Z-gantry bearing resistance?

Hi all,
Just wanted to start buy saying thank you to all involved in the production of the long mill.
Can’t wait to use it. :grin:
Now my question is:
How much resistance should be on the z-gantry bearings?
During initial assembly, the resistance on the z-gantry plate felt a little high when I tried to push it along the y-gantry plate.
If I tilt the y-gantry plate into a vertical position, the z plate does not slide at all without “gentle persuation” from my hand.
To me, this feels too stiff and will lead to premature bearing failure.
I tried to realign the x-gantry plate rails for a smoother run but the hole tolerances for the little bolts holding the rails in place are so close, that there does not seem to be enough room for adjustment.
When all of the bolts are loosened off the z-gantry slides beautifully.
What are other people’s experiences/opinions on this?
On a side note, a couple of the small bolts that hold my x-gantry bearing rails in place, arrived over torqued during initial assembly and the threads were stripped off of these bolts. Please be careful if you do loosen the bolts for any reason, that you do not overtighten them.


@BenW we assemble the gantry assemblies in our office because they’re very finicky and only ship them if they pass our smoothness inspection. If your gantry is binding as much as you say, it’s possible that it might’ve been knocked around too much during shipping.

If you feel that you can fix the assembly yourself, I can try to walk you through the process we follow to get it running smoothly, but if not then I’d be happy to ship you a new one.

Hey Chris,
I am more than happy to sort this out myself but your technique in aligning the rails would be great.

I apologize, I didn’t get back to you on this Ben. Do you still need the directions?

Yes please Chris. I have assembled the gantry but it still feels a little bit stiff on its rails. You assembly technique may very well remedy this issue.

I put together this instructional picture for you. I hope it help to make your gantry assembly run more smoothly: