Prusa MK3 is clicking and then under extruding  

Re: Prusa MK3 is clicking and then under extruding

You've swapped all the hardware I'd suspect. A bit more information might help:

1. What firmware are you running? Recent updates addressed extrusion motor heating issues that could cause melting above the hotend.
2. What slicer and settings are you using? Do you get the same problem printing the Prusa gcode samples?
3. What filament are you using? Different materials require different settings.
4. You listed a lot of things, but have you tried simply dialing down speeds to 50% using the front panel knob during a print? Wait until it starts clicking, then dial it WAY back. It will slow down, which sucks, but if it prints OK, you've got a strong hint.
5. When you say the "pulleys are jumping", which exactly? Do you mean the extruder is skipping back, or are you seeing something on your X/Y axes?

It printed well at first, so you should be able to get back to where you were. Take a break, then give a few more things a go. Good luck with it.

Re: Prusa MK3 is clicking and then under extruding

Hey thanks for your answer.
I am using prusa PLA 1.75 mm and mostly the default settings of the slic3r (layer height 0.15; infill 15% triangular, no support etc. didn't change a thing about printing speed or temperature)
about the firmware i am not sure. I updated the firmware about 3 weeks ago. Is that still the newest?
And I also get the same problems with prusa gcode (I am printing the parts for the prusa Lack enclosure at the moment and having a lot of clicking issues with them).
For what reason ever I didn't have the problem printing PETG (also default settings for PETG).
I haven't tried slowing the print down, but when I do, what hint is it then? That my printer can't manage the "normal" speed? does that mean , I will always have to print slower than? Or is that a hint that something else has to be fixed?
with pulleys jumping I mean the extruder is skipping, you can clearly see that, it is a lot.

Re: Prusa MK3 is clicking and then under extruding

Oh and I also checked, whether the extruder motor runs too hot. It does sometimes run really hot, but doesn't seem to be connected to clicking (clicking occurs both at hot and cold extruder motor)

Re: Prusa MK3 is clicking and then under extruding

[...] I haven't tried slowing the print down, but when I do, what hint is it then? That my printer can't manage the "normal" speed? does that mean , I will always have to print slower than? Or is that a hint that something else has to be fixed?It could be both. You may find an issue with a partial blockage or extruder issue that can be fixed. You may simply have a combination of filament that doesn't work at max speed. The important thing is that this will demonstrate that it can work, so you just need to figure out what settings work.

If it does work, my recommended process is to set everything up in Slic3r exactly as you have it now, then go into Filament Settings->Advanced->Max volumetric speed and change it from the default to a lower value. This setting ensures that the combination of nozzle size, line width, layer height, speed and acceleration don't overwhelm the extruder's ability to process this particular filament. Some are thicker than others (e.g. PETG uses 8 versus PLA at 15) You could try easing it back, or go the other way and set it low and work upwards. Try test prints until you find a speed that prints reliably for that filament. Save the filament profile off for future use.

Re: Prusa MK3 is clicking and then under extruding

Nice thanks, I will try that! I just assumed, that the default settings with the prusa filament should work...

Re: Prusa MK3 is clicking and then under extruding

Ok, it clicked now and I tried going to 50%. Unfortunately it didn't help at all 🙁 what can I do now?

Re: Prusa MK3 is clicking and then under extruding

Does it happen with a fresh new filament? I got moisture in my pla after a few weeks of room temp (23c at 45% humidity) and I started to have clogs and clicking. Would be good to discard this case.

If you manually extrude filament, how does it flow? Straight line or goes to some side? This is an indication of partial clog if not straight line.

Since you went from Petg to pla, has this started to happen after you went back to pla?

Have you tried cold pulls to make sure things are clean?

Re: Prusa MK3 is clicking and then under extruding

Hey,
The filament I am using is freshly unpacked. I extra ordered new filament, to make sure it isn't wet or dirty.
If I load filament, there is most of the times no clicking. It is extruded first straight and then forms spirals .
I would say the nozzle can't be clogged, since I just replaced it 5 days ago and the clicking appeared already 2 days after that again.
After I went from PET to PLA it was fine for a few prints and then startet clicking again.
I tried cold pulls, but everything was clean.

Re: Prusa MK3 is clicking and then under extruding

You've replaced just about everything mechanical, so I don't think a clog is still possible. The only thing I don't see on your list is checking the extruder tension screws (left side at top). They should be nearly flush. If that doesn't work, I'm out of ideas. Definitely open a case with support.

Re: Prusa MK3 is clicking and then under extruding

Hey,
that's what I meant with "played around with the tension".... so I've already tried it... I am tired of paying a lot of money for replacement parts , but could it be the extruder motor itself? The gears actually look really fine to me, but if necessary I could still replace both and the motor, do you think that would make sense? On the other hand, I want prusa to pay for that since 736€ is too much money to be broken in 4 months of careful handling 😡
I've written to the support, but no answer so far

Re: Prusa MK3 is clicking and then under extruding

I know this is an old thread, but I was wondering if you ever resolved your problem? I'm asking because I had some problems with my printer and sent it back for inspection. It was working a little better the first couple of days when I got it back, but now it is exhibiting exactly the same behaviour as you've described - clicking, then under-extrusion which inevitably leads to failed prints. It never did that before, and I've tried everything I can think of to stop it. Seems like I got rid of one problem, only to be faced with another.

Re: Prusa MK3 is clicking and then under extruding

I have this problem too, I seem to resolved it by pulling the filament back out ever so slightly whilst the printer is going...not really much force, but enough to give some tension.
I’m not sure it’ll stay fixed, but I think it’s the drive cog slipping on the filament, what does get extruded is just melted through..?

Re: Prusa MK3 is clicking and then under extruding

Dears, I have the same problem too.

Do you use b7extruder upgrade like me?

The printer is quite new. Used sometimes to arrive prepared to the mmu 2.0 upgrade. I mounted the b7 extruder included into the mmu2.0 upgrade and this problem (click+under extrusion) appeared.I rried unclogging, but the extruder was already clean. I Used new prusa filament+10 different brands.. no way. It seems that there is not enough force to push the filament inside. Only at +30degrees temperature the click seems ot disappear, and the flow seems to be bigger, but it is not the correct temperature to work with.. did someone solve the problem?

Re: Prusa MK3 is clicking and then under extruding

Hi all,

I am having the exact same problem. Prusa i3 MK2S about 4-5 months old. Worked like a dream until recently when the filament started catching, producing a clicking noise, and under extrusion occurring, which ruins the prints.

I resolved the problem initially by loosening the two bolts in the side of the filament idler. It seems that what is happening is the filament is being crushed by the gear connected to the motor, then when it retracts slightly, it cannot regrip the filament so it slips, producing the clicking. When unloading the filament, I can always see a few inches of grooves, caused by the gear, at the end of the filament which I have to snip off or it doesn't load the next time around.

This worked fine for a couple of weeks then without rhyme nor reason, on Thursday night last week it started happening again, resulting in multiple failed prints.

I tried adjusting the bolts again but this hasn't worked. If you loosen the bolts too much, it fails to grip the filament altogether (obviously). I have tried numerous PLA filaments PLA - rigid.ink, generic PLA, the filament shipped with printer etc, all produce the same. I have cleared the nozzle, repeatedly. I have removed the gear from the feeder motor and made sure it is not clogged (some bits of filament where it had caught and scraped it were apparent). I have tried replacing the bearing opposite the feeder motor gear with some custom designed cogs and wheels, printed in PET, which I was hoping would give more purchase than the perfectly smooth bearing, which for me, is the likeliest cause of these issues. It's either that or the poor tension mechanism between feeder motor gear and opposing bearing.

I'm about to try changing both gear and bearing for different types but not holding out much hope. Does the MMU have the same sort of filament feeder mechanism, or is it different (*better). I have it on order, but apparently won't ship til December.

Any thoughts or suggestions would be most welcome.

Many thanks,

Jim 👿

Re: Prusa MK3 is clicking and then under extruding

Dears, I`m back.

After a desperate cold pull, the problem disappeared. Probably the nozzle was really clogged.. we'll see.

Re: Prusa MK3 is clicking and then under extruding

Hi Matteo,

Thank you for your last reply, I hadn't realised the nozzle might be clogged so I tried a cold pull x2 and this seems to have worked for me as well!

Whenever I load new filament I am always careful to extrude a fair amount so that the flow looks OK. It must have clogged on me good and proper the other night but now seems to be working again!

I'd recommend this as a first step for anyone experiencing the same issue.

Cheers

Jim

RE: Prusa MK3 is clicking and then under extruding

Hi,

I'm also experiencing this extruder clicking, resulting in failed prints. 

What I have tried so far:

- printing the Prusa PLA I'm using at higher temperatures (up to 230°C).

- printing really slow

- played around with the tensioning screws

- took apart the extruder and cleaned the nozzle, pfte tube, bondtech gears (and checked shaft allignment). There were no cloggs.

Before every print I do a 'load filament' cycle to ensure good flow from the nozzle.

But nothing seems to work. Basically for the moment I can't print anything.

Any ideas?

RE: Prusa MK3 is clicking and then under extruding

@Jan -- Did you check the idler gear axle shaft?

Also, when it jams again and is clicking, stop the print and do a normal filament UNLOAD. Snap a photo of the filament end and post here.

RE: Prusa MK3 is clicking and then under extruding

I checked the axle shaft on the bondtech gear, it was pushed in right in the middle.

I will do an unload and post a picture.