[emcodeckel]

Hi All,

Doing some measurements on a Fadal recently, I noticed that I could 'move' the table in X or Y direction by 0.01 - 0.02 mm while the machine was not under power (just by pushing manually against the table).
This doesn't sound good to me as this is not normal as far as I know.
Any idea what could be the problem and a possible solution?
I'm thinking it's the X and Y axis ball screws but can they be adjusted / tightened?

Any help is much appreciated

[rwskinner]

Check the ball screw thrust bearings. Those are prone to going bad. Some have liquid cooled ball screws and the coolant can leak and damaged the thrust bearings. Most folks bypass the coolant when the rebuild the bearings and seals. Then finally, wear in the ballnut/ballscrew, or loose components. Check the thrust bearings first.

[emcodeckel]

Thanks for the sift advice
Any pictures avaialble of good and bad situations so that I get a fair idea of when things are too bad?

[rwskinner]

I forgot to mention, a very easy way to check them without a tear down is to put an indicator on the end of the ball screw and then move the table back and forth manually. The indicator reading is the thrust bearing play.

The best place so to this, for the X axis, removing the left hand way cover, for the Y would be the cover nearest you.

Too much? Whatever you can tolerate.

[emcodeckel]

Thank you for this additional advice

Looking ahead towards a possible solution ....
Is there a way to 'tighten' the ball screws?
Or not at all and should they just need a replacement?

[rwskinner]

Depending how much wear there is. Sometimes they can be re-balled, sometimes reground and re-balled. That's what I did on 2 of 3 and on the 3rd one I just replaced it.
Start with the checking of the Thrust Bearings by testing the way I mentioned. Also, google Fadal Manuals. Tons of information in there and there is a section on checking the axis.

[DeanAustin661]

I think it's normal because if it's a gravity axis and the motor has a brake, it can't be pushed. Besides, 0.01 is already very small.