About a week into ownership of this H2D printer. Was printing PETG very well. Tried Prusa PC Blend Black and had layer separation. Tried PolyMax PC and it printed perfect. Next I tried Bambu PC Black, at first it printed, then “Extruder Overload”. In the past as long as I could see the filament being extruded, I would cick “Issue resolved” and the print would continue. But with the PC filament here was no extrusion. Removed both nozzles, heated with a FX-888D soldering iron. Left nozzle was clogged solid with the PolyMax White PC, was able to clear the nozzle well. Right nozzle was clogged like heat soak, with melted filament all the way to the top, I was able to clear this nozzle also, but noted that the 0.4 tip appears to be undersized. A 0.38 cleaning rod is always tight.
I will try again with the chamber temperature turned down from 60 to 40.
PolyMax PC is modified for easier printing with lower stress, while Bambu PC and Prusa PC Blend are standard polycarbonate formulations that require higher flow and chamber control. The “Extruder Overload” occurs because the filament becomes too viscous at your chosen settings, especially with an undersized nozzle tip (0.38 mm will raise pressure significantly). Lowering chamber temperature may reduce heat creep, but the correct fix is to replace the nozzle and ensure proper extrusion temperature and drying of PC.
I only had one clog and did a cold pull on the high flow nozzle using a candle to heat it. Pulled out everything and strangely it did not look like a cold pull that came out of a high flow nozzle. I thought these high flow nozzles had a chamber that split into 2 or 3 tunnels and then went to one. The cold pull looked more like it just went into a single slightly bigger chamber then down into the nozzle tip.
