Nozzle Debris & Blobs on A1 with PLA Matte in Vase Mode

Hi everyone,

I’m running into a frustrating issue on my Bambu Lab A1 and I’m hoping someone might have some fresh ideas, as I’ve hit a bit of a wall.

The Problem: When printing in “Spiral Vase” mode with Bambu’s own PLA Matte filament, a small blob of material slowly builds up on the side of the nozzle. After printing for a while, this blob inevitably gets deposited onto the side of the print, ruining the clean single-wall surface. The rest of the print quality is perfect.

My Setup:

  • Printer: Bambu Lab A1
  • Filament: Bambu Lab PLA Matte
  • Slicer: Bambu Studio, using the “Spiral Vase” option

What I’ve Already Tried:

I feel like I’ve adjusted all the usual culprits, but the problem persists. Here’s what I’ve done:

  1. Lowering Temperature: The default profile is 220°C. I’ve tried printing at 215°C and 210°C. This seems to reduce the speed at which the blob forms, but doesn’t eliminate it.
  2. Adjusting Flow Ratio: I know the default for this filament is already 0.98. I have tried manually setting it lower, down to 0.96 and even 0.95. Again, maybe a slight improvement, but the blob still eventually forms and detaches.
  3. Reducing Volumetric Flow: I’ve tried lowering the “Max Volumetric Speed” in the filament settings, thinking it might be a pressure issue, but this had no noticeable effect on the problem.
  4. Cleaning: The nozzle is cleaned externally before every print, so the surface is clean.
  5. Speed: I have tried lowering the outer wall speed, with minimal success.

I’m starting to run out of ideas. It seems like there’s some micro-oozing that’s collecting on the nozzle no matter what.

Has anyone else experienced this specifically with PLA Matte in vase mode?
Any help or suggestions would be greatly appreciated!

IMG20250609185744

Thanks!!!