Quote Originally Posted by ger21 View Post
My guess would be the nut is not aligned with the screw mounts, so the screw gets tighter as it gets closer to the ends. You can check by removing the motors and turn the screws by hand, to see if they get harder to turn near the ends.
I'd loosen the screw mounts, then move the gantry all the way to the end, and tighten them back up. Do this at both ends.
Hopefully there's some adjustment
Hey Gerry,
Here's the update. I'm not sure if we did this correctly.
I've attached a diagram of what we did numbered below, which I hope helps visually & not make more confusing

1. we removed the motors
2. moved the gantry manually using wrenches to turn the nuts at the opposite end of table from the motors. Moved little by little, but seemed okay.
3. disconnected anti-backlash, cleaned thoroughly, there was some build-up. Gantry slid easily from end to end w/ one finger while disconnected.

Should we have taken the coupling part at the motors off & moved from that area?

Notes:
At 60% jog it seems to move fine from end to end, but if we set a zero, then move it from there a bit and press "go to zero" it binds up instantly.
At 80% jog it still racks starting at the +/- 1/3 point

I hope I'm explaining things correctly, I really appreciate your help so far!

Have a great weekend,

Simon