Really weird print issue

Bambu Lab A1 Series Troubleshooting
1

I’m running into a really weird print issue. I’m not sure what setting could be causing this, but I’ve tried editing a bunch.

IMG_20250115_215139_652
IMG_20250115_215139_6521920×1446 59.7 KB

IMG_20250115_215227_358
IMG_20250115_215227_3581920×2550 65.4 KB

IMG_20250115_215232_609
IMG_20250115_215232_6091920×2550 89.6 KB

IMG_20250115_215241_395
IMG_20250115_215241_3951920×2550 144 KB

As you can see, I’m getting really weird cracking(?) issues on the support material, and the solid portion of the model is warping up near the edges.

3mf file used to print this particular sample:

TestLink.3mf (98.9 KB)

I’m using Inland green PLA for this print, which I have used successfully on this printer in the past.

I’ve also been messing with some other settings, which don’t seem to have effected the issues seen here.

  • Cooling fan - was previously at max, and a lower speed for this print allowed the solid portion to remain soft enough to prevent the toolhead from knocking the entire model off the bed
  • Room temp - has been increased, for minimal changes

I do not have an enclosure (and am not opposed to building one, although I have seen Bambu recommend against one). I am using an AMS, but I would not expect that to impact the issues I’m seeing here.

(Minor edit: removed a blurry photo)

2

I solved the issue, and want to document this not only for other, but also for myself.

The issue was a clogged nozzle. This can be identified by the voids in the print, and leaking filament after the printer stops printing. I assume the leaking is caused by the slow pressure release around the clog.

The final solution was to do a proper cold pull. It’s very important to ensure the nozzle is cool enough when doing the cold pull, since I had done several cold-pulls incorrectly by simply not waiting long enough, so the filament simply stretched rather than pulling out the clog. I recommend allowing the hot end to fully cool after cutting the filament (I let it sit overnight), and raising the temperature to 75-100 to soften the outside of the filament. Then perform the cold pull right away, before letting the heat fully penetrate the filament. This should help prevent the filament from stretching and leaving the debris inside the hot end.

2 Likes
3

How long should you wait when raising the temperature to 75–100°C to soften the outside of the filament