Methods of setting backlash adjustment

[ashesman]

I setup my backlash again the other night. The number I ended up with for backlash was 0.0025mm on all axis (one tenth for you imperial types). This seems like a really low value for an old machine with 1500 hours on it right?

I tried a few different methods with a variety of dial gauges. I was surprised to see that the Haimer and other 0.01mm dial gauges were not responsive to changes in direction below 0.01mm, but would respond to changes of 0.001mm in a continuous direction. Whereas the micron gauge was great and would respond to changes in direction below 0.001mm.

Check out the video below to see the final result. Each division on the gauge is 1 micron (less than half a tenth). I am clicking the MPG back and forth one micron steps.

How do you guys do backlash adjustment and what sort of numbers do you normally see in used ball screws?

[martyscncgarage]

You've seen how Marc does it?
http://www.cncsnw.com/Lashhowto.htm

[ashesman]

You've seen how Marc does it?
http://www.cncsnw.com/Lashhowto.htm

That's pretty much how I did it but without a program. I probably wasn't moving quite as far as 50" though. I didn't think to write a program. Although I would be too scared I would cock it up and mash my dial gauge!!!

I will do the test that way with a little program and see what the backlash looks like.

[JasonPORC]

Wow! Looks damn good to me.