Printer Not Unloading filament
Hello to whoever see's this post.
while the printer is not one I own (it's a school i like to visit) I helped get a mk3 settings right. i noticed that when the printer tried to extrude that no filament was being pulled into the printer and there was a audible clicking noise coming from the extruder. when trying to unload filament the printer would make said clicking noise again, much faster from the filament being pulled. when trying to manually pull the filament out (grabbing the filament and pulling on it without telling the printer to pull it out) it would not move. i had the nozzle heated up. from what i've read this is caused by a clogged nozzle. i'm hoping i don't have to pull the extruder assembly apart, as i also have to help fix another printer that has some issues (i don't know what the problem is on that one. the one i'm talking about here, the issue was discovered while i was there) that i also intend on helping fix
the issue was discovered when the printer wasn't laying plastic down on the build plate. plastic is sticking down and the layer height was at .2 mm for the first layer. from what i can tell, the leveling process was successful in leveling the printer.
this printer is not mine, and is a school i visit. the teacher there has been the teacher of this class for less than a year and i've had more time to mess around with other printers than he has. i don't own a prusa printer myself, but i do own variations based on the prusa printers.
thanks to anyone who read through all that and bigger thanks to anyone who reply's and helps me figure this all out.
RE: Printer Not Unloading filament
I had a problem like this and it did require me to remove the hotend. First though, I was able to remove the filament, I just could NOT load it (the clicking noise would happen).
Once I had the hotend removed, I used a large unfolded paperclip to push up through the hotend hole. This caused a nasty chunk of filament to pop out.
I am not sure if this was really the smartest approach, but I can tell you this has happened 2 times since then and the process has worked fine each time (note: you should be able to push a paperclip all the way up and see it come out the top, near the feeder gears).
Hope this helps!
RE: Printer Not Unloading filament
Dear David:
thanks for the reply! i'll make sure to try this once i arrive at the school to fix it. i have some nozzle cleaners, so hopefully i won't have to use a paper clip. i've read that heating the nozzle up to 260c will also work well. and from what i've read, 2 screws will have to be undone to pull the filament out. thanks again!
RE: Printer Not Unloading filament
Nozzle jams are somewhat common: a quick fix is often to heat the nozzle to 260c (for PLA), let it sit a couple of minutes and then extrude or open the idler door and manually push filament through. It clears most jams.
If that fails, the next step is a cold pull. Let everything cool down, nozzle should show less than 30c. Open the idler door so gears aren't engaging filament. Set the nozzle temp to 90c, and immediately start pulling upwards on the filament coming out the top guide. The force of pull shouldn't be enough to lift the printer, but close. At some point the filament will start stretching and then come loose from the nozzle. The end of the filament should be formed like a rocket nose cone, and if you do it right there will be a tiny 0.4mm tip at the end. Sometimes it takes a couple of tries to get the nozzle clean. And there are cleaning filaments that make the process a bit easier and more friendly.
RE: Printer Not Unloading filament
I've read the guilds in fixing this. That will be my first thing to try in fixing theissue. Next is the cold pull. If both of those fail I'll try seeing if replacing the nozzle works. Hopefully I can get it fixed.
RE: Printer Not Unloading filament
Jacob:
Good advice to follow above. If I could add a helpful tip to assist with cold pulls and hotend maintenance, since you indicate it is a school printer, is the video 54 seconds in for the correct idler screw adjustment. I noticed that if the idler screws are too tight it will click on filament feeding. It is a very helpful video. I make sure to run some ESun cleaning filament through whenever switching types of filaments and find that it greatly reduces clogs/issues FWIW.
I know you said that you read the guides, I put a link in in case anyone else stumbles on the post since the move to the new forum site is not easy to reference the Knowledge base articles. Links to the knowledge base articles on cold pulls https://help.prusa3d.com/article/lnbcnhg76k-cold-pull and hotend clogs https://help.prusa3d.com/article/WWVRzOY1dX-clogged-nozzle . since it is a very common issue.
I hope you get it worked out!
Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!
RE: Printer Not Unloading filament
Dear jbinfl:
thanks you for sending the video. From what I've seen, the teacher that has gotten the printer for the school is still learning about 3d printing and maintenance in general. I offered to help out a little since I had done some more time working with my own printers and tinkering with them. He hasn't had much time to tinker around with stuff since he has to teach students. I am fully aware of how to do a cold pull. the printer seems to be fine in regards of print quality. The only part of the MK3 I wasn't aware of was the 2 screws holding the filament in. I know i'll have to take them out to do proper maintenance.
As of when I'm typing this out, I will be leaving to fix the printer in about 1 hour. hopefully I have all I need to fix his printers and get everything up and going for him.
RE: Printer Not Unloading filament
The filament tension is pretty simple. The starting point is to loosen the two screws until they are freely spinning, then screw them in until you feel them contact the spring (requires a light touch). You should see the screws threads are are flush with the nuts in the door (use a magnifier). Then, turn each screw two full turns. This is a good starting point.
The screws are probably too tight if the thread ends are above the door surface. It's a judgement call, and some filaments are softer than others, so adjustments may have to be made case by case, but too tight is almost as bad as too loose.
RE: Printer Not Unloading filament
Update on the printer:
I've tried heating the nozzle up to 260c and unloading, as well as manually pulling the filament out. This did not work. i tried doing a cold pull as well, still did not work. i suspect it is the heat break with either a heat creep, or the new design (as mentioned here: ) and plan to somehow reach out into support for help on this issue.