3

I was running my Ender 3 just fine with good first-layer adhesion/everything else but my setup changed after my Pi SD card got corrupted so I had to re-install and reconfigure my bed leveling via OctoPrint. After this my first layer started to look like this:

Image of 3D print first layer * this is the bottom of the completed print

IIRC I changed the following (and have tried undoing it but to no avail):

  • Increased extruder tension (since it was skipping while retracting)
  • Lowered z-probe offset (since re-calibrating it was too high)

This is with PLA

Running a modified Ender3 w/

  • BL Touch
  • Micro Swiss Direct Drive Extruder for Creality CR-10 / Ender 3 Printers
  • PEI Plate
  • BIGTREETECH SKR Mini E3 V1.2 Control Board w/ Marlin dev built 20210609

Sliced on Cura 4.11.0

  • Printing Temp: 210.0 °C
  • Bed Temp: 60 °C
  • First Layer printing speed: 20.0 mm/s
  • First layer acceleration: 500.0 mm/s^2
  • No first-layer fan (or any cooling at any point)

I've tried:

  • Increasing initial Z-offset; this doesn't work since it will affect my bed adhesion to the point the print will pop off
  • Adjusting extrusion gear tension; will start skipping on retraction/no-luck

After the first couple of imperfect layers get ironed over, the upper layers will not have any extrusion problems, or whatever this is, and are basically fine.

agarza
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Cody Duong
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    This has been asked before, but I can't find the question. I think the nozzle is too close to the bed. Will try to find it! – 0scar Oct 19 '22 at 23:02
  • Yeah this is it, it's strange because I'd never seen an extrusion pattern like this. Anyways after opting for higher rather than lower and swapping to a glass bed so it would be flatter I was more easily able to get this tuned in. If you want to write/link to the other answer as an answer I would be willing to accept it as correct. Thanks. – Cody Duong Oct 20 '22 at 02:46
  • I can't find the other question, but know it exists. Please write your own answer and accept it after 48 hours. We can always mark it later as a duplicate when i have found the question. It is good to have duplicates because this issue is hard to capture in a question title and key words. – 0scar Oct 20 '22 at 21:24

1 Answers1

3

Solved, the nozzle was set too low and was causing pressure buildup at certain points since the PEI plate wasn't perfectly flat.

After raising it and swapping for a glass bed I was able to stop this behavior.

Note: While this helped this issue a little bit, it was also making adhesion really poor on faster prints. A better fix I found was that I recently swapped filament spools, it looks like the average spool thickness was greater than the previous one, and after reducing the flow 5 %. I was able to eliminate this problem entirely, thanks to the question What is causing 'droplets' on first layer?

agarza
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Cody Duong
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