[CEStanley]

I need some advise. My Y axis moves more in the negative direction than the positive direction by around .015 inch. Here is what I am doing:

1 - I setup my 0-1 analog indicator and get the Y axis moving in the negative direction. When the meter reaches zero I stop the Y axis and change to the settings screen in Mach3.
2 - I tell Mach3 to move the Y axis -1.000 in the negative direction.
3 - The Y axis moves -1.0002 inches. Considered great!
4 - I change to Mach3 Program Run screen.
5 - I move the analog indicator to the other side of the table and get the Y axis moving in the positive direction until the meter reaches zero.
6 - I switch back to the Settings screen in Mach3 and I tell Mach3 to move the Y axis 1.000 inches.
7 - The Y axis movement is .985. Terrible!

This is all done with backlash set to zero and backlash taken into account before the meter is set to zero.

Anyone have any idea of what is going on here?

There is more to the story. I had the Y axis set to +/-0.0007. I had to dismantle the Y axis from the Mill to add a Y axis Home switch. I made sure the Y axis was free to move and tightened it up.

Any guess as to how I ghet more movement in one direction than the other? (group)

[CEStanley]

:idea:I found that the Y axis ball nut was lose. The play was causing major issues with the calibration of the Y axis. So I now have the Y axis tuned within 0.001 in one direction and barely noticeably in the other direction. So when I tell Mach3 to move the Y axis 1.000 inch it moves it 0.999 in one direction and just over 1.000 in the other (maybe 0.0002-ish)

I hope someone else reads this post.
C :stickpoke

Tired and dirty and covered in oil,