Filament stuck and not able to remove PFTE Tube  

RE: Filament stuck and not able to remove PFTE Tube

I also tried to push the filament through the tube with the nozzle heated to 260°

RE: Filament stuck and not able to remove PFTE Tube

Is the hot end still connected to the printer? 

Try unscrewing the heatsink, it should part company with the heatbreak
leaving the heatbreak in the heater block
the PTFE May stay with the heatsink, or it may pull through the heatsink and stay with the heatbreak

once you have the heatsink off, you will know what the situation is... 

if filament is jammed inside the PTFE you should be able to soften and remove it with a hot air blower, 

Make sure that the heat block, nozzle and heatbreak are clear, re assemble using either the cleaned PTFE or a new PTFE tube, 
You should have a replacement PTFE in your spares bag, 

https://help.prusa3d.com/en/guide/how-to-replace-a-ptfe-tube-mk3s-mk2-5s-mmu2s_21664

regards Joan

RE: Filament stuck and not able to remove PFTE Tube

Hi,

Thanks a lot for your answer.

everything is still connected if you mean the electrical wiring. 

I removed the heat sink end the tube is staying with the heat breaker. 

not sure how your next steps are meant ;): what part exactly should I heat up and where should I push or pull? 

thanks

dennis

RE: Filament stuck and not able to remove PFTE Tube

If you still have power, now might be a good time for oven gloves
make sure you have a sparePTFE Tube, 
Heat up the hot end, grab it with pliers or similar, remove PTFE and filament, let hot end cool on heat resistant surface, (Maybe oven gloves)

reassemble hot end, heat and as soon as nozel temperature is reached, test for extrusion by pushing filament through hot end manually If it works, remove filament and cool immediately. if no extrusion, remove nozzle and try again. 
Assuming the extrusion (PASS THROUGH lol)  now works, cool immediately

If pass through doesn't work your blockage was probably in the heatbreak in the first place... 

Clean and restore nozzle or fit new nozzle, taking note of installation instructions, 

Re assemble extruder and fans... 

Heat nozzle to hot tightening temperature and finally tighten nozzle. 

Do live Z adjustment
Happy Printing... 

Joan

RE: Filament stuck and not able to remove PFTE Tube

Posted by: @joantabb

If you still have power, now might be a good time for oven gloves
make sure you have a sparePTFE Tube, 
Heat up the hot end, grab it with pliers or similar, remove PTFE and filament, let hot end cool on heat resistant surface, (Maybe oven gloves)

reassemble hot end, heat and as soon as nozel temperature is reached, test for extrusion by pushing filament through hot end manually If it works, remove filament and cool immediately. if no extrusion, remove nozzle and try again. 
Assuming the extrusion (PASS THROUGH lol)  now works, cool immediately

If pass through doesn't work your blockage was probably in the heatbreak in the first place... 

Clean and restore nozzle or fit new nozzle, taking note of installation instructions, 

Re assemble extruder and fans... 

Heat nozzle to hot tightening temperature and finally tighten nozzle. 

Do live Z adjustment
Happy Printing... 

Joan

Thanks again.

What exactly is the "hot end" is it the heating block?

Any chance to do this without needing a new tube? I'll order spares, but don't have any right now... 😉

RE: Filament stuck and not able to remove PFTE Tube

@dehein2

the extruder contains various parts,
there is the Hot end (nozzle, heatblock, thermistor and heater, plus the lower part of the Heat Block, and half of the heatbreak, )
the other part is the Cold End,  (Half of the heatbreak, heatsink, PTFE and the Circlip!)

the Fan Blows on  the Heatsink

regards Joan

RE: Filament stuck and not able to remove PFTE Tube

@joantabb

Thanks again and sorry for asking again (I'm just still be bit confused and don't want to make things worse.

Part A:
1. I leave it diassambled as it is on this picture:

2. I heat it to 260° for PLA? (is there any risk to overheat anything?)

3. Pull out PTFE with fillament and let hotend cool

Part B:

4. I reassamble the hot end only? What does that mean? Just insert the PTFE tube again? Everything alse should be still attached, right? (so picutre above)

5. I pus the filament through the new PTFE tube right?

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One addtional question: As I'm going to order the PTFE tube again, are there any "must have" spare I can order with it right away? 😉

Thanks so much
Dennis

RE: Filament stuck and not able to remove PFTE Tube

@joantabb:  

perfect, thank you!

The only thing I still not sure about is your step:

”reassemble hot end, heat and as soon as nozel temperature is reached, test for extrusion by pushing filament through hot end manually I” 

what is there to re-assemble? I’m just asking because you wrote that the PTFE tube is not part of the hot end  

so should I try to manually feet filament without the tube?

RE: Filament stuck and not able to remove PFTE Tube

Posted by: @joantabb

Part A... 

you meed to be able to remove the PTFE and filament, options include
Yanking the PTFE out with Pliers (Risk damaging the Wires on heater/Thermistor) (No guaranett the Filamet will come out with the PTFE)
Heating the heatblock with a hot air blower, Should work ok, don't overheat the the wiring or the extruder housing
Heat with the built in heater and thermistor.(Assuming these are working there is no chance of disastrously overheating the heatblock)
As I suggested, remove the PTFE Immediately... then cool the hot end...   
In my opinion, using the integrated heater is safest. But make sure you don't burn yourself. these parts get hot
standard PLA preheat temperature should be OK. 215C

handle the parts carefully so as to not stress the wiring... 

this should leave you with the hole for the PTFE in the heatbreak, being empty awaiting the new PTFE

Part B

Here is the Prusa Knowledge base article on replacing the PTFE. which covers reassembling the extruder

If you correctly diagnosed that the blockage was in the PTFE, then there should be no problem after reassembling the extruder. 

You will need to check Live Z. before you start printing. 

Good luck, 

Joan

https://help.prusa3d.com/en/guide/how-to-replace-a-ptfe-tube-mk3s-mk2-5s-mmu2s_21664

@joantabb; I just changed the PTFE tube and seems to work fine now. Filament is extruded again.

I just have  one issue: I have a lot more strings than i used to have before.

One thing i also saw is that there is a small filament dot on every of the points where the printer does the bed leveling before each print. I never had that before...

RE: Filament stuck and not able to remove PFTE Tube

@dehein2

Can you post an image of the "dot"?

RE: Filament stuck and not able to remove PFTE Tube

@dehein2

Have you checked your live Z, since changing the PTFE?

regards Joan

RE: Filament stuck and not able to remove PFTE Tube

@joantabb; @cwbullet

Thanks you and sorry for not getting back sooner. I now redid the live-z and also changes the filament a couple of times. It seems to work perfectly fine again... maybe i was just to impatient

RE: Filament stuck and not able to remove PFTE Tube

@dehein2

Great news!