Linear bearings sticking/jerking on 10mm smooth rod


I started on the X axis of my kit tonight and ran into a problem that has me paused. The movement of the x-carriage is really jerky as if it’s catching on something. At first I thought It was a bad bearing so I started to take the x carriage bearings out to test them individually.

What I found was that the sticking/jerking only happens on one of the two 10mm smooth rods. All bearings travel well on one rod and all bearings stick/jerk on the other. I’m guessing the bad smooth rod is slightly out of spec and causing the bearings to bind.

Any advice about how I might be able to resolve this or get a replacement 10mm smooth rod, 370mm in length?



It sounds like the one is just out of tolerance, which you can’t really do anything about. Replacement on the way!


One of my Z axis rods is acting similar, and causing the printer to bind often when traveling up and down. Is it most likely the same issue as Rockey’s?


I’m having the same problem on one of my 370mm X-axis smooth rods. At first I thought the x-axis might just need to be lubricated but I finally got around to pulling the machine apart and sure enough one of the rods is pretty smooth and one of them catches and jerks like crazy… I also tried the Z-axis rods for fun and they seem to be smoother than either of the X axis ones. did not disassemble the y axis but it doesn’t have the same jerky movement problem the X was having.

Let me know where I can get a replacement for the bad rod.



I’m having similar problems (except on my Z axis rod). Did you buy a kit from @mjrice recently? I think he may have gotten a bad batch of rods.

+1 for the location to replace the rod from


yup - about a month ago…


@brookshank @mjrice has them for sale on his ebay store -, I just ordered one, hopefully its smooth like the rest of them :smile:


I got the new smooth rod very quickly (and some bonus filament, thanks @mjrice!!) The new rod went in no problem and the x axis now moves freely with no sticky spots - I measured the old rod with the calipers and it was really close to 10mm for the most part but has a few spots that are > 10.15mm in certain rotations.


Good to hear! I’ve started running every rod through a double LM10UU bearing (actually just an assembled X carriage) to weed out any out of tolerance rods, so hopefully this won’t happen regularly.