Under-Extruding
Hi I have been getting pretty good prints with PETG for a while, but after my filament got tangled and messed up a print my extruder has been under-extruding. So I get these swiss cheese prints. where the shape is roughly right but there is far too little filament. I have two Prusas, so I took the SD card from one and printed in the other with the same filament and got great results - so it is not the file. here is an example of the bad print.
Here is a list of the things I have tried:
+ Checked the knobbed gear attached to the stepper to make sure it was tight.
+ checked the extruder idler
+ checked print settings with multiple prints
+ I dont believe it is clogged - I have run a bunch of filament through the extruder and it seems to be fine.
+ I cleaned the hobbed gear and there didn't seem to be any residue.
I am flummoxed... Any tips would really help. In the past with my Taz, under-extrusion almost always had to do with the idler... but I am new to the prusa.
Re: Under-Extruding
I am having the same issue. Petg got tangled mid print while I was asleep and since then I've had extruder issues. At 1st the extruder would just stop mid print. The only way to make it go again was a printer restart.
Now I'm also having under extrusion issues.
I guess the only thing to try is replacing the extruder stepper motor. Which is unfortunate ly out of stock atm
Re: Under-Extruding
Don't just throw parts at it. Does the extruder motor operate? When you load filament, does it extrude any? I know more experienced users will give you more things to check, but I doubt there's a need to replace parts. That seems to be a proposed solution a lot of people have for a lot of issues, but it rarely resolves the issue.
Re: Under-Extruding
There's about ten other things I'd try before even thinking about replacing the stepper motor. Stepper motors really just don't fail that often, so if your stepper motor ever worked, the odds are that whatever problem you're having isn't the stepper motor. Even if the stepper motor doesn't function, chances are that you need to replace the motherboard not the motor itself.
In your case, assuming that you're using the same print settings as before, underextrusion like this is probably a partial nozzle clog. Nozzle clogs are common. Stepper failures are extremely rare.
There's a whole section in the Prusa manual about how to clear a nozzle clog, but here's what I'd do:
If you've tried all three of those things and you're still getting underextrusion, then you know for sure it's not a clogged nozzle. I'd still check the motherboard before replacing the stepper, though.
Re: Under-Extruding
I cant be sure that it was the extruder or just the disassembly and reassembly process but i replaced it and its now working as normal.
Im sure it was not a nozzle clog, I had already replaced the nozzle.
Re: Under-Extruding
Partial clogs, IMO, can be tricky sometimes. You could extrude a whole roll of filament and not have a problem UNTIL you began printing something. I firmly believe that you can get a "floater" in the hot end that doesn't cause problems UNTIL you get a little back pressure when actually printing. I'm probably wrong but that is what my experience has been.
Neal