Y-axis excessive Wobble / See-saw

Hi all,

Having issues with the Y-axis… Started a 10hr print on my snapmaker a350 last night and part way through the print noticed severe wobble / buck / see-saw on the build plate and at a guess this was around 1 - 2mm at the outer edges. I havent noticed this before and its something I would have noticed so im assuming its an issue which has gotten worse over the last few prints. I’ve had various issues in the last few prints with the linear modules screeching (some light oil sorted that) and had issues with the dust seals making a snaping noise which retensioning them corrected that. This seems more of a design issue with how and where the bed is fixed to the linear modules and im assuming wear & tear will only make this worse to the point its unusable. The print was an adaptor for a friends dumbells bars to accept olympic weights done in PET-G with a build plate temp of 80 degrees C. The print started fine but as it progressed the center hole has become oblong by around 2mm along the Y-axis . I’ve attached a link to the video and I apologise for its bad focus but it was difficult to video it. https://youtu.be/nyUkSZG3chQ

I’ve noticed another post on the form where someone added extra linear module to correct this wobble / see-saw but it seems like an extreme measure to correct this. Any help would be appreciated


Pull off the bed and platform and see if you have play in the brackets on the linear modules.

What were you oiling? There isn’t anything that should be oiled on the SM, and nothing to lubricate without removing the dust seals.


Thanks for the reply.

Completely stripped down the machine this evening.

Opened up each linear module, regreased the worm drive and re-tightened the dust strips.

Checked the bed and all modules for tightness and play, everything was fine with no slack screws .

Re-aligned both Y-axis making sure they were parallel within 0.01mm end to end.

Double checked tightness of everything and just started to print the other adapter so i’ll have to wait and see if the same issue reappears. But it’s already noticable that the modules are quieter after regreasing.

I lightly oiled the dust strips as they were definitely causing noise, i found others had done so on the forum hence why i tried it.

Just having a look at the bed whilst its printing, there is definitely see-saw on it even at its low current speed.

Assuming its a backlash issue with the linear modules and their worm drive after seeing the internals.

The play on the bracket assembly is set by adjusting the height of the two rollers on the assembly. Up/down and rotational or axial play is adjusted by these.
Wear or looseness on the lead screw to bracket assembly connection would show up as left/right play (holding module horizontal).

1 Like

Thank you very much for your help! I did notice the rollers and adjusting screws but thought it looked like some sort of thread lock (Green Goo) was used on them so decided to not disassemble the modules more to adjust them. If your telling me that by adjusting these rollers it will take the left/right play (see-saw) im having thats great news and im sure this post will help many others. By any chance do you have any photos of the bracket assembly and adjusting procedure?

On a side note, whilst regreasing the X-axis module I noticed both rollers were showing signs of rust. None of the other modules rollers had this issue.


Surprised that you had rust from what i saw when i took mine apart. Guess it depends on your environment. Lightly costing with the grease thats already there.

My adjusting guide:

(Use at your own risk. Until SM actually comes up with an official procedure, I hope this helps people)

1 Like