Re: [CAD_CAM_EDM_DRO] Re: Two Ballnut adjuster fitting?": anti backlash

I don't know if that is the best way to do it.

We are mounting 2 Nook 3/4" ball nuts in an anti backlash setup. We are
mounting one ball nut solidly to the plate attaching to the table. The
other ballnut mounts to a small plate that attaches to the first plate
with 2 x 3/8" fine thread bolts. We preload the ball nuts against each
other by tightening the 3/8" bolts. The nice part about it is that we
mounted the bolts as studs and with the use of nylock nuts we can adjust
the preload without disassembling anything.

The things I don't like about that antibacklash setup are:

a) only a few threads hold everything together
b) the adjusting thread is fairly coarse, ie 16TPI for the 3/4" ball
nuts
c) preload cannot be easily adjusted once the machine is assembled.
d) I don't like using a washer for preloading as the loads on the
ballnuts (static and dynamic) can be considerable ie several hundred to
600 pounds, depending upon the strength of the servo motors and gearing.

Our machines are used in production settings, so the usage will be
considerable and minimizing downtime is important.

Kim

On Wed, 2003-06-25 at 08:46, mayfieldtm wrote:
> Here is a Web Page that shows how to machine
> an Anti-Backlash Nut for Ballnuts.
>
> http://www.mmanrow.20m.com/anti_backlash_nuts.htm
>
> On my Browser, some of the Plans are hidden under
> the Photos. Needs a little hacking.
>
> Tom M.
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Torsten" <torsten@g...>
> wrote:
> > I am trying to save some money by making
> > a Backlash free Ballscrew setup with two
> > regular Ballnuts.
> > Now I need to design a adjuster fitting that
> > will go inbetween the two Nuts and allow then
> > to be adjusted to take up the backlash.
> > Preferably also with some spring action to
> > account for possible pitch errors on the screw.
> > May first attempts would probably work but
> > they are somewhat complicated and timeconsuming
> > to build.
> > Has anybody figured out something that works and
> > is resonably simple?
> > Any Ideas wellcome.
>
>
> 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@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@..., timg@...
> Moderator: pentam@... indigo_red@... [Moderators]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
--
Kim Lux <lux@...>