Hi CrazyIvan,
My machine is still stock apart from what I have done to it, I did have herrendous backlash when I first got the Mill but the brass nuts are somewhat adjustable. But there was a prob with binding in different spots up and down the length of the screw. As the pics of the X and Y drives are now the Pulleys are tension against the thrust bearings to elminiate all axial movement.
After a day of frustrating adjusting and testing I've finally got it down to .05mm to .1mm like you said its still better than manual milling anyday.
I will however when I wear these out convert to ball screws as long as my machine lasts long enough to make the new parts!! (I have no doubt it will)
How far along are you with your conversion?
Cheers,
Adam.
www.xasertech.com