Sudden Printing Issue with X1C- Software or Hardware?

I ran into a sudden issue immediately after updating to firmware 1.08. A model that I had previously printed several times in both bambu and ovature PLA filament started printing with a nasty edge (see photos).


Since the Firmware was the new variable, I reverted back to the previous version, and got the same result.

Figuring my hot end needed to be maintained, I checked it and the thermal grease had completely dried out. I cleaned the parts, applied new grease (the little packet provided by Bambu), Same results.

Might be the nozzle? I replaced the hot end with a new one (only the nozzle/heatsink portion, I didn’t have a spare thermistor) this time using Slice Engineering Boron Nitride paste. Same result.

Yesterday I was notified that there was an update to BambuStudio. I updated and re-imported the model to a clean project file with the new version. Surprisingly, it was much better, but there is still a very noticeable dent in the model in the same area (circled below), so I didn’t consider it solved.

I tested a model that was very similar (but different proportions), and the original problem recurred with the original severity.

At this point, I’m unsure if this is a software problem, or a hardware problem. Since the nozzle is new, the only hardware issue that immediately comes to mind would be the thermistor, I have some on order from Bambu. However, since the software update -almost- fixed the problem that might be more likely?

I have tried printing at the preset .24 Draft and .16 Optimal settings in studio, on multiple types of build plates, with Bambu Basic PLA. The messy edge is surprisingly consistent, and messed up in almost the exact same way on each test.

Just now I rotated the model 180 in the slicer, the damage happened on the other side of the model (so both times on the same side in relation to the printer, right side if looking into the printer) so maybe it is a hardware issue?

Either way, I’m reaching the end of my limited knowledge on how to fix this. If anyone has any ideas, they would be greatly appreciated :slight_smile:

Thank you!

When asking for help, please provide as much information as possible about your inquiry.
Including pictures and detailed information about the print speeds, filament type and settings used will help get the appropriate solutions.

Have you got scarf seam turned on? I had a couple of models which don’t play well with the standard setting, turning it off helped (too lazy to fully set it up)

Thanks for the amazingly fast reply!

Scarf Seam is set to ‘None’, however the issue IS happening on the seam. I’m not sure if the seam stays in the same place if the model is rotated and re-sliced (I didn’t save the file from the 180 test)?

Doing a test now moving the seam to a different place to see what happens…just figuring out how, as I’ve never had to do that before :wink:

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I painted a new seam in the center of the model. The same issue happened on the same edge, but there are also errors on the new seam I painted (circled in images below). I’m assuming that painting added a seam, rather than moving the existing seam?



Either way, it appears to be seam related…

After reading around the forum a bit, I did a full factory reset…problem still persists :frowning_face:

Update, I tried printing another model, and it printed fine.

So thinking it may have been an issue with the step file getting corrupted or something, I exported a new step from the CAD project that created the model. The issue still remained, though strangely was only about half as bad (in the exact same area of the model).

Other models have been printing OK, but the seams are MUCH more noticeable than they ever have been before (recessed into the surface).

Does anyone have an opinion on if it is a hardware issue or a software issue? I received some spare parts from Bambu, including a full hot-end assembly, but I’m skeptical replacing it will help, as there was no difference after replacing the nozzle.

I’m also wary of trying more adjustments to my slicing settings etc. unless I get some solid advice because at this point, I’m just wasting PLA on test prints without getting anywhere.

Any advice or suggestions would be greatly appreciated, thank you!

Looking again, I can see this is more an overhang issue and maybe slowing down your outside layer speed could help.

The issue is when the nozzle comes around the sharp corner and suddenly slows down for the overhang, the slow down may be a bit too harsh.

The example above is exaggerated but shows the speeds and that corner where the green turns to red is the area I think is the problem. Transitions from 260mm/s to 40mm/s on that sharp edge.

Slowing down the outside speed to 100 or less so the transition isn’t so harsh would be my first trial. Alternatively rotating the model so its upright, but it will cause the bottom to sit on a raft/support that will be less clean.

Thank you for your thoughtful response!

I just tried those settings, and got the same result as previous prints. I do think it may be overhang-related, the visible seams that I mentioned were also happening on an overhang area (though not on a corner)

It’s also odd that I had printed the problem model at least 10 times with no issues whatsoever before this popped up (with the “.16 Optimized” default slicer settings)…

I’m trying a test now where I’m rotating and printing with supports. I’d rather fix the actual issue b/c I rely heavily on overhangs when designing (to avoid supports), but hopefully it might give more information to test it.

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A Few more tests…

I rotated the model in the slicer so the problem edge was perpendicular to the bed as @GenericUser suggested. The edge printed fine, so they’re likely correct that it is an overhang issue. I’m going to try slowing the outside speed down more dramatically next.

I wanted to see if it was consistent across the print bed, so I printed 2 tests
-one placing the model in the closest right corner, and a copy in the furthest left corner.
-one vice-versa (close L and far R)
In both tests, the models toward the rear corners of the plate printed fine, the ones toward the front (closest to the door) had the issue. The front left model was slightly worse than the front right.

The issue always happens on the rear right corner of the overhang shape. The other corners are always fine.

I researched seam settings and ran some tests with no positive results. I’ll start researching overhangs, but if anyone has any ideas, they would be greatly appreciated :slight_smile:

I turned outer layer speed and overhang speed(s) way down-

Issue still persists…

I think it’s significant that it happens at the front of the print bed, but not at the back (per my previous tests above). On my old ender, that would usually mean I would have to manually level the print bed.

I’ve obviously run Calibrate and Device self-test countless times throughout these tests, is there any other way to check and/or correct bed leveling on the X1?

Bed tramming via the Bambu wiki Manual Bed Leveling / Manual Bed Tramming | Bambu Lab Wiki is pretty basic. Moving the model to the opposite end and rotate 45deg might be worth a look, the bed mesh overall should only factor in the lower layers for the most part.

Have you tried outside wall order first?

Hmm, yea the issue starts happening a little bit up the model…

I’ll try outside first, but I was under the impression that’s not ideal for overhangs, since the outer wall needs to attach to the inner wall (could easily be wrong here)?

Thanks for the link! I’m a little wary to try it b/c it looks like I can make things worse but I’ll try to muster up the courage :slight_smile:

When you say “moving the model to the opposite end” I assume you mean to the location on the bed where the issue is the worst?

Thanks again for the replies and suggestions!

Bambu bed mesh typically works good to cover most scenarios, but in your case its good to do the tramming so you can discount that anyhow. I missed yesterdays post about your model placement, the back rear corner can introduce other factors as the PTFE tends to curve a lot, not sure if this is adds to the issue? Beyond that I’m out of ideas and hope you can make better sense of the mess to find a consistent print :slight_smile: