Filament gets stuck repeatedly during printing  

RE: Filament gets stuck repeatedly during printing

• I am having this problem with my 4s too. But when I reload it stops after about 20 seconds. It rendered my machine useless. It's never completed a print. I think my sensor is no good cause it only registers a filament in there if I jam it in with pliers and even then it only works about 1 time out of 20. Many broken bits of filament and a very expensive machine that I bought because it's supposed to never fail. And it's never succeeded 

RE: Filament gets stuck repeatedly during printing

I had the Same issue today. with about 15 stuck filament errors during one print. I have the printer since september, first time this issue occures.

RE: Filament gets stuck repeatedly during printing

I am also experiencing the same problem, a "Stuck filament error", which is not solved when unloading and reloading the filament. Initially I thought it was due to me using a 2kg spool of filament from a reprack. I thought the spool was too heavy and pulling filament off it was putting too much strain on the machine - nope. Tested a 1kg spool on the Prusa spool holder and I get the same error. However, I only got this when using PETG, PLA seems fine. 

RE: Filament gets stuck repeatedly during printing

I've been printing just fine for a week, but had a weird issue where it shifted everything +Y by 10mm, then devolved into a string mess. After that, I can't get it to finish a print without getting a stuck filament error. I just produced three bonkers benchies with the default galaxy black pla, and all three gave me the stuck filament error on exactly the same layer. Weird.

RE:

I went back to the normal, not high speed, nozzle and all is gine again. I mostly print PETG.

RE: Filament gets stuck repeatedly during printing - Any Updates

Hi All,

I got a new MK4S + MMu3 fully assembled, but wanted to try the printer without MMu3 to test that it worked. I set it up with the spoolholder and Prusa PLA and tried the 8 min benchy that was on the provided thumb drive. I had filament stuck happen two - three times during print. This happened on two consecutive prints.  I then printed the spatula with no issues and tried benchy again, twice. Same issue happened. I tried the 14 min benchy and it also had filament stuck issue. 
I reached out to support and after 1 hour wait to get rep, I added some info and got disconnected. After another hour wait in queue and then connecting and trying multiple things that were suggested (including auto cold pull several times), issue wasn’t fixed. It was recommended that I get new firmware upgrade and did so using wireless download, and per recommendation deleted older file.

I then got disconnected from rep again (2.5 hours in) and decided after the flash to try printing benchy again (did not re-run calibration as it’s not required). I got crash error 🙁 I then decided to do recalibration and can’t get beyond loadcell test. Initial calibration did require multiple tries to get loadcell test to pass but now I can’t get it going at all.
I will try support again tomorrow as it’s past midnight now, but was anyone here able to get beyond stuck filament issue? My MK4S has the original nozzle as that is default when getting it with MMU3 assembled version.

RE: Filament gets stuck repeatedly during printing

Disable the Stuck Filament check in the printer's LCD menu. I had this on one of my Mk4S's, and after disabling it it's been printing flawlessly. I know it's a kludge but it worked for me

RE: Filament gets stuck repeatedly during printing

I then decided to do recalibration and can’t get beyond loadcell test. Initial calibration did require multiple tries to get loadcell test to pass but now I can’t get it going at all.

This helps me confirm the loadcell for many people's issues. At some point (not sure which firmware) Prusa quietly enabled using the loadcell to judge the nozzle pressure and then using that to detect nozzle jams. If the loadcell is acting up (or if you are getting small bits of dirt dragged into the nozzle by the filament) then you'll see stuck filament errors along with filament changes at random times during a print.

If you can't get past the loadcell test, are you able to do a mesh leveling (experiment with an already damaged build-plate or something hard on top of your good build plate like a clipboard or something)?

Check the loadcell connector on the side of the Nextruder. Unfortunately, if the loadcell is bad you'll have to swap out the metal frame/heatsink of your Nextruder.

RE: Filament gets stuck repeatedly during printing

Experiencing filament jams after upgrading to the MK4S can be frustrating.Even if the nozzle appears fine, internal obstructions can cause jams. Performing a cold pull or replacing the nozzle has resolved similar issues for others.

RE:

Thank you for the information @sembazuru and @lily-clark. I was on chat with a different support person last night, and tried multiple things including additional cold pulls with problem still persisting. I was also asked to check loadcell cable and connector and I didn’t see anything and rep didn’t see anything abnormal from pictures I sent. I sent a picture of the nozzle as to me it seems somewhat abnormal - I see what looks like a divot in it but rep said it looks OK. Picture was taken upside down so is not the clearest, but I would expect this nozzle to look like the high flow one which doesn’t show any abnormality. Can you all let me know if your nozzle looks symmetrical with no divots or shadows? This is the original 0.4 nozzle.

RE: Filament gets stuck repeatedly during printing

Mine is original brand new factory assembled MK4S so it’s not a tool upgrade issue. I posted additional details but no fix yet. I will post if/once I get resolution.

RE: Filament gets stuck repeatedly during printing

hi,
I gave up. The filament jammed during every print, every single one! The time I spent on it, the nerves… I removed the high-flow head and installed the old obsidian one. And the filament jam problem ended immediately. The high-flow head is a disaster. They have to fix it.

RE:

Just got an mk4s (factory assembled) as my first filament printer - running into the same repeated "stuck filament detected" error in all of my (attempted) prints.  Based on this thread, doesn't sound like there's any obvious fix, which is frustrating.  Adding a couple of other details based on my experience, in case that triggers any lightbulbs.

First, I had a repeated failure of the XYZ calibration during the self-test, during the Y test.  Eventually it passed without any intervention on my part.

Second, my "stuck filament" errors seem to correspond to misapplication of filament as shown in the pictures below.  (From the bottom, those show my first, second, and third attempts at the keychain benchy, and then my first and second attempts at a fidget from thingverse).  I figure it's messing up on application due to the stuck filament, but am wondering if maybe it's the other way around - filament is not getting laid down properly for some reason, and is then causing a backup and blockage within the extruder?  

As noted, I'm brand new to PLA printing (and pretty much brand new to 3d printing generally) so I may be missing something obvious.  Curious if anyone has any thoughts.

RE: Filament gets stuck repeatedly during printing

Welp, turns out I'm an idiot - I was using PETG rather than PLA, but hadn't adjusted settings.  Replaced with a PLA spool and everything running fine.

RE: Filament gets stuck repeatedly during printing

Been there, Done that... probably do it again some time!
take care

Joan

RE: Filament gets stuck repeatedly during printing

Hi @tombin, I’m glad you got yours to work.

RE: Filament gets stuck repeatedly during printing

Here is update for my issue.

Since I got the MK4S with MMU3 fully assembled, I have the standard nozzle installed on it. As per Prusa website “In the MK4S/MMU3 bundle, you will receive both nozzles in the package - the standard one as well as the high-flow nozzle. For assembled MK4S in a bundle with MMU3, the standard nozzle will be pre-installed on the printer as the default”. I also double checked that the other nozzle is the high flow nozzle - it’s listed on the bag.

I did a hard reset and calibration and this time I was able to pass the loadcell calibration test again. However printing test showed the same problem again - filament stuck error.  I was sent a replacement hotend heatsink due to customer support thinking loadcell was bad and I did one more troubleshooting step. I followed the additional instructions listed for “Loadcell Measure Failed”.  I went beyond inspection of connector and cable (which I did previously based on customer support recommendation) and did the loadcell white pad visual check which are listed as steps 1, 2 and 3. I was surprised that my installed heatsink seems to have a black pad rather than white, and it seems to have some damage. 

I don’t have the PG-assembly-adapter since I bought fully assembled unit and replacement hotend heatsink doesn’t have the filament sensor installed. The heatsink unit I received had loadcell cable but not the filament sensor installed. This is supposed to be all-in-one unit for MK4S, based on Ifti’s Tech Corner youtube channel MK4S assembly instructions. I don’t know if the pad is the problem or if it’s something else and don’t want to spend a lot of time trying different things and then hoping it will work.

Customer support finally got back to me by email, and they don’t want to send a replacement but said I could send printer back for repair. They listed they have a long queue and it will take some time to get it back. If I send it back for repair, I will exceed the 60 day return window since I’m in the US, so I have asked them to start the return process. Unfortunately, it seems my printer is one of the problematic ones, so don’t want to end up with non-functioning and expensive “paper weight”.

I am disappointed as I really wanted this to work as it seems like Prusa is a good company and I wanted to support them based on all they’ve done for 3d printing. It seems that a large majority of customers have a great experience with the printers they receive but I find I’m in the minority group - part of those who struggle with problematic printer.

I added some pictures here,  if anyone runs into same issue and want to have it as reference. I can’t get really good resolution but seems like besides the pad being black rather than white, the pad has some bumps on it.

RE: Filament gets stuck repeatedly during printing

Just finished building my MK4S kit and hit the same snag referred to in this thread - stuck filament. I'm reasonably mechanically competent and pretty sure I built everything exactly as described - all setup tests and calibrations passed first time. I tried to print the bonkers benchy with the supplied black Prusament PLA sample but it failed badly due to the filament getting stuck and almost nothing coming out of the nozzle and I got the same clicking others have described. I'm new to 3D printing and this is my first ever printer so naturally I suspected I had done something wrong  - I checked the following:

• Idler latch tension screws - tightened and loosened - looser was better with the screw ends not quite coming to flush with the end of the threaded recesses
• Did a cold pull
• Removed the nozzle to check for deformations thinking maybe I had overtightened the thumbscrew retainers - perfectly straight and undamaged so reinserted
• Changed to the supplied Grey PLA - loaded, purged until all seemed ok with filament being extruded with no clicking
• Bonkers benchy failed again - just string hair with blobs - so, cleaned up, cold pull again
• Re-ran the gear alignment routine and as it ran I saw small chunks of squished filament stuck to the gear - see video - I stopped the gear alignment midway so I could get the chunks out with a toothpick, then reran the gear alignment from scratch again.
• This time I went for the spatula test print included on the USB - accepted all the defaults but noticed the same quality issues developing as the print proceeded - hair instead of proper extrusion. I figured it was not heating the incoming filament fast enough for the speed it was trying to print at so I dialled the speed back from 100% to 50%. BINGO! Well almost, there were still some surface flaws but at least I now have a useable spatula - just got to print another one to get the first one off the print bed 😉

I paid the Prusa premium because I'm a newbie and wanted to begin my journey with the highest chance of a good first experience. How did chunks of PLA get squished onto the gears? It's obviously above the hot end so it shouldn't be melting. If it's the Idler latch tension being set too high, thereby causing too much friction with the filament and the gear which is grinding chunks off the filament instead of pushing it through the hot end, I would say that's a design issue isn't it?? Surely there is a filament drive mechanism that is less sensitive to blind fine manual adjustment of a couple of tension screws and one more durable/reliable over time? Running everything at 50% speed seems like a poor compromise that defeats the purpose of the "S" in MK4S too - what am I getting wrong here Prusa?

RE: Filament gets stuck repeatedly during printing

If you want an answer from Prusa, Contact Prusa chat and refer them to this thread. 

that way, you are directly referencing the Prusa Support team. 
regards Joan