Filament is not coming out of the nozzle anymore
Hey everyone,
I'm super new here. I have had my Prusa MK2 for a while now, but filament stopped coming out of the nozzle mid-print today. The extruder servo is working; the display shows correct temperature on the hotend but nothing comes out. I pushed the needle inside the nozzle and it goes up so it seems the nozzle path is open. But when I take a piece of filament and push it into the extrusion hole, it seems like it gets stuck somewhere. I need to open the print head and figure out what is stuck but I was wondering if anyone can help me understand why this might happen!?
RE: Filament is not coming out of the nozzle anymore
How does the filament look after it attempting to extrude? I'm assuming it gets all chewed up and you cut the filament back to avoid that chewed up area; if it's not chewed up you may want to tighten down the tension screws there (the ones with the springs). if it is chewed up it could be a couple of things; I would remove the hot end and inspect the following parts, the heat break, if there is something stuck in the top part (that isn't the PTFE tube that could be your culprit (could allow something to pass through it if it is a much smaller diameter); make sure your PTFE didn't come out that it is not severely damaged (perhaps you tried a cold pull and pulled it out some).
RE: Filament is not coming out of the nozzle anymore
If the Mk3 is anything like the Mk3, you can try this:
- Raise Z so you have a clear view.
- Remove the fan cooling shroud.
- Heat to print temp and unload any filament.
- Open the extruder.
- Inset a 1.5mm X 150mm soft brass rod (from hobby stores. Charles used 1.6mm Tungsten welding rods) down through the top, past the extruder gears and into the PTFE above the heatbreak.
- If a gentle push doesn't work, increase hotend temp.
With any luck, you'll be able to push the blockage into the hotend where it will extruder. If this fails:
- Remove the nozzle per E3D instructions.
- Push the rod from below.
You should be able to grab the blockage as it pops out the PTFE tube below the extruder gear.
If this fails, an extruder tear down may be required.
If you don't find a blockage, check your filament feed path, including extruder idler and grub screws.
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RE: Filament is not coming out of the nozzle anymore
Using the needle to try to dislodge a jam is sometimes the quickest solution. I usually bump up the temperature 10-15 degrees to make the filament as runny as possible.
If that fails, I usually replace the nozzle as my next attempt. This usually fixes the problem for me. You have to recalibrate your Z-height so it takes a bit longer.
Steve
RE: Filament is not coming out of the nozzle anymore
Thanks to all of you for the great tips and help. I opened the print head assembly, and replaced the PTFE guide with a new piece. I think I had cold-pulled the ABS filament out of the PTFE and it had left residues. The new tube seems to have solved the problem. The printer worked for 6 hrs yesterday with no issues and a beautiful print. 😀
RE: Filament is not coming out of the nozzle anymore
Glad you're back in business. Happy printing with it!
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan