Hello,
i am currently using a 250h old Bambu Labs A1 Mini with a .4 hardened steel nozzle. Since the beginning I have got some problems with BL PLA Basic in black color. On all my prints are some weird looking holes, as if the filament would be wet. It’s really extreme when I print with standard BL settings for PLA Basic, these holes are just everywhere! When reducing the temperature to the lower end of 190°C, the holes disappear to 80% and are less noticeable, but they are still there. But printing at that temperature is a bad compromise to me, because of the weaker mechanical properties.
The filament got dried multiple times at 55°C for 8h or more in a Creality Space Pi with a small lid opener to let moisture escape. I also tried to change retraction length settings because I thought it might be air that gets sucked into the nozzle, but prints stayed the same after reducing the retraction length to .2mm in .2mm steps from the standard .8mm setting.
I heard some saying that if reducing retract length helps, it might be a worn out nozzle, but in my case I think its not. I have another .6mm hardend steel nozzle and the standard 04mm steel nozzle that came with the printer. All of them show same results, although they are pretty new.
I also opened up the print head and cleaned the extruder gears as shown in bambu wiki, prints stayed the same as well.
I am curious to hear any ideas to solve my problem, thanks!
printed at 190°C
benchy printed at 220°C