#Unreliable extrusion inspite of extensive maintenace

22 messages · Page 1 of 1 (latest)

sly abyss
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I have a printer making slightly uneven extrusion and printing holes with gaping holes and ridges. I now have:
trimmed the burnt PTFE end and sanded it smooth, confirmed the extruder is good, switched and completely cleaned the nozzle, calibrated Initial layer height and esteps, beefed up the mounting strength, checked for clogs in the heatsink and made sure the heartbreak is property screwed in and am using filament fresh out of the bag of wich I already went through a dozen rolls and confirmed it to be dry using another printer.
All of this, twice

Yet my extrusion still seems blobby and uneven, even more so since I handled the PTFE tube.
The consistent gaps in the top picture are intentional, and there's been no changes to settings or hardware between the first and second picture

unknown.png unknown.png
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this is more or less the same support before and after

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at this point I have taken apart literally any component that I could, and cant chock it up to anything but evil spirits 😅
As it stands ill be forced to probably buy another printer so I dont have to refund my customers

violet wren
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it could be z steps possibly since those layers look pretty large

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and that would also give the effect of underextrusion

sly abyss
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That part is intentional.
My support is .64 layers at 70% flow

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I would show regular parts, but it doesn't even manage to do those without breaking it off a after a few layers due to the holes and voids

fleet swan
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is this a new printer?did it print properly before?

violet wren
sly abyss
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hundrets of hours of working fine, and then this developed over a 20-30 hour span

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and my nozzle is 0.4
Yes, I am aware it gets less accurate after .32 , but its not an issue for supports

violet wren
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those holes and voids are most likely caused by the high layer height

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a 0.4 nozzle can't extrude enough for a 0.67 layer height

sly abyss
fleet swan
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well, I can only guess that it may be:

  • degradation of PSU
  • temp sensor is getting faulty, so real temp is lower, thus underextrusion
  • something is off with extruder or it's motor
    I guess extruder is the first thing to check - maybe something is damaged or worn out.
    also, I'd recommend to replug all connectors just in case, to be sure they are okay and tight.
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and for diagnostic purposes you can try to print plain cube in vase mode at 20 mm/s, result should rule out some possibilities

sly abyss
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-no way to check that
-I'd guess that'd also make esteps be off, no?
-I mentioned I already ruled the extruder out. In fact I went far enough to buy a official replacement to test with instead

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I'll do the vase thing tomorrow. I replaced some more visually undamaged parts with spares I had aside for later projects (cause why the fuck not at this point)

fleet swan
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it depends on extrusion speed during calibration (which is usually low). so it's possible to get a situation where only some parts are underextruded because they are printed faster, or only some shapes for the same reason.

sly abyss
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I do 50mm/s during calibration and get about 5% underextrusion for every doubling last I tried (tested up to 400)

sly abyss
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Okay, I switched the hotend assembly for a spare I had and flipped the PTFE tube while keeping the electronics.
It's still a bit oozy and but it looks close to what it should be again

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Any idea what could be wrong with the other one?