Core 1: severe underextrusion?
Moin!
Over the last days I upgraded my MK4S to a Core 1 and added the camera, filtration and MMU3.
The printer produced one normal looking nice first layer, than it stopped extruding correctly. During printing there are clanging noises which - I believe- come from the extruder.
No failure messages at all, all calibrations passed, MMU3 seems to do its thing.
What should I do next? I pushed the hotend up as far as I could, I did several recalibrations of the extruder gears, I tightened the extruder idler screws a little bit...
This is the wrecked beginning of a benchy:
Beginning of print:
RE: Core 1: severe underextrusion?
It's possible the idler tension screws are too loose. Try tightening both 1/8 of turn each. Sounds like the filament is slipping on the extruder gear.
RE: Core 1: severe underextrusion?
yeah, the standard setup for the extruder screws used for the mk4 series still apply! I recommend checking the full build instructions and check if you can spot any major differences in the way the extruder is setup...
RE: Core 1: severe underextrusion?
Hey!
Thanks for bothering. I tried and tightened the idler tension screws in 2 steps. I tried to print 2 benchies but have the feeling that extrusion now is even LESS. My scres now protrude for about 2mm out of that "nut". Would it be OK to tension them even more? All online resources ever say to just get them even with the rim of that nut.
My current idler screw position:
Base of benchy after tightening idler screws:
Nozzle cleaning still not looking healthy:
RE: Core 1: severe underextrusion?
Hey!
Thanks for bothering. I tried and tightened the idler tension screws in 2 steps. I tried to print 2 benchies but have the feeling that extrusion now is even LESS. My scres now protrude for about 2mm out of that "nut". Would it be OK to tension them even more? All online resources ever say to just get them even with the rim of that nut.
That's now too much, loosen them so the screws are flush with the nut. Next, try running the gearbox calibration. Also check the nozzle for clogging.
RE: Core 1: severe underextrusion?
Hi!
I do not know how to continue further. At first I thought I had found the culprit. Disassembling the gearbox showed debris and the broken O-Ring from that new base plate:
I cleaned everything up, installed the spare O-Ring and painstakingly reassembled, did the gearbox calibration and tried for a benchy. No extrusion at all. A lot of clanking:
I opened the gearbox again and found the O-Ring to be OK this time, but again: Some debris in that gearbox:
I never printed black on that printer, yellow is what I am using for my first tries.
What should I do next?
RE:
What should I do next?
Only other thing I can think of is the idler tension pulleys are misaligned or they are not rotating freely and the filament is not getting fed into the heat break tube of the nozzle assembly. Also, have you tried a different filament?
I think next you should contact Prusa support over chat. They will be best qualified to help you at this point.
RE: Core 1: severe underextrusion?
... or the channel in the gear where the filament is supposed to be running is not aligned properly with the extruder... but here is @hyiger right, at this point you better engage the right support!
What should I do next?
Only other thing I can think of is the idler tension pulleys are misaligned or they are not rotating freely and the filament is not getting fed into the heat break tube of the nozzle assembly. Also, have you tried a different filament?
I think next you should contact Prusa support over chat. They will be best qualified to help you at this point.
RE: Core 1: severe underextrusion?
All is well!
Thanks for your help. What seems to have happened is this: During the very first print -which started fine- the O-ring in the gearbox broke. Parts of that O-Ring found their way into the nozzle and that was totally blocked. I swapped the nozzle and voila!
Thanks again and be careful with that O-Ring!
RE: Core 1: severe underextrusion?
good to read you are now happily printing 😀