Re: Retrofit Backlash

evening cnc dudes,

on some milling machines there are devices called gibs that are
utilized to compensate for wear and manufacturing tolerances.
the gibs are usually located under the table. some machine builders
set these at the factory then "run in the machine" as a kind of
lapping or breaking in of the ways and tables. try and see if your
machine has gibs and adjust them by putting an indicator on the knee
on the left hand side of the machine.crank or jog the x-axis to the
center and locate the indicator on the extreme left side of the x-
axis table,set the indicator to zero. physically grab the x-axis
table and push it towards the column. notice if there is any
indicator movement.pull the table away from the column and see if
there is any indicator movement.by doing this it will tell you if
your gibs need adjusting. according to my bridgeport manual there
should be about .0002" on a new machine, but in reality that seems a
bit tight.
i hope this may help you.

--- In CAD_CAM_EDM_DRO@y..., "grease122696" <george@f...> wrote:
> There preloaded ball screws. That's all I know. I have a freind
> helping me with this and he sent the yoke out to the company that
we
> bought the ballscrews from and they modified my yoke to work.
> It seems the backlash I'm getting is flex, because the yoke is
seems
> to be moving with very little backlash .0005 or less.
>
> --- In CAD_CAM_EDM_DRO@y..., "Dan Mauch" <dmauch@s...> wrote:
> > Out of curiousity did you buy the hiwin ball screws with the yoke
> for a
> > BP? If not how did you fasten the ball nuts to the yoke?
> > Dan
> > -----Original Message-----
> > From: grease122696 [mailto:george@f...]
> > Sent: Tuesday, March 12, 2002 10:47 AM
> > To: CAD_CAM_EDM_DRO@y...
> > Subject: [CAD_CAM_EDM_DRO] Retrofit Backlash
> >
> > I'm converting new Taiwan 9x49 knee mill to CNC using Ball screws
> and
> > steppers.
> > There seems to be .001-.002 backlash in the X, .001-.003 in the Y
> and
> > .002 in the z. It seems the backlash is coming from flexing . I
put
> a
> > indicator on the yoke up inside the casting to check the Y and it
> > seems to .0005 backlash to there but when I indicate at the table
> it's
> > a different story. I have the same problem with the Z. I
couldn't
> get
> > a indicator on the yoke to check the X.
> >
> > Anybody have this problem or have any suggestions.
> >
> > TIA
> > Geo.
> >
> >
> >
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