filament jam / PTFE tube removal problems  

Re: filament jam / PTFE tube removal problems

Once i found hard to remove the filament, it was because the temp of the extruder was only 230° which is quite low for colorfabb xt. The end of the filament having the shape of the inside of the nozzle and not being very soft made the thing harder. Perhaps that can help. Increase the temp before unloading?
I never had issues unloading (pla, petg, xt, abs) and i done ~10kg on the mk3.

Re: filament jam / PTFE tube removal problems

At this point, my problem is removing the PTFE tube... the filament is broken off inside.... can't reach it w/ needle nose pliers from either end.
The filamant in question was Prusa PETG, using Prusa Sliicr defaults for their own PETG

Re: filament jam / PTFE tube removal problems

I was wondering if you were able to solve this problem. I have the same issue. My filament is stuck inside the heatsink and will not come out. I tried higher temps, cold pulls, and pretty much everything else. It has some PLA silver bought from prusa stuck inside it. I used the temps recommended for it. I haven't had many problems until this one.

Re: filament jam / PTFE tube removal problems

Hi guys,

Does anybody resolve this issue?
I have this problem with MK3. At first, the printer worked flawlessly. But right now, I have a filament jam in 90-95% of prints.
I also switched to R3 extruder ( one of the successful prints).
I know, that the issue is not in the gcodes as I have tried several slicers or the original Prusa gcodes on the card for MK3.
No success. New PTFE tubes installed (as suggested on the support) but nothing is helping.
I did not have any issues like that with my MK2S with over 250days of pure printing time. And that was my start of 3D printing. Every issue I have had at that point was my own error, but I do not think, that this is the issue now.

Thanks guys.
Filip

Re: filament jam / PTFE tube removal problems

Hi ,

Same here , IT JAM ALL OF MY PRINT, I tried difference setting and fliment and nothing’s change ,

I think this is a defect for the mk3 and we would like to have an official solution!

Re: filament jam / PTFE tube removal problems

Without supporting information, it is difficult to pinpoint issues

can we please start with
Filament in use,
slicer Settings,
Picture of what's happenning?

regards Joan

Re: filament jam / PTFE tube removal problems

I can't for the life of my pull out this PFTE tube. I am afraid if I yank much harder it will break.

Edit: well... shit...

Re: filament jam / PTFE tube removal problems

try removing the stainless steel heatbreak then warm the thing in an oven to 150 c grasp it in an oven mitt and extract with pliers if that fails use a rod of metal that is just a bit smaller than the threaded section that held the heat break and again holding the warmed thing in your oven mitt and tap out the remains of your ptfe tube.

you will have to have a new ptfe tube and it will need to be repaired according to the instructions here https://manual.prusa3d.com/Guide/How+to+trim+PTFE+tube+-+MK2-S+MK2.5+and+MK3/500?lang=en
but I would use the instructions here at the e3d website https://e3d-online.dozuki.com/c/V6 when you reassemble it.

Re: filament jam / PTFE tube removal problems

or try a metal rod (about 1.75mm) and just push, I think that's what I had to do once. luckily my first printer came with 2 rods for just that reason. 100% been there

Re: filament jam / PTFE tube removal problems

Benjamin. Cut the PTFEjust above the black ring. Remove the Heat break from the other side of the finned part then push the remaining Ptfe tube into the finned part and is should come out easily.

Don't try pulling again because the teeth on the black ring will have dug into the Ptfe

Regards Joan

Re: filament jam / PTFE tube removal problems

or try a metal rod (about 1.75mm) and just push, I think that's what I had to do once. luckily my first printer came with 2 rods for just that reason. 100% been there

I had a jam with ABS, and the filament was in there tight and would not budge. I removed the PTFE tube and then heated it with a heat gun. I pushed it out with a small Allen wrench.

Re: filament jam / PTFE tube removal problems

Benjamin. Cut the PTFEjust above the black ring. Remove the Heat break from the other side of the finned part then push the remaining Ptfe tube into the finned part and is should come out easily.

Don't try pulling again because the teeth on the black ring will have dug into the Ptfe

Regards Joan

What is the best way to remove the heat break?

Re: filament jam / PTFE tube removal problems

as you already have the heatblock off and the heatsink/heatbreak module on the desk,

protect the threads with a couple of layers if thin card,
grip the card, over the threads carefully with a pair of pliers. grip the heatsink in your hand, and carefully unscrew the heatsink from the heatbreak.

be careful not to twist the heatbreak in such a way as to bend it... the thin part is fragile!

the heatbreak should not be excessively tight

it should come apart like this..

you can see a grey film on the threads, this is heat sink paste that I added

if you could see the other screw threads, you would see that I have spread Coppaslip antisieze paste on them, to prevent them seizing upwith filament.

when I first heat the assembly after adding the coppaslip, I pot some tissue under the nozzle, to catch the first waste when I load filament, so that the anti sieze doesn't get onto the Pei

regards Joan

Re: filament jam / PTFE tube removal problems

take extra care with it. but at least you have it out of your hotend allready

Re: filament jam / PTFE tube removal problems

I think the heatbreak is winning this battle. Twisting left to loosen, right?

Re: filament jam / PTFE tube removal problems

I had a piece of filament stuck in the PTFE tube because I let the filament run out (don't do that). The PTFE tube seemed stuck in the heatsink, probably because the tube could not flex due to the rock-hard filament stuck in it. I didn't want to force the PTFE tube out for fear of breaking the collet. So put the heatsink in a vice and heated it with a heat gun, while pushing a 1.5mm allen key in through the bottom. Soon the filament that was stuck in the heatsink softened up, so the allen key could advance through it toward the PTFE tube. Eventually, it advanced far enough so that the cold filament was pushed up through the top of the PTFE tube far enough for me to grab it and pull it out. Once the filament was gone, the PTFE tube was soft enough so that I could grab it at the base with a pliers and wedge it out.

Moral of the story -- if the PTFE tube is stuck with filament in it, you have to get the filament out because the stuck, hard filament could prevent the PTFE tube from flexing enough to advance past the collet that is holding it in. Heat the extruder until the filament jam in the extruder melts enough so you can insert something in there (i.e. 1.5mm allen key) to push the filament out the top of the PTFE. Then you can remove the PTFE tube, or maybe you even won't have to. I destroyed my PTFE by first trying to remove it while the filament was still stuck in it. If I'd gotten the filament out first, the PTFE wouldn't have needed to be removed and hence wouldn't have been destroyed.

BTW I wouldn't recommend trying to remove the heatbreak to get to filament stuck in the PTFE tube. You need to melt the filament jam in the heatsink through an external heat source in order to reach the PTFE from the bottom, and the filament will melt when external heat is applied whether the heatbreak is installed or or not.

Re: filament jam / PTFE tube removal problems

also if you use something like a torch to heat the heat sink to get the heat break out you have to use care to to over heat the PTFE tube... if it chars it can release hydrofluoric acid https://en.wikipedia.org/wiki/Hydrofluoric_acid which is extremely nasty and dangerous stuff this is also the reason not to run a v6 type of extruder above 300c.

a similar fluro elastomer Viton was a wonder material (and still is a very useful product) used for O'Rings and there were some nasty accidents in the early 60s when it first started turning up in auto parts. amongst auto mechanics as one quick way to hold an exhaust manifold gasket to the block was to slide used o'rings over the studs for this reason mechanics got in the habit of stripping useful sized o'rings off of scrapped parts when replacing them and tossing them in a corner of their tool chest... if you did that with Viton and the exhaust flanges got hot enough those o'rings would slightly char and if they were touched the HF in the char would head straight for the finger bone that touched it and if not treated FAST you could not just loose the finger but die with calcium channel interruption to things like heart rhythm.

That wiki link above should be read by anyone that works around fluro elastomers where they could go over temp as in a runaway hot end.

Re: filament jam / PTFE tube removal problems

[...] if they were touched the HF in the char would head straight for the finger bone that touched it and if not treated FAST you could not just loose the finger but die with calcium channel interruption to things like heart rhythm.

That wiki link above should be read by anyone that works around fluro elastomers where they could go over temp as in a runaway hot end.
Well, that got dark quickly! Great info though, thanks. I think theirs a tendency to be a bit cavalier with handling some of these materials. Some hard-won wisdom from the past is worth remembering. Kind of makes the nano-particles the least of our worries!

Re: filament jam / PTFE tube removal problems

Bob I'm someone from another time where a visit to my village dentist as a young kid in the 50s would usually result in a capsule sample of mercury to play with. (it was fun to rub the Hg into a shiny penny (which back then was solid copper) to make it look a bit like a dime) so by modern standards I am not a safety preacher... I take what seem to me to be reasonable precautions... I also melted down lead wheel weights to cast my own bullets and it was just common sense to do so outside and stand upwind of the melting pot and not add scrap lead to an existing melt ( hidden moisture in scrap can cause a steam explosion if you do that ) I also used common sense and washed my hands after handling lead people have know since Roman times to take these sort of precautions. in my old age I use a positive pressure VOC filtered mask when dealing with many paints and things like Toluline (and acetone needs to be respected in regard to it s vapors.

But HF is something that is at another level even compared to the many chemicals found in my machine shop things like simple Benzine we used to use for cleaning parts for example.... I am lucky enough to have escaped serious repercussions from these things but I believe that he idiopathic Peripheral neuropathy that has dogged me for the last 25 years could be related to those exposures... So I do like to try to get youngsters to follow modern best practice and not just the "common sense" response I used for so many years