760-22 x axis problem

[tstom]

I have a 760-22 that has a tight x axis Probably a year maybe more ago Machinetek had posted about shimming the plates that go under the ways I did this and the machine ran great until a month ago I found the oil line to the ball screw broken and replaced it The mill ran good for about 2 weeks but the ballscrew is tight again I have also cleaned and regreased the thrust bearings on each end of the screw They looked to be in good condition

The ball screw looks smooth and shiney I guess I'm to the end of my knowledge which isn't all that far Any help would be appreciated

[machintek]

Back to square one. You do not know what the issue is so loosen the screws on the X axis keeper plates a turn and see if it frees up. Go from there.

George

[tstom]

Loosened the front keeper plate and tried to turn the ballscrew by hand it turned snug for a bit then freed up so I tried to retighten the plate and the screw got a little tighter but nothing like before I loosened the plate I can still turn it by hand
I cut a strip of .001" shim stock ,loosened the plate and inserted the strip between the way and the turcite plate on the left end it pulls out with slight resistance on the right end it will pull out but has a lot of resistance so I guess I have slightly less than .001" clearence I'm confused as to how the screw can free up so easily after it was so tight and then is still be free when I tighten the plate back up


Tom

[cncserveng]

your ballscrew could be damaged, it is not good practice to shim things unless you have measures the clearances. With a good axis it should be possible, without the motor, to turn the ballscrew freely by hand.

Good suggestion to put things back as they were originally and go from there.

[rmarchjr]

on all my 760's we can turn x & y by hand with motors off. i think your ball screw may be damaged, if its very shiny its prob worn.
I've heard they don't do well without way oil for very long.