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Jon Elson
 
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Artemia Salina wrote:

On Wed, 17 Aug 2005 16:14:27 +0000, Pete wrote:



This machine also has .30 backlash on the X axis. Any tricks to repair or
improve this?



I guess this miller is a Bridgeport clone, and so I'm not familiar with
any anti-backlash adjustments it may have because I've never owned one,
but some other milling machines have adjustable feed screw nuts. The
setup is a pair of bronze nuts that are threaded on their OD as well
as their ID. They screw into either end of a collar which is anchored
to the saddle casting (in the case of the X-axis).

Bridgeport's scheme is the nuts are smooth cylinders on the OD, and fit in a
close-fitting bore in the yoke. The nuts can be split with a bandsaw
into two
full cylinders (not lengthwise). There is a wide-head screw that will
squeeze
the two pieces together, and a locking screw that keeps the big one from
moving. You tighten up the big screw until the leadscrew binds at the ends,
where the wear is least, then back it off a hair. The nuts are bronze,
and hard
as hell, so when the wear becomes significant, it means the screw is worn,
too.

The X axis adjustment can be made with a flashlight and long screwdriver
without taking the machine apart. Newer machines come with the nut already
split.

Jon