Patchy extrusion and PLA
heya, i've had the mini for almost 2 years now (its totally stock and did this from day 15) and very early on i pretty much abandoned PLA due to the clogs and patchy printing that just didnt show up on PETG. I've always had to run the printer filament a lot hotter than the defaults (230 vs 215 on pla and 240 vs 230 on petg - increasing even these as the spool ages) and often had to drop the speeds and increase the temps to avoid clogs and extruder filament chewing.
I mostly resolved this on petg - it seemed a lot more forgiving and didnt clog, the quality was always really decent, however PLA was a different story.
I had an roll of PLA to use and dreaded trying to get it working - its literally a year since i last printed pla - but upon installing it and doing a purge at above stock (230ish) it was still extruder clicking etc and i saw - what i can only describe as - regular under extrusion based on material quantity printed.
By this i mean ar regular intervals on a print the amount of filament extruded was less, leaving areas looking patchy.
Initially i put this down to the bed levelling and z as its most apparent on the flat bed surface, however it happens all through the layers and is tied to the amount of filament throughput - not the location on the bed. eg if the print has long lines to print out the patch is long and thin, if the print has small blocks of repeated lines the patch will be short and wide - which makes me think its a volume of filament it needs to get through before returning to normal.
Does anyone have any insight as to why the extrusion seems to be flowing like this?
It does happen on petg too, but no where near as much.
In side news, correcting the extruder clicking and clog avoidance by temp increases i've discovered somewhat bizarrely that printing pla way way up at 265 means i can print at 250% speed too... I always slowed it down and mildly upped it to correct it.