Loose Y-axis ballscrew

[funkstar]

Hi
I have been monitoring some 0.04mm backlash in the Y-axis on my 86-triac. Since I have shimmed my X-axis to now have a much better 0.004mm backlash I naturally thought that this was the case for the Y-axis too. So I made some shims and took the whole thing apart and then got the whole thing back together and at the same time tighten the wedges for the axises.
Now I was measuring 0.1mm backlash. Crap!!
After some headscratching I put a dial-indicator to the exposed end of the Y-axis ballscrew. And althogh it is kind of rough surface there I could clearly see that the whole ballscrew was moving about 0.1mm when changing direction when jogging the Y-axis.
So, question: has anyone ever had this issue and if so did you manage to fix it? I have no more time tonight to look at it but I have a bad feeling about this one. Is there a way of tightening the ball bearings that support the ballscew or is it a whole new setup that is needed?

Thanks

Per

[Martin]

You should be able to tighten the Tab nut up. You will need to push the tab on the washer back first.

[funkstar]

Thank you Martin.
Behind the timing pully there was the Tab nut. Tightened it one tab and got it all back eventually (its not easy access to say the least). Now I measure backlash around 0.003mm which I am really happy with.
And I can tell the difference in the machine, it is much smoother and silent when cutting. Cool.

P.-