Extruder jams/clogs up after printing a little bit of filament
After spending about 6 hours trying to figure it out, I'm stumped.
It loads and unloads filament just fine. The filament sensor doesn't work (always triggered for some reason), but that's probably an unrelated issue. When loading filament I can select no (as in the color isn't coming out correctly) to purge more filament and it all seems normal so far. But when I start a print, it will print ok for a bit and then plastic comes out of the nozzle in tiny specks and eventualy nothing, and you can hear knocking noises as the extrusion mechanism is trying to feed filament but something in the hotend is stuck. It seems to vary with how much it can print before it jams up. Below is a picture of a first layer calibration print:
If I unload and reload the filament, it clears the "clog", but it jams up again. I don't think it is a problem with the extrusion mechanism as if I try to help it by pushing the filament in as it is trying to extrude, it still doesn't work (nothing comes out of the nozzle). It definitely isn't a first layer offset issue as it starts out printing fine and then stops working. I don't think there's an actual clog as I changed the nozzle tip, and cleared out residue from inside the heat block.
RE: Extruder jams/clogs up after printing a little bit of filament
Bump
This is owned by a college robotics club. The club treasurer says we should just chuck the whole thing and order a new 3D printer as we have the budget, but to me it seems definitely repairable.
What a sad sight. Very little used, considerably abused, repaired but no maintenance and ... never mind. This is what happens when a printer is freely available to a bunch of novices and no-one looks after it.
OK:
First: https://help.prusa3d.com/en/article/i3-printers-regular-maintenance_2072
- by the look of the fan screws all screws and electrical connections should be checked.
Then a couple of cold-pulls to clear the hot end: https://help.prusa3d.com/article/cold-pull-mk3s-mk2-5s_2075
I see someone has damaged the heater wiring and jury rigged a new heater cartridge - presumably in clearing a blob-of-doom due to the filthy print sheet. Make certain the loose wiring can't interfere with full motion, if possible replace it correctly but mark that down as a do-after-everything-is-working job.
Thoroughly clean the print sheet with dishwashing detergent (Dawn/Fairy) and very HOT water, handle by the edges only; is the other side in better condition? Someone has savaged the side in the picture.
Redo the extruder idler pressure; it's hard to tell from the picture but the screw looks to be on the loose side: https://help.prusa3d.com/article/idler-screw-tension_177367
Finally re-run the first layer 'Z' offset calibration. Show us pictures of the result here if you're uncertain.
From the few scraps in your picture it looks like you should dry your filament before use.
Once the machine is working attach a strict admonition to keep the print sheet clean and maybe supply rubber gloves as a reminder.
Cheerio,
RE: Extruder jams/clogs up after printing a little bit of filament
What a sad sight. Very little used, considerably abused, repaired but no maintenance and ... never mind. This is what happens when a printer is freely available to a bunch of novices and no-one looks after it.
It's mostly me and another guy that does stuff with fixing the 3D printers.
The heater and thermistor wires are like that because I removed the hotend hoping to heat it up and unclog it. I didn't bother to clean up the wires yet. Someone did replace the heater a few months ago due to a damaged wire though.
We already tried doing cold pulls and even replaced the nozzle tip, which didn't solve the problem. I can't tell if the clog is occurring before or after the nozzle, nor can I think of a possible reason it is recurringly clogging. Especially that unloading the filament and reloading temporarily fixes it.
A few months ago someone tried printing with very moist nylon filament and that was the first time we had this problem with it jamming up. I'm not sure if that was the cause, but we never had this happen until that incident. Since then, it would sometimes jam up mid print (with good PLA). But now, I can't even print the first layer. Z axis leveling is definitely not the issue because I tried testing it printing in midair hoping to get spaghetti the first layer, but it will stop making spaghetti after a minute.
RE: Extruder jams/clogs up after printing a little bit of filament
Remove the heatsink Remove ptfe tube and remove heat block (heat up then unscrew be careful ) then have a look do you see any blockages in the heatsink also DO THIS FIRST do this with pla leave it sitting at 230 for 20 minutes then try load then cool it down with fillament in then heat to 195 as soon as it hits 195 attempt to unload
What a sad sight. Very little used, considerably abused, repaired but no maintenance and ... never mind. This is what happens when a printer is freely available to a bunch of novices and no-one looks after it.
It's mostly me and another guy that does stuff with fixing the 3D printers.
The heater and thermistor wires are like that because I removed the hotend hoping to heat it up and unclog it. I didn't bother to clean up the wires yet. Someone did replace the heater a few months ago due to a damaged wire though.
We already tried doing cold pulls and even replaced the nozzle tip, which didn't solve the problem. I can't tell if the clog is occurring before or after the nozzle, nor can I think of a possible reason it is recurringly clogging. Especially that unloading the filament and reloading temporarily fixes it.
A few months ago someone tried printing with very moist nylon filament and that was the first time we had this problem with it jamming up. I'm not sure if that was the cause, but we never had this happen until that incident. Since then, it would sometimes jam up mid print (with good PLA). But now, I can't even print the first layer. Z axis leveling is definitely not the issue because I tried testing it printing in midair hoping to get spaghetti the first layer, but it will stop making
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
If there is a chance that there is a clog with high temperature filaments then unclogging must be done at the higher temperature.
[Changing filament must also be done at the higher temperature and purging completed before letting the hotend cool to printing temperature.]
Do this before diassembling as @hello suggests above, it may save you that step.
Loosen the idler. Heat to 265 degrees (hotter if the nylon specifies) and manually push at least 30cm of your regular filament through the nozzle, let it cool and do another cold pull.
Now reset the idler and try printing.
Cheerio,
RE: Extruder jams/clogs up after printing a little bit of filament
If there is a chance that there is a clog with high temperature filaments then unclogging must be done at the higher temperature.
[Changing filament must also be done at the higher temperature and purging completed before letting the hotend cool to printing temperature.]
Do this before diassembling as @hello suggests above, it may save you that step.
Loosen the idler. Heat to 265 degrees (hotter if the nylon specifies) and manually push at least 30cm of your regular filament through the nozzle, let it cool and do another cold pull.
Now reset the idler and try printing.
Cheerio,
I was more thinking heat creep so that's why I said go high temp leave it to sit then low temp and instantly pull out
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
RE:
I was more thinking heat creep
I thought so - but once we knew that nylon had been used high melting point residue becomes much more likely - 'though if that's not it you might turn out to be right in the end... We must suspect lack of maintenance and noobie errors more than usual in this case.
Cheerio,
RE: Extruder jams/clogs up after printing a little bit of filament
I was more thinking heat creep
I thought so - but once we knew that nylon had been used high melting point residue becomes much more likely - 'though if that's not it you might turn out to be right in the end... We must suspect lack of maintenance and noobie errors more than usual in this case.
Cheerio,
Yeah true but the fact it loads fine is pointing to heat creep but you could be right
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
RE: Extruder jams/clogs up after printing a little bit of filament
I took the nozzle and heatsink off the hotend and cleaned the melted plastic out of block very well.
I am leaning towards the issue being heat creep because the filament sometimes unloads looking weird on the end. I'll take a look when I get back on Monday.