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

  • WilliamOP
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    17 months ago

    I tried a never-used nozzle with no difference.

    The bed hasn’t been cleaned in a while, but the parts that aren’t underextruded stick very hard. And it happens the same in every place on the bed (I’ve tried about 8 now, always with the same pattern) and 2 different beds.

    I’m still thinking it’s a pressure issue, where it initially doesn’t have enough pressure for some reason. But I turned up the KAMP purge flow and it made no difference, and extruding 2 skirt lines made no difference that I could tell.

    My next step is going to give the bed a good cleaning… And even try the other side that I’m pretty sure I’ve never used yet.