Re: Ball lead screw backlash problems

> Paul, Are you sure it isn't in the endplate bearing? .004"

backlash is alot for a ballscrew. If someone installed standard ball-
race bearings instead of dualrow angular contact they will more than
likely have endplay.

Ron-

I think (and I hope) you could be right about the endplate bearings
causing the backlash. If I tap the end of the Y screw with a rubber
mallet I can move the table through the backlash zone, so its
looking like it could be a worn bearing or not enough preload.
Apparently its a good idea to upgrade these bearings when ballscrews
are put in, so I'm going yank it a apart, check these bearings and
the preload and replace them with better grade ones if they seem
worn.

They have some improved bearing numbers in the installation notes at:

http://www.rockfordballscrew.com/manual.htm

Also if anybody is looking to buy ballscrews for a Bridgeport, take
a look at the Rockford ones in the above link, they have adjustable
preload in the ballscrew nuts, while I believe the ones from HiWin
(which I think are the ones I have) are not adjustable.

Paul T.