My conduit looked the same when I first built it (common look after the plating process) and I took some fine sandpaper (~400 grit) and lightly sanded all of the rails. The other thing to check is making sure you do not have a bearing riding on a conduit seam. I had one stick that had a somewhat pronounced seam so I made sure I rotated that away from a bearing surface.
I have not fully run mine after making the inner rail stay parallel to the outer rail on my Y axis. I nicked the wiring harness and it cut at least mostly through the green wire. I was hoping to try a repair on it today but my schedule did not allow. It will now be a week before I can get to it again.
I did find that I needed the belts “tight” to reduce the shaking as well.