Hello everyone. Maybe someone can tell me how to solve the problem of printing on A1 mini. Models show bad lines.
I use PLA Basic filament from Bambu, but I also tested others and it was the same. Calibration of the device did not help. Where to look for the problem. Filament isbdry. I will add that I am a beginner in 3D printing.
Hi! You can’t send the screenshot due to you being “new”. It’s an anti-spam measure. Annoying but necessary.
As for your problem, try wiki first:
https://wiki.bambulab.com/en/knowledge-sharing/common-print-quality-problem
As for forum problems: Understanding Discourse Trust Levels
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This is the problem @Artur_3D is experiencing:
@Olias - You’re amazing where it comes to troubleshooting and your posts are full of knowledge. I honestly hever seen such errors, what should @Artur_3D try to troubleshoot? Looks like some z-issue.
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Typical sign of step loss, this can occur if there was something blocking the movement of the print head at the point of the shift. What exactly was causing the step loss I can’t say, the battery on my magic crystal ball is not working anymore and the printer/print background information from your side is rather scarce.
Other cases like that are often related to aftermarket add-ons which caused interference with the head movement during color changes or filament refill changes. Others are part warping and/or poor bed adhesion, print area going into the exclusion areas,…
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I don’t think I can improve upon @Panamon_Creel analysis.
There is no mystery here. Something is interfering with the smooth flow of filament as noted that these lines seem to be at the layer level.
The top three things I would investigate:
- AMS unit snagging the spool.
- Belt cleaning and maintenance to ensure that the nozzle is moving freely.
- PTFE tube inspection to make sure the tube is not snagging and/or properly inserted.
Also this opening statement is suspect:
If I had a dollar for every time someone made this claim… 
Here’s the litmus test of drying.
- What was the weight of the spool before you dried it?
- What was the weight of the spool after you dried it?
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thank you very much for your answer. I will check and test everything you wrote.
Hello. I checked yesterday:
-checking the condition of the PTFE tube
-checking the unwinding of the filament spool
-I cleaned and lubricated all axles
-I did all the calibrations
-I cleaned the nozzle
-I used various filaments (including brand new ones)
-I cleaned the PEI table
-I tested various models on which there was no problem before
The problem is still visible.
Do you think that installing a news hotend might help?
These issues are not typically associated with a worn or clogged nozzle. While they could be, such problems are usually linked to blobs or “zits” on the wall. A clogged or inadequate nozzle causes uneven filament flow at random. However, your examples show that this is happening at specific layers, suggesting that as the layers change, something is affecting either the filament flow or the Z-axis motion. As @Panamon_Creel mentioned, this could be due to step loss, pointing to a mechanical issue in either the rods or belts.
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To test this theory, I recommend printing primitives in separate prints. Start with a cylinder primitive and scale it to simulate the volume of your test models. This will allow for a very consistent flow, as the slicer handles it, and eliminate any issues caused by the model geometry. Then, repeat the process using a cube primitive.
Let me provide an example. I was demonstrating a method to do a clear side-by-side comparison of two different filament manufacturers. These images show that changing the filament mid-print to another manufacturer proved that in the first example the formula was obvious different while the second set of two spools, the formula was identical, despite the different brand names and spools. This is a useful diagnostic trick that you can employ here to verify that the mechanical movements of your printer are sound.
Example of two primitives with filament change using pause command:
The difference is stark. Most importantly, you can see a smooth transition as well as a color and reflectivity change, proving that the model remained intact and the settings stayed the same, with the only change being the filament formula.
Examples of two primitives comparing filament of different brands but suspected of coming from the same factory
Now compare that with the example I used with two different makers. In the two on the left, you can see where I paused the filament and swapped. The seam is obvious, but the color and consistency between the two manufacturers proves there was no difference in formulation. The model on the right was my control: it printed using a single spool source with no pause or swap, just to illustrate that it wasn’t the model causing the seam.
FYI: This also illustrate poor pressure advance calibration in cube example. Those ripples should not be there in a well tuned profile but I deliberately used the PLA Basic Generic factory profile so that everyone else could easily reproduce my test.
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BTW: The full post with examples of the original study can be found here. So you think your high priced fancy-schmancy filament is the the best?
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This could help but on the back of your hotend assembly there are 4 screws the connect the metal part to the little black block check the back and make sure all the screws are nice and tight. Link:A1 series printer extrusion abnormal troubleshooting | Bambu Lab Wiki
If you’ve done that try retightening the belts there’s a guide that bambu offers that teaches you how to do it. link:A1 Belt Tensioning | Bambu Lab Wiki
Hope this helps
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To throw in one more thing. Make sure the z screws are clean. Oh, and lubed
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The others are right about the Z verifications.
I believe the term for this is officially called " Z banding " and down this rabbit hole you should head a bit.
Here is an alt topic discussing similar (but worst) banding issues and their fix.
As your other lines look good and it’s only a few, might not need a new belt but it suspiciously might be the culprit.