Extruder clicking noise and under extrusion
Hello fellow XL users.
I have stumbled onto a problem that requires my printer to be sent to Prusa for repairs. Well the printer is usable when avoiding large prints, but whats the point of having an XL if can't print prints that require entire bed size, am i right?
And you well know that sending the printer requires shipping + labor and probably some parts which equals to €€€...
Don't get me wrong the Prusa support is great and I really appreciate how fast they are with responses.
Printer has part changes through warranty:
- Extruder cables;
- Extruder motor;
- Dwarf board.
Now to the problem.
Printer setup: 0.6 HF Nozzle, Prusament PLA and no enclosure as this had to be removed to continue with Prusa support.
When printing big flat objects 0,32-0,4mm layer height the extruder starts clicking (usually 2-3 layer) although the filament is not stuck or anything and with the clicking the print surface has a gap - no filament extruded for a brief period of time.
What I observed so far:
- When i manually push filament to kinda help the extruder, the clicking and under extrusion stops.
- When the print speed is lowered to ~80%, clicking and under extrusion stops.
Here is everything that i have gathered so far:
https://drive.google.com/drive/folders/1qW6Y_0LDzTs7AO3OR61YswmH40xYvoMv?usp=drive_link
I think that the latest date videos describe the best overall situation:
https://drive.google.com/drive/folders/1D6mBfjW-ztWJZDgRpaaqzlWwRUpnmYgL?usp=sharing
So just maybe someone has some theories what could be happening?
Maybe if you have some time to check if printing with same settings and setup causes your printer to act the same way?
3mf:
https://drive.google.com/file/d/17fmRaesVcpX59vW1jqaWvfO_oB0Vg206/view?usp=drive_link
Any feedback is appreciated and i need to have some other opinions or even maybe find a solution before sending the printer to Prusa.
So the problem appears about when the faster infill starts...
Temporarily disconnect a PTFE tube and try pulling the filament through by hand - is there a lot of resistance?
If you can, bypass the tube and feed filament from an overhead tube direct to the head - does it print OK?
If yes to either of these:
You may have dust in the tube or the inside of the tube may be worn causing resistance - clean it out or replace.
Your extruder idler pressure may be wrong, perhaps due to filament with out of spec diameter...
measure the filament in a few places and average, if off enter the value in the slicer, try adjusting the idler pressure (might be either way); keep count of the turns to make it easier to go back.
Cheerio,
RE: Extruder clicking noise and under extrusion
Hi.
Thank you for the tip!
I was sure that the tube nor the filament sensor arn't causing any friction as the filament went through really smoothly, but further testing proved the opposite.
To my understanding the clicking noise is extruder skipping steps due to torque/force limitations of the stepper motor.
Testing observations:
- Tool2 does not have an under extrusion and clicking issue when running filament through filament sensor.
- Tool2 is starting to have under extrusion and clicking when increasing speed by 20%. It is not as severe as Tool1.
- Tool1 does not have an under extrusion and clicking issue when running filament directly to extruder.
- Tool1 under extrusion and clicking appears when increasing the print speed - speed increase was done just for testing purposes.
- Tool1 does not have an under extrusion and clicking issue when running filament through new filament tube without a filament sensor.
- Tool1 under extrusion and clicking appears when increasing the print speed - speed increase was done just for testing purposes.
- Tool1 under extrusion and clicking returns when feeding again through filament sensor with new tubing.
Conclusion:
The filament sensor is causing friction that causes filament to be under extruded, but this does not explain the motor skipping (clicking noise).Is the Tool1 extruder motor skipping because of limited motor capabilities ? Faulty extruder motor ? As soon as little obstruction is in the way the motor starts skipping.When increasing speed the extruder tries to push too much material and the motor is not managing it and the nozzle does not allow to pass that much filament?
If necessary please see the videos that i uploaded, I have named them for better observation:
https://drive.google.com/drive/folders/1U1LKUkCOEjTEYwLXyRtZV22E5KwoxldX?usp=sharing
Waiting for second opinions.
It isn't the sensor.
You rarely feel much resistance when pushing filament into the extruder as the pressure lifts the filament away from the gripping surface(s).
When the filament is pulled by the extruder motor - or your fingers when the tube is disconnected - the filament is pulled against the gripping surfaces/debris. If the tension is enough and the extruder idler is tight the motor may audibly skip steps, if the idler is loose the drive gear may loose grip or grind the surface from the filament, audible again.
Some filaments are dusty, some printers are in dusty workshops; dust drawn into the tubes can build up and cause jamming.
Some filaments, often ones with included particles, are abrasive and wear away the smooth internal surface leaving a rough, grippy, contact area where the tubes bend. Some colours of apparently innocent filaments (white, pastel, glow-in-the-dark) may be semi-abrasive without you realising it.
To aid diagnosis, try swapping the tubes from a freely working toolhead with the suspect toolhead and see if the problem follows the tubes.
Sometimes cleaning out the tubes with compressed air is enough. Sometime rotating the tubes 180 around their axis moves wear out of the way. Otherwise replacing the tube(s) may be the answer.
Cheerio,
PS: Please post videos here rather than external sites.
RE:
Hi.
I already did the test you recommended. But i just used a new tube, I didn't swap.
I think that the testing observations explains clearly that the friction is causing motor to work more and in one point the motor fails with pulling resulting skipping.
Short desctiption:
Feeding directly - no issues with the troubling Tool1
Feeding through new tube - no issues with the troubling Tool1
Feeding through sensor and new tube - issues start to happen again with Tool1.
Some of the videos are large enough that cannot be uploaded.
Videos that i was able to upload,
Which prusament filament are you using?
Does it work with other filaments?
Another test worth trying: swap the troublesome toolhead with a good one (you will need to run through tool offset calibration), does the problem follow the head?
Cheerio,
RE: Extruder clicking noise and under extrusion
I've used Galaxy black PLA and Jet Black PLA.
Not tested with other filaments.
Todays procedures:
- Cleaned side filament sensors - probably not related, did it just incase.
- Swapped the tools.
- Tool offset calibration.
- Filament sensor calibrations.
- Ran the test print with both tools:
- Tool2 (previously tool1, troubling) - no under extrusions
- Tool1 (previously tool2, OK tool) - under extrusions/clicking started from 3rd layer, usually it started from second layer and then it was more severe.
PS! Increasing speed by 10% started the under extrusion on the Tool2 (previously tool1, troubling) - just for testing purposes.
Sorry for my language, but wt* does this mean ?
So it's not the E-motor, should i change the tool cable (splitter-dwarf) ?
So that isolates the problem to one particular head.
Revisit the gear cleaning procedure:
https://help.prusa3d.com/article/regular-printer-maintenance-xl_401237 - scroll down to 'Nextruder'
And recheck the idler pressure.
Cheerio.
RE: Extruder clicking noise and under extrusion
Sorry, maybe my explanatuon was too complicated.
The problem stayed on position 1.
Promblematic tool1 on position2 worked good.
And the OK tool2 started to have issue on position1.
Problem is in the first position. But how and what?
Oops, OK, in that case we've isolated the problem to the tool position/dock.
Try swapping the PTFE tubes and see if the error follows the tube. Blow through the sensor and the tubes with compressed air while you have things disconnected. Make sure the tubes don't have unnecessarily tight bends.
Everything points to a physical cause - and to some cause of excess tension in the filament path in particular.
Cheerio,
RE: Extruder clicking noise and under extrusion
The PTFE tube was changed.
Filament sensor taken apart and cleaned.
I'm not sure how to proceed any further.
😣
OK, let's go back to pulling filament manually.
Disconnect the extruder end of the tube and feel the pull tension.
Try with a different filament - is the pull easier?
Try from a different spool holder
Hold the tube in a different position to reduce tight curves
Move the far end of the tube to a different sensor
Cut off a length of filament longer than the tube and slowly pull it all the way through - is there a point where it suddenly becomes easier - where was the end?
Try as many variables as you can until you lighten the tension.
Cheerio,