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MK3S (!!!) ptfe jamfor the second time!  

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eyals
(@eyals)
Active Member
MK3S (!!!) ptfe jamfor the second time!

Hi,

I upgraded my MK3 to MK3S, and on the second print the filament was jammed at the PTFE entrance - with no ability to pull/push it, as it is swollen.

I disassembled & reassembled the extruder replacing the PTFE with the spare PFTE that was in the upgrade kit (I heated up the extruder and pulled the PFTE tube, while destroying it...)

Now after the first print, it happened again. you can see the problem in the youtube I found on the net (seems like I'm not alone with this problem...).

Before spending more time on replacing the PTFE tube, does anyone has a clue why it happens? 

 

Thanks,

EyalS

This topic was modified 3 years ago by eyals
Posted : 02/06/2019 2:29 pm
Peter M
(@peter-m)
Noble Member
RE: MK3S (!!!) ptfe jamfor the second time!

More info could help, otherwise search on the forum, you find similair topics, what you have tested/repared, tell us.

temps, filamant, etc

We do not have a glass bowl that tell us everything........

Posted : 02/06/2019 8:11 pm
eyals
(@eyals)
Active Member
Topic starter answered:
RE: MK3S (!!!) ptfe jamfor the second time!

It's standard prusament PLA. 215 deg. print completed, but on the last layers nothing was extruded...

Posted : 02/06/2019 8:48 pm
da4throux
(@da4throux)
Active Member
RE: MK3S (!!!) ptfe jamfor the second time!

I feel like I have the same issue - so I will not create a new thread but piggy back on yours.

I went for the MK3 to MMU2 upgrade, MMU2 being a bit too hard to calibrate for me, I unplugged it, and thought I would first get use to the MK3S (as it is part of the upgrade).

Like you printing PLA - 215 degree - White Vanilla Prusament, and getting PTFE clogged for the second time ... (just ordered new ones ...)

I saw that Youtube video mentioning that the PTFE has been reworked for the MMU2, and it might create problems: and they suggested increasing temperature (but it was not for PLA...). So that might be link to that.

I was hoping to find a troubleshooting page dedicated to that, but so far I found how to punctually solve the clogging, not really about to re-calibrate / special check to do, in order to not have them anymore.

- dismantle PTFE: https://manual.prusa3d.com/Guide/How+to+replace+PTFE+tube+on+the+MK3S-MK2.5S-MMU2S/1418

If I find anything more, I'll post it here.

Posted : 03/06/2019 8:24 am
da4throux
(@da4throux)
Active Member
RE: MK3S (!!!) ptfe jamfor the second time!

Just found this thread: https://www.reddit.com/r/prusa3d/comments/a8zalh/jam_in_ptfe_tube_how_can_i_make_sure_this_never/

They link it to retraction, but it's not exactly the same problem. In my case it happens during print, but in that case it's more when unloading filament. However the root cause might be similar.

I will not be able to test anything until I receive new PTFE tubes though 😐 

Posted : 03/06/2019 11:35 pm
eyals
(@eyals)
Active Member
Topic starter answered:
RE: MK3S (!!!) ptfe jamfor the second time!

I tried pulling the filament out by heating the extruder to 250 deg and pulling it with sharp tweezers, but with no success.

A friend suggested to heat the extruder to 290 deg, and I was able to pull out the filament without ruining the PTFE...

Was managed to print two models since... @damien-r3 I suggest you try it also.

Posted : 04/06/2019 1:53 pm
Malacoda
(@malacoda)
New Member
RE: MK3S (!!!) ptfe jamfor the second time!

I suffered a similar problem. For me it was because I had constructed the Lack enclosure, and during a print with PLA or PETG, it would get too hot and cause PTFE blockages.

I've now installed two computer fans into the table and print with the doors ajar to keep the temperature low.

Posted : 05/06/2019 7:07 am
HeroSteve
(@herosteve)
New Member
RE: MK3S (!!!) ptfe jamfor the second time!

Hi,

i have a similar Problem. When I try to print with 0.1mm Detail PLA Settings, the Print gets stuck. Klicken Tasche the filament can’t be pushed anymore... usually unload, cutting off the first few centimetres of the filament and reloading helps.

yesterday the filament broke while uploading... can’t reach it with tools or push it through at 260 or 290 degrees...

any suggestions?

also... I looked for the price of the ptfe tube, but couldn’t find it in the Prusament shop...

Posted : 05/06/2019 9:49 am
eyals
(@eyals)
Active Member
Topic starter answered:
RE: MK3S (!!!) ptfe jamfor the second time!
Posted by: Malacoda

I suffered a similar problem. For me it was because I had constructed the Lack enclosure, and during a print with PLA or PETG, it would get too hot and cause PTFE blockages.

I've now installed two computer fans into the table and print with the doors ajar to keep the temperature low.

Thanks!, Just got an answer from Prusa support. It's exactly what you say. and I think you are right. I'm printing now with PETG, and the extruder motor is HOT!.
But than, I thought one of the reasons to build an enclosure would be to prevent particles from flying around the room. Adding fans will get all particles out...

 

Posted : 06/06/2019 10:18 pm
eyals
(@eyals)
Active Member
Topic starter answered:
RE: MK3S (!!!) ptfe jamfor the second time!
Posted by: HeroSteve

Hi,

i have a similar Problem. When I try to print with 0.1mm Detail PLA Settings, the Print gets stuck. Klicken Tasche the filament can’t be pushed anymore... usually unload, cutting off the first few centimetres of the filament and reloading helps.

yesterday the filament broke while uploading... can’t reach it with tools or push it through at 260 or 290 degrees...

any suggestions?

also... I looked for the price of the ptfe tube, but couldn’t find it in the Prusament shop...

Take a look at the link posted by damien-r3 - How to replace PTFE tube on the MK3S ( https://manual.prusa3d.com/Guide/How+to+replace+PTFE+tube+on+the+MK3S-MK2.5S-MMU2S/1418 )

Oddly, the spare parts menu in Prusa shop site, will only appear if you will login to the site.

The PTFE tube for MK3S can be found at: https://shop.prusa3d.com/en/spare-parts/929-ptfe-mk3smk25smmu2s-hotend.html

It costs, 0.69$

Posted : 06/06/2019 10:24 pm
Nick-i3mk3s
(@nick-i3mk3s)
Eminent Member
RE: MK3S (!!!) ptfe jamfor the second time!

Hi all,

I have the same problem, filament keeps jamming just below/above the PTFE tube and then getting stuck. It seems to happen with any layer thickness. I've ordered a spare PTFE tube from Ebay ( https://www.ebay.com/itm/PTFE-Tube-ID-2mm-OD-4mm-for-1-75-Filament-Makerbot-Prusa-Mendel-3D-Printer/161868367103 ).

Are they suggesting that the printer should be in a sufficiently cool room to prevent the filament from deforming?

Posted : 07/06/2019 11:24 am
Peter M
(@peter-m)
Noble Member
RE: MK3S (!!!) ptfe jamfor the second time!

Enclosure is for abs printing, so it does not warp.

On thingiverse you can find a extruder cooler, this is very good, it cools the extruder (also on this forum), so no heat moves to the filament.

A extra cooler to blow in the enclosure, for pla printing only, and for the summer.(you cools try this with a table fan and pla).

i have done both because of filament getting stuck. I have the mk3 (no S).

I also change the heatbreake to the normal e3d heatbreak, if this one is needed i do not know.

But what is very important, rebuild your, heatbrake, tube, nozzle, so you have 100% build without gaps, see this forum and youtube movies on how to.

Last i did also, after this i am printing a lot, and no problems.

Posted : 09/06/2019 3:21 pm
--
 --
(@)
Illustrious Member
RE: MK3S (!!!) ptfe jamfor the second time!

To all of you suffering this filament meltdown with jams in the PTFE tube.  Can I get some survey answers?

Printer: MK3 / MK3S / MK3 MMU / MK3S MMU

Material being printed: PLA / PETG/ ABS / NYLON

Nozzle Temp: 210 / 230 /250 /270 /290+ (pick closest)

Enclosure: Y/N 

IR temp of extruder motor case:  55c / 65c / 75c / 85c+   (if possible)

Ambient air temp around printer:  25c / 30c / 35c / 40c / 45c+

Thank you in advance ...

 

This post was modified 3 years ago by --
Posted : 09/06/2019 7:30 pm
da4throux
(@da4throux)
Active Member
RE: MK3S (!!!) ptfe jamfor the second time!

I did the same print that clogged by PTFE tube today, after replacing the PTFE tube with a new one (actually an old from my MK3 before the MK3S upgrade, it had to be cut because it was too long, and also had to make the opening wider on its upper side).

Still printing with PLA at 215, I just left the printer outside its closed fanless Ikea enclosure, used another a grey prusament (instead of white) and it has been working fine for a few hours now 😀 .

So it could have been: my original hardware mounting or calibration, the other filament (I'll try again later on), its position in the enclosure (I'll try again later, summer is coming anyway).

Posted : 09/06/2019 7:58 pm
Nick-i3mk3s
(@nick-i3mk3s)
Eminent Member
RE: MK3S (!!!) ptfe jamfor the second time!

Tim, are my survey answers:

Printer: MK3S

Material being printed: PLA

Nozzle Temp: 210 (closest, actually 215)

Enclosure: N

IR temp of extruder motor case: unknown

Ambient air temp around printer: 30c

Posted : 09/06/2019 8:49 pm
kenryan
(@kenryan)
Active Member
RE: MK3S (!!!) ptfe jamfor the second time!

I got my mk3s upgrade kit about a month ago, just tonight started putting it together.

When it came time to replace the PTFE tube I looked at it and thought "huh, this looks kinda small".  Measured it and the original with calipers - indeed, my original PTFE tube has a 2.23mm inside diameter, the ones in the upgrade kit are 1.63mm inside diameter.  Old one is larger than it should have been, new one is substantially smaller!  I tried several filaments, the silver Prusa filament that came with my original kit could be pushed into the tube with some force, *none* of my other filaments could even come close.  

This was barely 10 minutes ago, so I haven't contacted support yet, but I certainly am going to. 🙂

My point is, check that your new tube isn't overly restricting the filament movement!

ken

Posted : 10/06/2019 12:08 am
--
 --
(@)
Illustrious Member
RE: MK3S (!!!) ptfe jamfor the second time!

Ken - can you post up a photo of your "new" PTFE with a mm scale nearby.  Documentation of the small PTFE might be good to share. If you don't have a good scale (ruler), a few segments of 1.75mm filament will help.

Posted : 10/06/2019 2:19 am
Nigel
(@nigel)
Honorable Member
RE: MK3S (!!!) ptfe jamfor the second time!

I have a small spool of PTFE tube. Across my other 1.75mm filament printers, some Bowden.  I can cut it accurately due to a 3D printed jig. Look it up. PTFE tube is available very cheaply. On Amazon and elsewhere. 

This post was modified 3 years ago by Nigel

Nigel
Life is keeping interested and excited by knowledge and new things.

Posted : 10/06/2019 3:39 am
Flaviu
(@flaviu)
Estimable Member
RE: MK3S (!!!) ptfe jamfor the second time!

If you are not planning on using the MMU2(s) I would suggest everyone to install the stock e3d heatbreak instead of the prusa one.

Posted : 10/06/2019 7:55 am
eyals
(@eyals)
Active Member
Topic starter answered:
RE: MK3S (!!!) ptfe jamfor the second time!

Seems like it’s a major problem when using PLA on MK3S with the current extruder design.

The extruder motor gets a lot of heat, which makes the PLA melt before entering the PTFE tube - hence causing the jam.

You can see that people made several designs to cool down the motor, or even replaced the whole design:

https://www.prusaprinters.org/prints/3477-cooling-extruder-motor-system

https://www.prusaprinters.org/prints/3091-geared-mk3s-extruder

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

It seems like a new issue with MK3S that did not appear in MK3... 

I hope we will get an official response/solution from prusa....

 

Posted : 25/06/2019 5:26 am
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