Heavy printer problems because of under extrusion
Hi all,
I need help because of printer issues that lasts now for a longer time. Since about the middle of february I cant print things confident satisfactory anymore. Since this time I try to find a solution and have tested several hints out of other posts and several instructions and calibrations, everything without success. To my problem:
I think the root cause is an under extrusion. If I'm wrong I can be corrected, with pleasure.
All began with a horrible infill structure. In normal case I use the default settings of prusa, which worked fine since the beginning of my printing career, but now it looks like this:
In default I use the Infill "Grid" but suddenly the crossing lines were hidden by the nozzle and the infill was teared. First I thought this was the problem, but now I think especially the infill is under extruded because of the higher print speed and because of this several lines are lost and so the structure itselve is damaged and can protrude, what hits the nozzle which increase the damage.
Now there are some more problems, which all leads to the theory of under extrusion: Prints are aborted in the middle of the print (left picture) but filament is still coming out (very much too little several times, so that the contact can be lose), or even prints are printed horrible after the first lines (middle picture), or at least, when the print seems to be good at the end the infill protrudes and leads to an horrible surface (right picture)
So you see, I seem to have several problems but I think it is all the same: Under extrusion. Please can someone help me, how can I fix this?
I am confused because the first half year since I have the printer, it was all very fine. I could print wonderfull objects, but suddenly this.
I have tried several things, all without success (not even with a tendency to improve):
- Different temperatures
- Different print speed (picture below: From left to right default settings of PETG with 100% / 80% / 50% Overall print speed adjusted on the printer itself)
- Different infill print speed
- I have lubricated all axes
- I have cold pulled the extruder, there was not realy much dirt
- I printed without the MMU2
- I have completely reassembled the hot end
- I have completely reassembled the extruder (due the MK3S/MMU2S upgrade)
- Different infill structures from grid, to honeycomb and Gyroid
- I am sure I cant remember all the things I have done, further more.
To my printer:
I have the MK3 (since august) with the MMU2 since december. About 2 weeks ago I assembled the MK3S / MMU2S upgrade.
Has someone already seen such print results or experiance about this in any other way?
Has someone a good tip for me which I perhaps havent tried, yet?
If you need more informations for a better help, I will try to give them.
With best regards
Edit: Further informations to the pictures:
- The silver objects are printed with Prusa Silver PLA FLM-PLA-175-SLV
- The orange prints are printed with Prusa Orange PETG FLM-PET-175-POR
- The white prints are printed with PETG of another manufacturer
RE: Heavy printer problems because of under extrusion
I have to write a new post because i cant edit my first one any more. But i want to give you some more information that might be helpfull to know:
- I use the actual firmware for MK3S: 3.7.1 - 2201
- I use the actual firmware for MMU2S: 1.0.5 - 297
- I use the actual non-beta Slicer Version: 1.41.3
Further things i remembered since the last post, which i already have checked:
- I took new thermally conductive paste onto the hotend like described in the wiki to mount the hotend.
- I checked the extruder screw which holds the gear
- The bondtec gears are already aligned
- I had printed the benchy with gCode sliced with the actual slicer version and with gCode of times ago, which gCode the printer already could print beautiful. No difference in print quality, it looked like the white PETG benchys shown above.
I still need help very much and would be very grateful for advice on how I can at least reduce the source of error further!
RE: Heavy printer problems because of under extrusion
did the printer ever print good?
if so maybe the nozzle is bad.
I have a Prusa,therefore I research.
RE: Heavy printer problems because of under extrusion
Check the e-steps. You'll need to mark your plastic precisely 100mm above the feeder, then use software to extrude 100mm. If the mark is still above the feeder you have under extrusion.
RE: Heavy printer problems because of under extrusion
Hi toaf, thanks for your answer!
Yes, the printer has printed in my opinion perfect prints. They were super dimensionally and structurally stable.
I have printed with PLA and PET, yet.
Oh yes, when the misserable print results started i had printed with several PLA filamentss, much more than the shown filaments. All this prints ended in the same results, like shown above. Amongst all these filaments there was Prusament (Galaxy), too.
The filaments i used were bought fresh and some PLA from amazon basic, PLA and PET from Prusa and as even mensioned, Prusament.
The nozzle is the hardened steel nozzle from prusa and is in usage since about the rebuilding due to the MMU2, also since about end of Dezember/Januar.
RE: Heavy printer problems because of under extrusion
@ graham-m5
Ok, i checked this just now: I marked the filament at the end of the PTFE-tube of the MMU2 and marked it again after the 100mm, 3 times. Every time it was used a filament line of about 98mm. When we think about inaccurancy this result is quite good, even surprising me because I see it at the printed objects that there must be something like under extrusion.
But it struck me, that the filament line looked a little bit other than the line which is printed when it prints objects, a little bit fuller, more the filament line i know from earlier prints. It also stands out that the first one or two layers of a printed object are quite good, so the issures come in the meantime of a print. I will soon try a new print of the round object as shown in the pictures. This one he was never be able to print correctly before (since the failure time).
RE: Heavy printer problems because of under extrusion
Okay, i have printed the round object, i think there is nothing more to say than to show the result till the manual print stop:
You see the first layer was printed well, except the contact points from the surface to the edge.
Directly the second layer is horrible, nearly not existing.
So it seems the nozzle is clogged, but even as i said, i made cold pulls, there was no dirt. When i start the next print it will look the same, even if i pay no attention to the "clog".
RE: Heavy printer problems because of under extrusion
that first layer is not close enough to the bed. there should be no gaps between lines at all, it should be as smooth as you can get it.
see this thread:
RE: Heavy printer problems because of under extrusion
After I removed the failed print from the bed I could see the lines of the first layer dont hold together as they should, too. So either there the first layer is wrong calibrated, or even in this line is too less filament.
The first layer I have calibrated yesterday last time, there the test field was printed very close and the lines could not be removed from each other:
So it seems to be too less filament, even the lines seems to be very thin? Can this still be a signal for under extrusion?
RE: Heavy printer problems because of under extrusion
Okay, the second test print is failed, now the situation is better to see: When the print started, the first layer was adhere very well, the lines are not to remove. Some time later, while the first layer is still printed, the structure gets lost, the lines are removeable as the print before (left picture).
Even the further layers were not print successfull. Now i could clearly see again, that the nozzle was clogged this way, that nearly no filament came through (right picture). Only some mm of filament get out of the nozzle every few seconds.
When i look into the hotend, what i even have done several times, there is no dirt.
I will remember again, i never have changed something in the software (except firmware updates and slicer versions) because with this settings it always worked before, very well.
I think it must something to with the hardware. But there I think i have checked everything. Is this issue and some solutions known about that?
RE: Heavy printer problems because of under extrusion
Good news! I have found my error in my building.
Long time before, I have remastered the filament holder which were part of the MMU2 upgrade, for guide my filament to the printer. The new filament holder worked still on the principle like the original ones and after I have seen that my remastery even could not make this better, i had the filament only let pass the L-Part of the folding mechanism. Because the printed part is PETG and not PTFE and the filament what was guided through it (PLA and PETG) had direct contact to this material, the friction seems to be such high, that the extruder needed too much power to get the filament continuously out of it.
Yes, I checked the e steps and they were OK, but the problem has not appeard every print! Slow prints I could print much better, sometimes even completely, so prints with much wall and quite a small amount of infill. Mainly when the printer was printing fast (infill) the issues appeard. Not this is explainable with the friction.
So, now I have reworked the filament management again, and it got much better. But there are still problems. Because I think the reasons for that are other things, I think this thread is solved. I will make new threads for the other issues.