Weird Underextrusion - eviltoast

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?

https://imgur.com/a/ggaZDMY

  • al177@lemmy.sdf.org
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    7 months ago

    What are your bed temps for PLA and ASA? Does it still happen if you preheat the bed? If you rotate the print, does the rough spot follow the rotation?

    • William@lemmy.worldOP
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      7 months ago

      ASA 105

      PLA 60

      I’ve tried with multiple different objects and all of them occur in the same place. If I turn a square 45 degrees, it’s now on a corner instead.

      • al177@lemmy.sdf.org
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        7 months ago

        I think your bed is warping slightly as it heats up, which is normal. Set your bed temp to 105 for half an hour before starting your print and see if it still happens. If you have a V0 or other manually levelled printer, get the bed to 105 before levelling.