Linear bearings sticking/jerking on 10mm smooth rod


#1

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?

Thanks,
Rockey


#2

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


#3

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?


#4

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.

Thanks,
Paul


#5

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


#6

yup - about a month ago…


#7

@brookshank @mjrice has them for sale on his ebay store - http://www.ebay.com/itm/231861642515, I just ordered one, hopefully its smooth like the rest of them :smile:


#8

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.


#9

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.