Works perfectly in Y but not in X

Hello! I have built a Primo to replace my old, very hastily and badly printed Bulky. It is working pretty good, very much better than the Bulky, except for one big problem. The X axis is chattering and “binding?” like crazy. Y direction is working just fine. I’ve gone around feeling some bolts and tightening, but the problem stays. Does anyone know any specific parts to inspect? Currently working in acrylic at 200mm/min. Here is a video

Here is X finish (after finishing pass)

Here is Y finish (after finishing pass)

Thank you!


That sounds pretty close to my MPCNC that I’m finishing up. I have bearings in the trucks that don’t make full contact with the pipe as its moving around.
Try moving the core into the center of your workspace and feel all of the bearings in the trucks. Make sure they are all touching the pipes and cannot freely spin.

I’d also check the rigidity of your tool mount.

It’s “Burly”, not “Bulky”. No body shaming here, dang nabbit…


Will check out, thanks! Didn’t think about the trucks.

I checked it a couple days ago and tightened it until no flex at all could be felt in the spindle.

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