Can not remove filament - no movement in any direction
Hi I can not remove a filament from my Prusa i3 MK3S.
The following solutions I tried:
- open up the crew at the extruder to verify, if the extruder gears are rotating. Yes, they rotate.
- heat up the nozzle and check if I can move the filament. No, no movement is possible. No movement in any direction.
- disassemble the nozzle and check by visual inspection if the nozzle is clogged. No the nozzle is not clogged.
- Checking the heat block temperature with laser infrared thermometer. Showed tempertures between 100 and 150 degrees. Maybe not correct because the laser point did not really match the best surface to measure.
Any idea I can check?
Note:I will not buy and additional assembled heatblock with cables, because 2-3 months ago I damage the heat block and the electrical cables were brocken.
Before distorying the next part on a 4 months old Prusa i3 MK3S, I asked for your support.
Best Answer by --:
Something you are doing is causing the issue; you should really try to figure out what that is before moving on.
We aren't there to watch how you print, so it is up to you to figure out what steps you are taking that results in a hot end failure like this. What ever it is, it is a major mistake, because these types of filament jams are not normal.
If heating the nozzle to 280c doesn't allow filament removal, then disassembly is the only option. Follow the Prusa guides to remove the heat sink assembly, you might be able to remove the filament after removing the PTFE tube from the collet.
If not, follow the E3D-V6 guides to disassemble the nozzle from the heater block (must be done at 285c), the heat break from the heat sink and heater block (can be done cold), and then I'd recommend replacing the heat break with a stock E3D-V6 version rather than reusing the Prusa version (just guessing the heat break is part of the problem).
With no pictures, and just your few words to go on; I am 100% guessing as to the problem; so take my comments as loose suggestions.
But technically, it is almost impossible for filament to be that stuck, to where pulling it up through the extruder won't work. The PTFE will expand to let 2.2 mm filament pass through. Only if the PTFE wasn't installed correctly AND you aren't using the cooling fan AND the entire heat sink reaches 150C can you get filament to expand into the PTFE socket such that it won't pull out. Only full disassembly can fix that set of conditions.
And that doesn't mean the hot end is bad; it just means it wasn't assembled correctly. Which by the way is pretty common when folk don't carefully follow the manuals and guides. There are MUST-DO steps, that if skipped cause exactly what you seem to be experiencing.
RE: Can not remove filament - no movement in any direction
There are several contradictions in your statement. But starting with the premise filament won't unload after a print.
Ignore your IR thermometer - it is useless for measuring the nozzle temp. Besides emissivity of metals, the area it measures is rather difficult to pin down: lens focal length, sensor size, parallax to the laser, etc.
If you preheat the nozzle to 280c, then select UNLOAD filament, what happens?
Also, what type of filament are you printing?
RE: Can not remove filament - no movement in any direction
Hi Tim-m30,
I actually used Prusament PLA.
Based on your input, I heat up the nozzle to 280 degree and unload the filament. No filament were unloaded. As before the Prusa filament is totally fixed in the extruder. No movement possible.
The extruder gears (both front and back) rotated, but had no impact. Don´t see any marks on the filament or dust from a slippage.
I try to upload a short video, if possible and helpful.
RE: Can not remove filament - no movement in any direction
At 280, the PLA should have been dribbling out the nozzle. Was it?
Try using the acupuncture needle inserted through the tip. It may break up a clog.
With the bondtech gear disengaged (loosen the idler screw), pull - hard - on the filament with hot end at 280. Just try to not break the filament...
If anything I say contradicts Tim - listen to him.
RE: Can not remove filament - no movement in any direction
Hi Robert-rmm200,
thanks for your comment. I tried everything following Tim recommendation.
I will assume the problem ist not in the nozzle. It seems the problem is at the PTP tube, heatsink and heatbreak.
If I don´t find any solution I need to buy a other assembled hotend E3D at Prusa shop. But this is then my second new hotend within 4 months.
What a ... So I'm looking for help and support.
RE: Can not remove filament - no movement in any direction
Something you are doing is causing the issue; you should really try to figure out what that is before moving on.
We aren't there to watch how you print, so it is up to you to figure out what steps you are taking that results in a hot end failure like this. What ever it is, it is a major mistake, because these types of filament jams are not normal.
If heating the nozzle to 280c doesn't allow filament removal, then disassembly is the only option. Follow the Prusa guides to remove the heat sink assembly, you might be able to remove the filament after removing the PTFE tube from the collet.
If not, follow the E3D-V6 guides to disassemble the nozzle from the heater block (must be done at 285c), the heat break from the heat sink and heater block (can be done cold), and then I'd recommend replacing the heat break with a stock E3D-V6 version rather than reusing the Prusa version (just guessing the heat break is part of the problem).
With no pictures, and just your few words to go on; I am 100% guessing as to the problem; so take my comments as loose suggestions.
But technically, it is almost impossible for filament to be that stuck, to where pulling it up through the extruder won't work. The PTFE will expand to let 2.2 mm filament pass through. Only if the PTFE wasn't installed correctly AND you aren't using the cooling fan AND the entire heat sink reaches 150C can you get filament to expand into the PTFE socket such that it won't pull out. Only full disassembly can fix that set of conditions.
And that doesn't mean the hot end is bad; it just means it wasn't assembled correctly. Which by the way is pretty common when folk don't carefully follow the manuals and guides. There are MUST-DO steps, that if skipped cause exactly what you seem to be experiencing.
RE: Can not remove filament - no movement in any direction
Dear all,
many thanks for all your feedback. After my vacation an some additional distance I fixed the problem:
- Cutting the filament 10 cm over the extruder
- Pull heavily the rest filament out of the extruder at the heated nozzle of 280 C Celsius.
- It was very strong with small movement, but successful.
- Enter new filament also at 280 C Celsius and start the Auto-Load. Then reject two-times the question - "Is this the correct filament color?" After a while I got a smooth filament extrude.
Then re-load two time the new filament and try to do several Cold Pulls.
RESULT - Prusa i3 MK3S works perfect.
RE: Can not remove filament - no movement in any direction
Good to hear it's working again. Often people load one type of filament thinking it's another type (loading ABS spool thinking it's PLA). Something we've all done. And it sets you up for problems like this - stray bits of higher temp material in the heat break and nozzle.
Another cause is using odd materials like glow in the dark or carbon or metal filled filaments. They also leave bits and pieces that can cause problems days or weeks later. Cold pulls are almost a necessity after using them. Many experienced users have cleaning filament on hand and use it religiously after every filament change just to avoid these problems.
If you have this happen again, try to think back to your last few prints. Perhaps you can identify what it was that caused the problem in the first place.
ps: you might want to verify that after pulling the stub up through the PTFE the PTFE is still in place: and not too high and feeding into the Bondtech gears. It's probably okay, but worth checking.