Extruder clicking and PLA filament jammed  

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niccolo.v
(@niccolo-v)
Active Member

Hello,
it's about one month I bought a Prusa i3 MK3S.

I'm experiencing issues with extruder: it starts clicking and then stops pushing filament out (it seems to be jammed). I can resume printing by unloading the filament, cutting the last piece and reloading, but I cannot leave the printer unattended for more than 30 min - 1h. If I leave the printer unattended during the night, I wake up in the morning and find that just the first 10 layers have been printed, extruder clicks, and printer is way above the printed layers "thinking" it's still printing, but no filament comes out (it missed all the layers).

I read that other users have the same issue, but I suspect that the main cause is the ambient temperature increasing (summer time), because I never had any issues before.

I will keep you posted about all the improvements on solving this problem. By now, I tried the following:

If you have any advice, not already tested, do let me know. I will also keep you posted about improvements.

Happy summer time printing!

 

 

This topic was modified 9 months ago 2 times by niccolo.v
Posted : 07/06/2019 5:19 pm
niccolo.v
(@niccolo-v)
Active Member

I'm updating this post with other tests I did:

  • I spent 2hr recalibrating everything, including temperature calibration.
  • double checked the first layer (if you are experiencing this problem I suggest to check that the nozzle is not too close to headbed for the first layer - the motor needs to push harder through the nozzle if it's too close to the heatbed and it could jam the filament after some hours of printing).
  • I read somewhere that printing with higher temperature (nozzle) would solve the problem: tried that, but no luck.

When I unload and reload filament, after the jamming, the end of the filament is larger than the rest. I suspect that the heat from the nozzle is spreading to the very first part of the PTFE tube, melting the PLA inside and jamming it. I will trying to decrease the temperature of the nozzle instead of increasing it.

This post was modified 9 months ago 2 times by niccolo.v
Posted : 08/06/2019 8:29 am
Tim
(@tim-m30)
Illustrious Member

Here's an image of filament pulled up after a certain type of jam.  Cut the end off and the print resumes without difficulty, until it jams again minutes or hours later. 

Does your filament look like this?

Left stubby side is down. 

 

It is always wise to get more than one opinion......
Posted : 09/06/2019 2:50 am
peter.m26
(@peter-m26)
Estimable Member

https://www.thingiverse.com/thing:2975582

I am printing in a enclosure, and the extrude gets to hot, and the heat travels to the filament.

For the summer a extra fan for pla printing in the enclosure, so only if needed, this one blows cool air in the bottom of the enclosure.

 

Then rebuild the heatbreak , tube, so you are 100% certain that it is 100% build,

search prusa forum and youtube movies, on how to.(very very very important),

I have the mk3 (no S), and changed the heatbreak to the e3d heatbreak, the prusa has a bigger width inside, this is needed for the mmu2, if this step is needed i do not know. Search youtube for this.

 

The 2 extra fans are needed, the extruder fan is very important it cools a lot, also for abs wen the doors are closed.

The second fan to blow in the enclosure, for the summer, and only for pla.

 

You could try with a table fan to blow fresh air in the printer, and then print pla, and see if it improves.

 

I have a extra power supply in the enclosure, for a air filter fan, extruder fan, enclosure fan(for summer pla), and i am thinking setting a extra fan for the part where the cable come together(ensy board ?), this part is still to hot i think. The power supply is outside the enclosure.

 

Posted : 09/06/2019 3:44 pm
niccolo.v
(@niccolo-v)
Active Member

The prblem seems to be completely gone if I set the nozzle temp at 200 instead of 215. I also reduced the speed down to 75%. With this configuration I printed a 20hr gcode, with no issues. 

Anyway I'm prining an additional fan case for the extruder ( https://www.thingiverse.com/thing:2975582 ).

I'm pretty sure there's an issue with heat isolation. The heat from the nozzle is spreading to the first part of the PTFE tube, melting the PLA inside it and jamming it.

Posted : 09/06/2019 6:03 pm
Tim
(@tim-m30)
Illustrious Member

It would be extremely difficult to get the heatsink area of the extruder hot enough to soften filament.  100c is hot.  You would be able to feel that air coming out of the extruder fan duct.  And the E-Axis motor hot enough to blister.  The filament coming out when doing a change would have damage and unmistakable artifacts.   A simple nub at the end is not such an artifact. 

When you try the extra fan ... use a 5v model similar to the hot end fan (low wattage) then you simply parallel the 5v wires and ignore the tach wire (2-wire connection). So the extruder fan will power up any time the hot end is warm; this will help keep the motor as cool as possible.

Be sure to come back and post the outcome of you test.  A couple of us are curious if this will help. 

It is always wise to get more than one opinion......
Posted : 09/06/2019 6:41 pm
niccolo.v liked
niccolo.v
(@niccolo-v)
Active Member
Posted by: Tim

When you try the extra fan ... use a 5v model similar to the hot end fan (low wattage) then you simply parallel the 5v wires and ignore the tach wire (2-wire connection). So the extruder fan will power up any time the hot end is warm; this will help keep the motor as cool as possible.

Be sure to come back and post the outcome of you test.  A couple of us are curious if this will help. 

ok thanks! I'll post results as soon as I'm ready!

Posted : 09/06/2019 6:44 pm
jennifer.c10
(@jennifer-c10)
New Member

Hi there:

I've had my prusa mk3 for > 1 year. I replaced the extruder with a new E3D version, and I'm having these same symptoms.  After the first layer of the calibration cube, I get no extruder output.

Reducing the temperature to 200 allows me to get further into the print, but underextrusion simply starts later. I'm unable to get even the wall thickness calibration cube to complete.

 

What ended up being the solution for you?

Posted : 20/01/2020 9:04 pm
timyoungenator
(@timyoungenator)
Active Member

Has anyone come up with a definitive solution for this problem? I am experiencing symptoms exactly like what the OP has described and I'm at a loss as to what to do. The work-around for me right now is to stop the printer as soon as I hear the clicking, unload the filament, cut off the expanded portion, reload filament and resume printing. But this simply isn't a viable solution for anything that will take longer than an hour or two to complete. 

Please help if you have any suggestions for me and others in the same situation.

Posted : 13/02/2020 4:53 pm
Robert-mm200
(@robert-rmm200)
Noble Member

Only thing I have read that seems to help, if you do not have the MMU, is to get the E3D V6 heat break without the Prusa specific recess.

It is not very expensive, and worth a try. It is what I would do:

https://www.amazon.com/Genuine-E3D-Break-1-75mm-V6-175-BREAK/dp/B077Y2MHW8/ref=pd_cp_328_2/131-3990191-3077338?_encoding=UTF8&pd_rd_i=B077Y2MHW8&pd_rd_r=a51084fa-68c4-4a45-a880-7483f92b4d6c&pd_rd_w=FXyuE&pd_rd_wg=jC1eI&pf_rd_p=592dc715-8438-4207-b7fa-4c7afdeb6112&pf_rd_r=CDZ16F5DQ3PC4MB90J1K&psc=1&refRID=CDZ16F5DQ3PC4MB90J1K

Posted : 13/02/2020 6:22 pm
timyoungenator
(@timyoungenator)
Active Member
Posted by: @robert-rmm200

Only thing I have read that seems to help, if you do not have the MMU, is to get the E3D V6 heat break without the Prusa specific recess.

It is not very expensive, and worth a try. It is what I would do:

https://www.amazon.com/Genuine-E3D-Break-1-75mm-V6-175-BREAK/dp/B077Y2MHW8/ref=pd_cp_328_2/131-3990191-3077338?_encoding=UTF8&pd_rd_i=B077Y2MHW8&pd_rd_r=a51084fa-68c4-4a45-a880-7483f92b4d6c&pd_rd_w=FXyuE&pd_rd_wg=jC1eI&pf_rd_p=592dc715-8438-4207-b7fa-4c7afdeb6112&pf_rd_r=CDZ16F5DQ3PC4MB90J1K&psc=1&refRID=CDZ16F5DQ3PC4MB90J1K

Thanks for that suggestion. In the reviews on Amazon people are mentioning thermal paste. Do you think I should be using thermal paste when installing this?

Posted : 14/02/2020 5:28 pm
Robert-mm200
(@robert-rmm200)
Noble Member
Posted by: @timyoungenator
Posted by: @robert-rmm200

Only thing I have read that seems to help, if you do not have the MMU, is to get the E3D V6 heat break without the Prusa specific recess.

It is not very expensive, and worth a try. It is what I would do:

https://www.amazon.com/Genuine-E3D-Break-1-75mm-V6-175-BREAK/dp/B077Y2MHW8/ref=pd_cp_328_2/131-3990191-3077338?_encoding=UTF8&pd_rd_i=B077Y2MHW8&pd_rd_r=a51084fa-68c4-4a45-a880-7483f92b4d6c&pd_rd_w=FXyuE&pd_rd_wg=jC1eI&pf_rd_p=592dc715-8438-4207-b7fa-4c7afdeb6112&pf_rd_r=CDZ16F5DQ3PC4MB90J1K&psc=1&refRID=CDZ16F5DQ3PC4MB90J1K

Thanks for that suggestion. In the reviews on Amazon people are mentioning thermal paste. Do you think I should be using thermal paste when installing this?

None on the nozzle. Check other references for where. I think just on the heat break threads. Maybe someone else will chip in where specifically.

Posted : 14/02/2020 5:31 pm
bobstro
(@bobstro)
Famed Member
Posted by: @timyoungenator

Thanks for that suggestion. In the reviews on Amazon people are mentioning thermal paste. Do you think I should be using thermal paste when installing this?

You only want to apply thermal paste at the top of the heatbreak where it screws into the heat sink. The E3D instructions cover this pretty well IIRC. It makes sense: You WANT improved thermal conductivity between heatbreak and heat sink to help shed any accumulated heat. You DO NOT WANT improved thermal conductivity between the nozzle/heater block and heatbreak in order to prevent heat creep.

You might consider using something like Slice Engineering's Boron Nitride paste between your heater block and the thermistor and heater cartridges in order to make future removal easier. In this case, you WANT improved thermal conductivity between these parts and the heater block, but they operate at temperatures beyond what most thermal pastes are effective. This is definitely optional. I've used it and it did make a partial hotend rebuild easier, assuming you keep the overall hotend free of accumulated filament.

 

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 14/02/2020 6:01 pm
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