Backlash adjustment

Hi Dear All,

I have a backlash problem in X axis on VMC.
I've checked with using dial indicator and found appx 0.5 mm backlash!!!!!
When I programmed (in incremental mode) X+ 0.5 ; X-0.5 ;.....the ball screw was rotating but the pointer on dial indicator was not moving...the exact backlash found 0.55 mm...
Now I am looking to short out this issue and searching for which part to be changed to make this machine run as usual..
Thanks,

Next up... Put an indicator on the end of the ballscrew.. I bet it moves a half mm..

Thrust bearings, though they usually would be seized or incredibly loud by that point.. Loose couplings from
the motor to the ballscrew would be my guess.. I've had that happen a few times.. Something could also be
loose where the ballscrew/motor mount..

99% chance the problem can be fixed by tightening a set screw or a bolt.

If you really have 0.55 backlash in the screw, it is toast and should be replaced! Most controls can only comp for about 0.25 mm and even at that it is sketchy. Our change trigger criteria is 0.15 mm. That is not when it's changed, that is just the trigger point to get it scheduled. In all of our years of tracking this stuff, after about 0.15 mm, the wear rate increases significantly. i.e. you may get 600,000-800,000 cycles out of it to get to 0.15 and only get 100k more to get to 0.25 mm

I have observed that lubricating pipes are blocked.
Axis moves X+ direction with normal noise, but in X- direction makes growling noise..(abnormal sound)...
Now I would like to change the ballscrew set.
How can I change this? i.e. I have to remove table or is it possible without removing it?

You need to provide make and model of VMC, they are not all created equal. More than likely, yes you will have to remove table to access the nut
unless there is a way you can move table to the end and get to the mounting bracket for the nut.
You can not just buy a new ball screw and shove it into an old nut.

As mentioned above, you might get lucky and just have to replace the thrust bearings/motor coupling and be good to go.

Also, since you have a known problem with the lube system it would be safe to assume that you need to address the entire lubrication system.
If X is blocked there is a good chance Y and Z are not far from it as well.
When ordering your parts go ahead and order new orifices for the lube system, if I am not mistaken, they have different sizes so as to regulate lube flow so pay close attention to that.

If you could remove the way covers and take several pictures of it that would be extremely helpful.