

I talked to Rockford today, and they quoted $411.50 for the 3/4"
preloaded nut for the precision screw, which gave me pause. I'm
looking for other options before buying 3 of these plus the screw
material!

Allan

--- In CAD_CAM_EDM_DRO@y..., "Doug Harrison" <prototype@c...> wrote:
> Allan;
> I went through this same exercise and determined it was easier to
get paired
> nuts from Rockford Ballscrew. My 3/4" preload nuts were $271 each.
>
> Lead error is both additive and periodic. I think the .004/ft claim
is
> somewhat misleading. You can easily compensate for consistant lead
error.
> Thread drunkenness (periodic error with a period of one turn)
cannot easily
> be compensated for, and this is the type of error you may find in
rolled
> thread screws. We found this to be a problem on a machine we just
finished.
>
> Doug
>
> ----- Original Message -----
> From: <allan_r9@h...>
> To: <CAD_CAM_EDM_DRO@y...>
> Sent: Monday, November 05, 2001 4:11 PM
> Subject: [CAD_CAM_EDM_DRO] Ball screw adjustment?
>
>
> > Hello Group,
> >
> > Has anybody on this list tried to "make" a preloaded ball nut from
> > two standard nuts spaced apart? Is this a practical idea for use
on
> > McMaster ballscrews with a lead error tolerance of 0.004"/ft.? I
> > talked to Rockford Ball Screws and found the price of the 3/4"
> > preloaded nut was ~6X the price for 2 McMaster regular ball nuts.
> > When "lead error" is quoted, is the error a linear additive, or
> > variable amount? Restated, is the 0.004"/ft error consistent on
the
> > next 12", or is it some other distance on the next 12"?
> > I'm getting ready to order the 3 screws for the GEM 500 machine,
so
> > looking for feedback. The 3D model will be placed on the Files
list
> > soon, along with the 5 axis trunnion table.
> >
> > Thanks in advance,
> > Allan
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> >
> > Post messages: CAD_CAM_EDM_DRO@y...
> > Subscribe: CAD_CAM_EDM_DRO-subscribe@y...
> > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@y...
> > List owner: CAD_CAM_EDM_DRO-owner@y..., wanliker@a...
> > Moderator: jmelson@a... timg@k... [Moderator]
> > URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> > bill,
> > List Manager
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >