Flament wont come out
Hi Folks,
I am new to 3d printing. Finally i have had a chance to build the MK3S i purchased a 1.5 year ago this month. I was able to successfully calibrate and print various prints. And then i have encountered a problem where Flament (grey flament that comes with the prusa) wont come out of the nozzle anymore. I think either nozzle or tube might have got clogged. I do not have a 1.5 mm 10 cm steel rod so i used the smallest allen wrench to go as much as possible from the top to clear out anything. then i tried the acupuncture needle for the nozzle. it appears areas i was able to reach is clean. I have tried various methods like increasing the temp to 285 etc. No luck. What would be a good next step for me? remove nozzle? remove hotend? i do not want to disassemble extruder if possible. I did open the door on the extruder and ensure there are no visible residue, i was able to insert the flament into tube. i think it is getting stuck somewhere close to nozzle
Here is what happened chronologically
1. Printer works fine.
2. During a long print i discovered there was a knot in the flament. Nozzle was printing empty. I immediately cancelled it. Unload the flament.
3. Update firmware from 9.* to 11 something latest i believe.
Any tips are appreciated
thanks
RE: Flament wont come out
after removing the hot end from the extruder per instructions, i have noticed PTFE tube is clean. and heat break had some debris in it. i cleaned it and now i will assemble back again. i have learned in a video this could happen if machine got turned down while the hot end is hot. and never to that. was there a warning somewhere for this? i might have missed it.
RE: Flament wont come out
My frustration continuous now i get preheat error when i put the hotend back to extruder. however if i take it out and let it hang outside of extruder, it heats up fine. i have made sure thermostat cables are above the red ones. Any ideas what could be the problem? So far my experience with Prusa is one problem after another unfortunately. really disappointed.
RE:
Sounds like a clog. Before disassembling everything I'd try cold pulls. Just Google for it and check the Prusa knowledge base.
I haven't had any clogs in ages that were not of my own making (such as not purging hot temperature filament such as PC properly before printing with low temperature filament such as PLA). You may not be printing hot enough for the filament you're using.
I have learned in a video this could happen if machine got turned down while the hot end is hot.
I call BS on this one. I turn my printers off all the time while the hotend is hot. Never had any issues.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
During a long print i discovered there was a knot in the flament.
Never let go of the end; if the end slips under the crossover slips round the spool, tightening slowly, until it binds an hour or so later.
Nozzle was printing empty.
And the last vestige remaining in the hotend was baked to cinders.
You *might* shift it by opening the extruder idler, set the temperature to a few degrees above printing temperature and then feed filament through by hand - push down firmly and with luck you will force the clog out. If this doesn't work try cold pulls. If the cold pulls don't work remove the nozzle and repeat the above procedure.
Cheerio,
RE: Flament wont come out
Thank you for the replies. Clog was in the heatbreak and now it is removed and everything put back together. I did find the reason for the preheat error as well. It was because i screwed heatsink too close to the heater block, they were actually touching each other, as a result, fan and the heatsink works as a great cooler and prevent hotend from going above 150 c. it is funny actually. What was frustrating nowhere in the instructions this is called out (especially for newbie like me) that they should NOT touch and there should be some X length separation between the two. It is implied in the pictures, but never called out. I found the v6 wiki instructions better.
I think there are two safety features missing in the printer. I wish they were implemented (if possible). 1. stuck filament detection and pause the printer immediately. 2. nozzle running empty
RE: Flament wont come out
Glad you found the source of your problem and you're back to printing.
In step 25 of the heat break replacement instructions ( https://help.prusa3d.com/guide/how-to-replace-a-heatbreak-heatsink-heaterblock-mk3s-mk3s-mk2-5s-mmu2s_16104) it says:
Screw the nozzle slightly in the heaterblock. Create a gap about 0,5 mm (0.02 inch), see the picture.
With the other hand, screw the heatbreak with heatsink into the heaterblock from the opposite side until it touches the nozzle inside
By screwing the nozzle in and creating that small gap, you'll get the optimal position for the heat break and heat sink.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Flament wont come out
In step 25 of the heat break replacement instructions ( https://help.prusa3d.com/guide/how-to-replace-a-heatbreak-heatsink-heaterblock-mk3s-mk3s-mk2-5s-mmu2s_16104) it says:
Screw the nozzle slightly in the heaterblock. Create a gap about 0,5 mm (0.02 inch), see the picture.
With the other hand, screw the heatbreak with heatsink into the heaterblock from the opposite side until it touches the nozzle inside
By screwing the nozzle in and creating that small gap, you'll get the optimal position for the heat break and heat sink.
Oh, they have changed the instructions, if only they had done that before I had to work that out myself 😉