Extruder clicking and PLA filament jammed  

RE: Extruder clicking and PLA filament jammed

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.

RE: Extruder clicking and PLA filament jammed

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. 

RE: Extruder clicking and PLA filament jammed

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.

RE: Extruder clicking and PLA filament jammed

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.

RE: Extruder clicking and PLA filament jammed

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. 

RE: Extruder clicking and PLA filament jammed

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!

RE: Extruder clicking and PLA filament jammed

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?

RE: Extruder clicking and PLA filament jammed

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.

RE: Extruder clicking and PLA filament jammed

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

RE: Extruder clicking and PLA filament jammed

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?

RE: Extruder clicking and PLA filament jammed

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.

RE: Extruder clicking and PLA filament jammed

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.

RE: Extruder clicking and PLA filament jammed

I to have this problem. 
It does appear like heat creep, but I cant believe a Prusa would have such a design problem.  It should just work right?
I have noticed the Extruder motor gets very hot - 48C, Ive seen 50C.  Maybe it gets hotter when I'm not looking - ive read this can pre-melt the filament so it melts too soon.  Again it seems hard to believe a Prusa would do this.

I need to solve this, quickly.  Tried all the above advice.

RE: Extruder clicking and PLA filament jammed

Okay so this video by the Printer Nerd sheds new light on this problem - and its a doozy. 

Im starting to think this printer is a lemon.  So you have to print way hotter than normal for it to work

RE: Extruder clicking and PLA filament jammed

Posted by: @3dprint-3

Okay so this video by the Printer Nerd sheds new light on this problem - and its a doozy. 

That video is about a year old now, so not exactly news. Many of the problems are related to cooling and retractions. I've never experienced the problem recently, but I do a lot of calibration of settings to avoid over-running the printer's capacity and to minimize retractions in the 1st place. When I had to replace my heater block, I went ahead and upgraded to a titanium heatbreak and nickel-coated heater block. Other things that have helped:

• Avoid printing PLA in an enclosure in warm months. The E3D V6 is rated to 40C ambient. Above that and PLA can soften prematurely as the cooling efficiency of the air cooled hotend is reduced.
• Improve air circulation around the cooling fans.
• Replace the Prusa heatbreak with the 2.2-2.0mm step with an E3D equivalent.
• Verify the filament feed path is friction free. Inspect the extruder gear area to make sure everything is aligned.
• Verify the extruder idler gear rotates freely and hasn't become stuck.
• Use some thermal paste at the top of the heatbreak where it screws into the heat sink ... but not the bottom where it screws into the heater block.
• Reduce retractions, especially in high-detail areas. I've reduced de-retract speeds to 25mm/s.

Expect to see a surge in heat-related issues as many parts of the world move into warmer months.

Im starting to think this printer is a lemon.  So you have to print way hotter than normal for it to work

I routinely print a variety of layer heights with a variety of nozzle types and do not have to print at unusually hot temps. 200-210C for PLA works well. Considering the number of Prusa printers out there as well as those cranking away daily in the Prusa facility and I don't think you can write the design off as a lemon. 3D printing is not as simple as a toaster yet, and there are a LOT of variables that can impact printing. This isn't unique to Prusa and/or the Mk3 design.

RE: Extruder clicking and PLA filament jammed

Hi everyone, I've been having the same problem for months now. I have spent days going through posts and making adjustments to my printer and print files with no luck. For a while I had given up and was printing exclusively with PETG (no problems whatsoever) but I ran out of PETG these last few days after printing several face-shields and thought I might give PLA a try once again. I've got a i3 MK3S. Here is a list of everything I have tried:

- tried multiple brands of PLA

- dried a few of them in oven

- replaced my heatbreak with the original one from E3D

- I felt my extruder stepper motor was running hot so I added a fan to it with the CG-tech mod ( https://www.thingiverse.com/thing:2975582 ). It now runs cool to the touch.

- checked the extruder and idler gears for alignment 

- replaced the ptfe tube a couple of times

- tried printing at multiple temperatures

- played with the retraction length and speed

I've had no luck so far and the most frustrating thing is that I can print flawlessly with PETG. As a last resort I'm considering replacing my extruder assembly with a new one from E3D but that seems a little stupid given that 3D printers are fairly simple machines and I was able to narrow my problem this far. Any suggestions would be of great help! 

RE: Extruder clicking and PLA filament jammed

How long does it take to start jamming? 
Is it worse where there is a lot of retraction?
I typically use 0.4mm retraction on the Mk3S with PLA

regards Joan

RE: Extruder clicking and PLA filament jammed

Wen changing from petg to pla , (hot to colder filament)

make extruder the temp of petg, pul filament out of printer, leave temp high, insert pla, extrude pla to clean out the petg, then lower temp, extrude pla again.

Then you can start printing.

Check the springs off the extruder, make it press harder to the filament in little steps.(or give less pressure) Try different settings.

Also try to print slower,

try hotter 10 20 degrees to see if it changes.

RE: Extruder clicking and PLA filament jammed

@joantabb

Hi Joan, thanks for the reply. 

It usually jams around two hours in a print. I have been able to print Benchys (for example) but I also had the printer jam on the last half of a Benchy a few times. By a lot of retraction do you mean frequency or length of retraction? At a certain point I tried turning retraction off completely but had no luck there. Since it's been a couple of months since I was testing different retraction lengths and I didn't document it properly I will give a go at using 0.4mm retraction, turning it off completely and get back to you. 

Something I forgot to mention in my last post is that when I finished assembling my printer back in September 2019 I could print pretty consistently with the original Grey Prussament filament that came with the printer. I got to print 28 hour prints with no problem and in general, with other prints,  only had ocasional jams (though more that I have with PETG, I don't remember PETG EVER jamming on me). Around the time I ran out of the Grey Prussament I opened a White Prussament that I purchased with the printer and had a really hard time going through the spool. I would get jams more often than not. Subsequently I bought three other spools of two of PLA, from two different brands,  to test if the problem was the filament but had no luck with either. I don't have a completely clear picture but I think that by the end of the Grey Prussament spool I was already getting frequent jams, I don't think It was something as instantaneous as changing filaments and having problems exactly from that moment on. Also I think it's very improbable that I got 4 different bad spools of filament from 3 different respectable manufactures in a row. Maybe this helps in creating a more clear picture of the problem i'm having.

Once again, thank you for your reply I really want to get my printer working properly. I am a Architect and Industrial Designer and therefore rely pretty heavily in my printer being in it's best shape.