P1s print quality decrease after disassembling extruder

Bambu Lab P Series Troubleshooting
1

I was getting clogs in my extruder from the filament bulging by the extruder gear and being unable to move. So I had to take the extruder apart several times. I know about heat creep now and keep the lid and door open. I haven’t had any more clogs, but my p1s started printing like this and I haven’t been able to figure out why.

first layer
first layer1562×2074 723 KB

first layer2
first layer21920×1446 368 KB

  1. I’ve tried 3 different hot ends to rule out partial clogs
  2. I disassembled the extruder to make sure it’s working and filament passes though easily.
  3. I switched out the extruder gear and made sure it doesn’t have any residue/filament on the teeth that pull the filament, none of the other gear teeth are worn down
  4. factory reset → calibrate → bed level
  5. manual tension the x/y belts and cleaned the rods → calibrate → level
  6. tried different z offsets in the machine start code
  7. removed AMS and been using external spool directly feed into print head, no tubes
  8. tried different filaments
  9. increased bed/nozzle temps (helped a little)
  10. increased flow ratio (helped a little)

I’m using a 0.6 nozzle, Inland PLA filament, and the gold textured PEI plate

p1s-machine-filament-settings
p1s-machine-filament-settings1282×898 99.1 KB

p1s-filament-k

Increasing bed temp helped with adhesion problems I was having, I think from opening lid/door. Increasing nozzle/temp and flow ratio helped reduce the gaps between the lines in the squares of the first print. In a lot of these first layer tests prints the bo9ttom right corner looks good, then it starts breaking up.

Anyone know what could cause those gaps between the lines? This machine was printing perfect first layers last week. I’m not sure what else I can do.

2

Looks to me like you may have a dirty plate–weak adhesion. If you print a lot of filaments, you may want to wash the plate every other day. Run your finger across the inside of the door glass. If you get a smear, that’s what’s on the plate too. Clean the door glass as well as the plate. I use the glass as an indicator.

3

Cleaning the plate was the first thing I tried. I scrubbed it down in the kitchen sink with soap and a clean washcloth. My problem seems to be inconsistent under extrusion rather than adhesion issues.

4

There’s your problem. Use a scrub brush. I’m guessing the washcloth is probably contaminated with fabric softener/drier sheet wax. The soap must also be plain dish soap without any added conditioners. Don’t use any that are “creamy”.

5

Thank you Ken. I’ll definitely start using a brush instead.

6

I’m back to perfect prints again! I think I had two different problems. The first was that I wasn’t cleaning the plate properly. The second issue was that I didn’t assemble the extruder correctly. I took it apart to check it and noticed the yellow gear had a weird wobble. Then I noticed one of the bearings was missing! When I replaced the extruder one of the bearings stayed attached to the shaft of the old extruder. I hope showing this dumb mistake helps someone.

extruder
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