[rmachinist]

Hi
Question when I setup motor tuning for example Z axis has 5 mm ball screw and I have the driver set at 2000, so 25.4/5=5.08 then x 2000=10160 that's the number I entered for step per inch, but when I use a gauge block 3in. I'm off .009 and 2in. Gauge I'm off .006 off . All my axis are off some amount. I have very little back lash .0005 to .001 max .I'm using mach3 any ideals anyone on how to correct this?

[toddbeau]

You should move in one direction only to set steps per inch. For example move X +1, zero dro and move X+2 and then measure +/-2.XXX, this way you don't put any backlash into the measurement. If you're doing so then you're measuring the error of the screw, I think you can map in mach 3 but I never did, test a few spots on the axis.

[dazp1976]

Hi there.
So you're now close but it looks like it's still off by .003 per inch, yes?
Now you need to 'fine tune' the axis in Mach3 auto calibration section.

You will need something precision size on the table to do this.

I've never needed 'perfect' accuracy so never done it with mine.
There are loads of videos around showing you how to do it.

This should give you a rough idea on the methods:

[rmachinist]

Thanks