A350 - Not printing perfect circles

Hi Iv been using the machine quite a bit lately, and one of my new projects I need to print a couple of round buttons and there housing.

When I did this I found that the sides of the button were flattened almost as if it had a flat side to it in the Y direction.

I tried messing around with different settings and speeds, but this didnt work.
I also tried orientating the button 90 degrees to see if it was in the model and that didn’t change anything.
Finally I went and used Cura to see if was the slicer and its still doing it.

So I have no idea what to do or look at now? Has anyone else had this?
Is there some sort of tightening that is needed to be done like on a belt dive machine? (I know there are not belts but something else maybe?)

Some pics to show what I mean:

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Before anyone is able to give an answer, we need more information, like what speed you were printing at, etc. and if it was just this print or multiple others, what direction is it happening on? X,y?

Sorry I forgot to add those details:
So I have tried doing the preset Normal Quality, High Quality and also a manually edited High Quality. all of them have the same results. (i now have 15 deformed buttons almost exactly the same just differing layer height and infill density).
I have also tried using a raft as I was wanting to check if it was something to do with bed adhesion. (no luck)

For the Filement, Im using ESun PLA+ and have tried 3 print temps

  1. @205 as per the standard SM preset
  2. @215
  3. @230

From my tests the settings have had minimal change to the button.
Every time it happens its alway the left and right side of the button in the Y plane.

If theres any more information people would need please ask always happy to supply.

@SophieSeal k it’s definitely not adhesion if it’s happening on the same axis regardless of orientation of the model. Have you upgraded firmware lately?

Also can you do another one but don’t remove it from the bed and take a picture of it while still on the print sticker with it still on the heated bed? It’ll give a better picture of what might be going on. Unless the first pics are exactly that, that is.

Thanks @Artezio, the first picture is exactly that. Below is the same photo a bit further out, with two side by side, and one orientated 90 degrees clockwise Luban. (FYI the stripes in the blue painters tape run horizontally).

If it would still help I can print another one or set of two. and leave them on there this time. If so what settings would you recommend or suggest I do?

Thanks again :blush:

I have noticed the Snapmaker is a bit noisy when doing circular moves. I haven’t tried printing and measuring discs but that is a good test, I’ll give that a go later.

Assuming extrusions/e-steps and linear advance are calibrated, my initial thoughts would be:

  • print a larger disk (2-3x diameter) and see if that is round: if yes, then it is specifically the smaller diameter that is giving the trouble. That doesn’t fix anything but it is good to know :slight_smile:

  • try reducing (by 50%) and increasing (100%) the print speed. There might be a sweet-spot for this type of movement in the stepper motors. It sounds like you already did this, but a picture of the and fast ones wouldn’t hurt if they differ at all.

  • look into acceleration calibration (Teaching Tech Calibration: Acceleration Tuning. I found this to be of minimal use during calibration (the built-in settings were pretty optimal) but using your discs as a test print might provide clearer results when changing values.

  • watch the print and see if there is a seam being printed on layer change. On a small enough disk, this could appear as a distortion in the circumference rather than a clear seam.

I volunteered to print some buttons, so I’m kind of curious how to resolve this.

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If the flat spot on the side is aligned with either X or Y then it’s likely backlash from a loose bushing in the linear module.


I had this problem… got some videos on it if u search my history.

Linear module was loose.

Try swapping one an x and y around. it will be noisier probably. Video tape the slop and email support@snapmaker.com

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I was just thinking about backlash when I was downstairs preparing the next round of calibration tests.

At some point I am going to do the X-Y-Z steps test (https://teachingtechyt.github.io/calibration.html#xyzsteps - more to confirm accuracy of the current setup rather than trying to fix anything. I don’t think X-Y-Z would have the problems shown (resumably the error would be on all axis moves, meaning distortion on both sides of the disc), but backlash certainly would.

Installed the Cura Calibration Shapes plugin. Very handy, and includes a basic cylinder which I have scaled down to 10mm. Just waiting for the latest retraction test to finish.

@brent113 i was thinking backlash as well. Just wanted to make sure all information was present (which came after I fell asleep lol) before jumping to any conclusions.

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Printed a couple of 10mm cylinders at different speeds and temps. Solid, reliable circles - except for the seam that I mentioned being a possibility.

So yeah, might be the linear modules. Can this be measured with G425 and then compensated for with M425 on the A350?

Yea, I had that exact shape circle on the laser because the x axis crashed and loosened up. Had to disassemble and repair by following sdj’s guide

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@edf Thank you Ill give this ago today and try and print out some different sized test disks and also try doing some different speeds.

Ill post my results once done. Thank you :smiling_face_with_three_hearts:

@MooseJuice Thank you iv just checked my print head and it has some quite significant play/ wobble in it which Iv never noticed.

Can I ask if SM asked to see anything specifically as I don’t want to have to dismantle the whole machine and enclosure to move the axis around if i don’t need to at the moment lol


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Yeah I mean i would just video tape the play for them to see. Upload a link to it on t his thread, then send them an email saying you have this problem and direct them to see the video here. thats how i handled it anyhow and it worked well enough.

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Hi Sophie, if you try to use the laser module to engrave a circle, will it be round?
It seems that the issue is related to one of the linear modules. Try to swap X-axis with Z-axis.

Hey all, sorry for the delay in getting back, I have finished doing some more prints of larger circles as well as also taken a couple of videos of the play in the print head. If people have any other suggestions on a fix or the issues always happy to try. Ill also get in contact with SM.

Hi thanks @Tracy Ill try the laser module now and post the results shortly.
As I have the A350 in the Enclosure and not a lot of work space in my office atm I would prefer to reserve dismantling everything to making the axis swap for a last resort thing or unless its something that needs to be done as evidence for SM.

Thanks :smiling_face_with_three_hearts:

@SophieSeal your carriage in the x axis rail is a tad loose, but I’ve definitely seen far worse. I don’t think it’s related, especially since the circles stretch along the y axis.

I know exactly what you mean… especially about the enclosure lol. I have my Snapmaker and my huge desk in a spare bedroom meant for a single bed and a small tv.

@Tracy Iv just tested the laser and the circles come out fine.

So from the tests I think whats happening is that due to the play in the module which means it rocks back and forth, when 3D printing due to the extra force of extruding onto the heat bed, when the plate moves in the y direction it also moves the print module(printing head) slightly so that its out of position.

Would the next step be to swap the X axis for one of the Y axis and see if this solves it?