On the bottom of my prints, there’s an area of underextrusion and I can’t figure out what’s causing it.
I first noticed it when I switched back to a textured PEI bed while trying to print ASA. It’s on 20x20mm squares, and it’s on the test print for setting up pressure advance… But only on the left-most object.
It’s the same even if I add 2 lines of skirt or not. (In addition to my KAMP Voron purge.)
It happens everywhere on the bed that I’ve tested. It happens to PLA, but it harder to see. For ASA, it’s very obvious. For PLA, it’s almost as smooth as the rest of the surface, but it’s there if you know what you’re looking for.
I’ve only been printing PLA for quite a while now, so I don’t know when this started.
I’ve got an LDO Voron 2.4 with Tap, KAMP, Revo hot end. I’ve calibrated pressure advanced and changed the value, and I’ve tried different z offsets with the textured bed, which doesn’t change it. (But does change how good the rest of the bottom surface looks.)
Anyone got any ideas?
I completely understand that. I’m fighting my own battles with getting a consistently perfect first layer. I’ve been fiddling away for a while now and for whatever reason my last print had extrusion stop about 2/3 way through. Heated the nozzle up this morning, told klipper to extrude, and it extruder perfectly happily. No console errors from the print and klipper thinks it completed successfully.
When I’ve had something like that (or just underextrusion randomly part way through a print) I’ve decided it was a clog and did a “cold pull” on the filament to fix it and it seemed to work. It can be insidious because it sometimes clog and sometimes doesn’t.
Though, I’ve also had people suggest it was “heat creep” where the heat gets too far upwards and melts the filament too early.
I’m planning on swapping nozzles soon, might as well do a pull or three just to be sure. I wonder how that will work on my Rapido though… it seems to melt all the filament in it and it all just oozes out by the time it gets cold. 9 times out of 10 I can flip the latch on the CW2 open and just pull the filament out of the reverse boden cold.
Whatever happened happened, I’m much more bothered by my inability to get a consistent first layer. Each new thing I try also sets me back some while I tune. The joys of tinkering with your printer and wanting to get it just so. It’s already miles better than my old i3 clone ever was but the possibility of near perfection is too enticing.
What are you using for a probe? I’ve guessing the first layer problem is something subtle to do with your probe. If it’s a Tap, it’s probably filament on the nozzle and you’ll need to clean it before each print.
Klickey, but I still make sure to give the nozzle a wipe before homing z on my end stop. I think I realized what my most recent goof was: I (finally) enabled bed mesh, but was using a different ze opoint than my calibrate_z macro. Calibrate_z was more consistent than just my z end stop, but it was ever so slightly out of plane. I will be making another attempt today to see if that was it.