Axes issues - troubleshooting

Hi again,

We’ve been having plethora of issues with M300 Dual. Here’s another one. Printer has clocked in 4600h at the moment.

For many months we’ve been having issues with errors pertaining to failures of the device while performing various movement related procedures - loading/unloading, axes test most notably. The issues would come up with an error saying that there’s a problem with either X or Y axis optical sensor or (only lately) with an information that axes maintenance is needed. In general the extruder movement seems a bit too tough but I can’t really tell cause thatis the only printer that I have.

So, I finaly sat down to take care of it. Optical sensors are 100% fine. Firmware updated, no issues with extruder. I narrowed the issue down to axes misalignment. Here are two readily obvious issues:

  1. When extruder performs homing and goes to bottom left corner there’s good chance it gets stuck there and the engine has not enough power to move it resulting with X/Y sensor error.
    It’s not a 100% chance. Sometimes it performs a full axes test without being stuck. However, when it gets stuck it’s notably harder to move it from this position (power off), but then it usually moves sort of freely.
  2. When extruder moves directly along either axis there’s a small chance increased friction issue comes up and extruder stick-slips with a noise.

I’ve spent nearly 2 days disassembling and reassembling the whole thing, cleaning all the axes, cleaning bearings, everything and I’ve come to the conclusion that the 8 self-aligning bearings are at fault. 7/8 of them have hard time moving around, especially from the neutral position. The rotation is fine, but the yoke movement is obstructed. And I mean in some cases catastrophically! I cleaned them as much as I could from black residue, lubricated them and it reduced friction a bit, but not enough.

I also used the distance clips intended for axes alignment check. In general the top right and bottom left clips show a 2mm gap but even after fiddling around with the setup and reducing all gaps to 0 the very same issues persisted. Only then I decided to disassemble the printer.

I think this is the root cause also because there’s a clear clicking sound then I move the extruder around at midplane, which is probably made by the only fully working bearing when it aligns the axis according to forces acting on it.

Another thing that points to this being the issue is that the extruder exhibits the highest movement resistance at the 4 corners and moves more freely in the center.

Side note! Each of the 4 “big” axes plain bearings along the edges of the printers top comprise a housing and a single brass bearing. Is this normal or the longer housings (along front and back of the printer) should contain two bushings each? Cause it definitely looks like they should!

So I have two requests to you guys:
a) Have you ever experienced similar issues and what helped you out?
b) Could you please provide the numbers/source of those two catalogue items so I can buy them at some 3rd party and replace them? Because you do not offer them off the shelf…

Kind regards

1 Like

Hi Tommar,

since you have been dealing with these issues for several months - I would recommend considering sending the printer to Zortrax headquarters to carry out necessary repairs. Since the device has also done 4600 hours, it might be good to perform thorough maintenance to ensure the printer is fully operational (QC and geometry tests are obligatory before the device leaves our facility).

As for the bearings self-aligning in housing - rarely do they fail, but when they do you would rather hear a click sound, which does not affect the printer’s performance. But obviously, we would definitely take a closer look at them to verify what you have noticed.

When it comes to requested parts - these are service ones, so they can only be purchased from our support department. Sadly, we do not provide any part numbers.

Best regards,

Hi, thanks for reply.

Could you please PM me what the estimated cost of sending the printer to you would be? Let’s say all the self-aligning bearings (8) and X, Y motors needed replacement.

Kind regards

Hi Tommar,

please, contact us through the support form as requested. Our support agents will provide a repair estimate as well as prices of the spare parts. We cannot provide such information on the forum.

Best regards,

Hi Tommar,

I think I got the same problem as yours. Could I ask how you solved this problem finally? If you are interested, here is the video. extruder stuck – Google Drive
Much appreciation!

Kind regards


Well it all comes down to proper axis alignment. I can tell you what did the final trick but I can’t tell you if a bunch of things that I did before that had helped or not.

The final steps: Do the axis alignment in a specific way, do it thoroughly. Here’s probably the best guide: Belts Replacement in M Series 3D Printers | Zortrax Support Center

The sequence I did in the end was to:

  1. Loosen all the screws around axis - the setting screws for axis, blocks screws and self-aligning bearing screws
  2. Tighten the engine belts (required 2 people, one pushing the engine with bracket down, the other screwing it to the housing)
  3. Move the extruder to the base point (lower left corner), move it around a bit, tighten the screws in this order: 4 axis setting screws in this corner → 4 screws in blocks in this corner
  4. Repeat for each corner
  5. Move the extruder again to the base point, move it around and tighten the self-aligning bearing screws in this corner
  6. Repeat for each corner
  7. Loosen a bit each RIGHT-SIDE screw in each block, leave the left one tightened

Also check if loosening the setting screws that hold the bronze plain bearings in block the the axis helps out.

Hope this works out for you.
Best regards,


Hi Tommar,

Thanks for the reply! I got inspiration from your solution.
My problem was finally solved just by adjusting the location of the self-aligning bearings, as indicated in this manual Axes Maintenance in Zortrax M300 Dual 3D Printers | Zortrax Support Center, step 4. But the difference is, instead of merely grabbing the extruder and moving it around the housing, I used a wrench to change the position of the bearings a little bit, and the stuck disappeared.