Hello everyone,
I urgently need your help with a persistent printing issue!
I am struggling to get one specific corner of my 3D print clean. As you can see in the pictures, one corner is perfect, while the other looks messy and flawed. This is the corner that the print head approaches second—exactly the spot where the nozzle is currently positioned in the fourth image from the slicer preview.
I am printing with dried PETG HF and have already tried the following steps without any improvement:
- Speed: Reduced to 120 mm/s
- Acceleration and Printing Speed: Lowered
- Layer Height: Adjusted
- Printing Temperature: Reduced from 245 °C to 235 °C
Unfortunately, none of these changes have led to an improvement.
I sincerely hope you have some tips or ideas in store on how I can solve this problem. Thank you in advance for your support!
Have you calibrated the filament for pressure advance and flow ratio?
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Yes, I’ve calibrated everything. I just tried again with an outer wall speed of 20 mm/s. That didn’t work either. At the moment, I’m stuck and would appreciate any suggestions. Thank you.
I changed the wall order from inside/outside to outside/inside. Still no luck.
I have found good improvements by enabling “wipe on retract” with all PETG’s.
I also usually use the “Generic” PETG fan settings and lower speeds although the latter may be me being overcautious. I use 80mm/s for PETG Basic, 120mm/s for PETG HF.
Finally, what printer are you using? Several users are struggling with PETG on the P2S atm. Unfortunately, the root cause is still a bit of a mystery.
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Thank you so much for the information. I will try it and report back. I have a P1S. Thank you.
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Do you have the 120mm/s everywhere? For exterior and interior walls, and for infill? Or only for the exterior wall?
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Yes.
I think I am far to conservative with the HF but I prefer to have one good print a day to two bad ones.
So I usually set all printing (not travelling) speeds to 120mm/s when using Bambu PETG HF on my X1 and Qidi Plus 4.
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PS: Just remembering that I have seen gaps forming away from the seam before. Now if I could just remember how that was solved… I think it was related to a really good Flow Dynamics calibration being needed (obviously) but also rapid accelerations. In my PETG Basic work, I use 25% of defaults for acceleration.
Another item you may want to look into using the preview is “Detect thin wall” in strength and line width (using the Arachne wall generator can help somewhat). I can not be certain if these relate to the defect you are seeing, but you may be able to spot differences already in the preview.
Edit: Here’s a detailed description on the different wall generators just in case you want to dig a bit deeper.
Introduction to wall generator | Bambu Lab Wiki
Another guess. Are your seams located in the area of the issue? You could try setting the seam location someplace else (I.e. back).
So, I tried your suggestions. I printed everything at 120mm/s, recalibrated the filament, adjusted the Z-seam, and set it to random. Nothing worked.
But I’ve found the solution now.
I ran the part cooling fan at 100% on the lower layers where I was having problems.
It’s not perfect yet, but it’s much better.
Thanks again for your help, and if anyone has any other ideas, I’ll run some more tests.
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