Re: [CAD_CAM_EDM_DRO] Re: Two Ballnut adjuster fitting?": anti backlash
Posted by
Kim Lux
on 2003-06-25 08:00:23 UTC
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
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.
>
>
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--
Kim Lux <lux@...>
Discussion Thread
Torsten
2003-06-24 22:03:51 UTC
Two Ballnut adjuster fitting?
mayfieldtm
2003-06-25 07:47:29 UTC
Re: Two Ballnut adjuster fitting?
Kim Lux
2003-06-25 08:00:23 UTC
Re: [CAD_CAM_EDM_DRO] Re: Two Ballnut adjuster fitting?": anti backlash
Dan Mauch
2003-06-25 14:50:32 UTC
RE: [CAD_CAM_EDM_DRO] Two Ballnut adjuster fitting?