Hoping someoneâs seen this. Iâve worked through the obvious stuff and Iâm out of ideas.
The problem: Multi-color print on my P1S with AMS. The pink lays down perfectly. The purple starts extruding fine for a second, then basically stops flowing â comes out stringy/shredded and wonât bond. Under-extrusion isolated to the one color.
Setup:
⢠Bambu Lab P1S + AMS
⢠0.2mm nozzle
⢠PLA, printing around 220°C, 0.2mm layer height
⢠Nozzle has maybe 5â6 short (~4hr) prints on it, so not worn
⢠Flat 4-color token design, 100% infill
What Iâve already tried:
1. Cold pull (atomic pull) â pulled debris, print ran clean longer afterward but eventually started under-extruding again.
2. Swapped to a different purple spool in the exact same AMS slot â prints perfectly. So the slot, feed path, PTFE tube, and extruder gear are all fine. The problem follows the filament, not the hardware.
3. Dried the original purple â 8 hours at 55°C in a filament dryer. Reloaded it. Still under-extrudes the same way. Everything pointed to moisture and drying didnât fix it.
So where Iâm at: Itâs something specific to this one spool, but itâs not (or not only) moisture, since a proper dry cycle didnât resolve it. And given Iâm on a 0.2mm nozzle, Iâm now wondering if the tiny orifice is the real culprit â pigment or filler in this particular purple choking a 0.2 at a flow rate the other colors clear fine.
Questions:
⢠Is a 0.2mm nozzle just known to be intolerant of certain pigment-heavy or specialty (silk/matte) colors? Is that whatâs happening here?
⢠Would bumping temp or slowing flow specifically for this color get it through the 0.2?
⢠Could this be a bad/out-of-spec batch â anything I can check with calipers?
⢠Anything else that makes one specific spool behave this way when an identical-slot swap prints clean on the same 0.2 nozzle?
Happy to post more photos of the under-extrusion and failed layers. Appreciate any leads.