E3d v6 keeps clogging

Discussion in 'E3D-v6 and Lite6' started by Patryk3463, Aug 31, 2017.

  1. Patryk3463

    Patryk3463 Member

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    Hello everyone. Im quite new to the 3d printing and I'm not too sure how to fix few problems. What im struggling with is mk2s keeps clogging with original fillament and extruder motor skills steps leading into failures. It happened a few times before but usually all I do is set temperature to 280 degrees and force the clog out which has worked, but now my 8h print has failed at 96% due to a clog which really annoyed me. So I have taken it apart and i found the clog not in the nozzle, not in the cold side but rather in that tube between the two. So I have heated it up and pushed out the clog. I dont want to put everything together again just to have it clog again. I thought before I do that ill ask someone with more experience.

    I have tried to clean out the tube completely but it seems solid. It looks like the tube wasn't drilled all the way through ? And when I push fillament through it creates small resistance. Could that be there intentionally ? To stop molten plastic climb up around fillament? Or coild it still be plastic ? 20170830_223055.jpg 20170831_041410.jpg 20170830_223801.jpg 20170830_223423.jpg 20170830_223333.jpg 20170830_223055.jpg 20170831_041410.jpg
     
  2. Old_Tafr

    Old_Tafr Well-Known Member

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    Sounds like the heatbreak tube is getting too hot. Maybe there isn't enough cooling, so fan speed too low? or not directed onto the heat sink? I found that the blue shroud could be fitted either way up, but that it isn't symetrical, so worth having a look at that.

    The build instructions at some stage do say that the shroud can be fitted either way up, but fitting it the wrong way (ok which way is "wrong"?) has two effects...

    A. Less air is directed onto the fins of the heat sink.

    B. The shroud can touch the hot end and melt. Obviously depends on the arrangement of the whole assembly, printer type etc.

    On my BigBox the top of the fan is exactly level with the top (largest) fin of the heat sink.

    I did put a note in the build instruction about this, just checking the link.
     
  3. Patryk3463

    Patryk3463 Member

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    The printer I have (prusa i3 mk2s) doesnt have the original blue shroud that comes with original e3d v6, instead the cold end is fitted into an enclosed carriage with a fan blowing onto the fins. I did think this would be the issue too but I've seen online that if I touch it with fingers after a longer print and its cold, that's not the problem. I have had it on at 280 degrees for 10 minutes and the bottom of the fins was not hot but rather a little warm and the rest were cold. Should they all be cold to touch ?
     
  4. Old_Tafr

    Old_Tafr Well-Known Member

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    I guess you have to think how molten plastic could get into the heat break tube.

    A. Heat from the hotend rising up through the heat break and simply softening the filament until sufficient build up causes a problem.
    B. Far too much retraction pulling molten filament into the heat break.
    C. Some kind of back pressure (clutching at straws here but maybe filament that has absorbed moisture {hygroscopic} and the heat boils the water and the force has to go somewhere)
    D. Filament getting scraped off inside the heat break or heat sink then building up and melting

    Any of the above happening or made worse by the fan running too slow or not cooling the heat sink and heat break sufficiently possibly as not properly directed at the heat sink

    I guess you can't have too much cooling on the heat sink (ish), E3D have somewhere a note saying how hot or cool the heat sink should be but I can't remember where I saw this, I suspect it was cool to the touch.

    Do you have a way of accurately monitoring the temperature of the hot end? Maybe it gets hotter than you think.
     
  5. Patryk3463

    Patryk3463 Member

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    Unfortunately I don't have any equipment to measure the temperature at this point in time. I will go to university and ask if I can borrow a thermal camera or a laser thermometer so I can check if it does get too hot. What temperature would be classified as too hot ?

    The settings I use are default prusa i3 ones so 0.8mm retraction. I could lower it haven't tried it yet.
    - moisture is a high possibility, is there a way to check this ? Now thinking about it, it hasn't jammed once with a brand new filament from rigid.ink. but that might not be a good example of possible moisture as rigid ink recommends 180c and original at 210c. Different pla properties.

    What I have done today was clean the heat break so it's smooth inside but upon reassembly I broke a fan cable and it was impossible to re solder onto the pcb( ripped entire connection part out solder wont stick).

    Another thing I realised today was that the heatbreak was loose, it wasn't tight at all when I unscrewed it. No tools were needed maybe that was one of the issues.

    Either way, I shall wait for the replacement fan and I shall update this post in 2-3 days. Is there any sort of stress test ? Something to check if it jams because previously it would happen once a week and I don't want to wait a week to find out it jams again.
     
  6. Old_Tafr

    Old_Tafr Well-Known Member

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    Sounds to me like the lack of tightness is most likely the problem. The BigBox assembly instructions point at the V6 assembly of heater block, heat break and heat sink. This includes how far to screw in the various parts, how tight to tighten and the procedure to heat the assembly and then tighten. The biggest danger is tightening the heat break too much and snapping it in half.
     
  7. Patryk3463

    Patryk3463 Member

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    I have had a look at the bigbox assembly of the v6 hotend and I have noticed at the first part it says to apply thermal paste. The original hotend had just a shiny thread with 0 paste, I do have spare arctic silver that I will apply. During last assembly i broke a fan so I will need to wait for 2-3 days in order to test if everything is ok. Thank you for that, I shall update when i have the printer fully assembled. :)
     
  8. Old_Tafr

    Old_Tafr Well-Known Member

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    V6 kits usually come with a little sachet of thermal paste, my fans on the BigBox don't have connectors as I never retro fitted them, but there are a number of posts about adding them, and I think later E3D ones now come with connectors, makes removing the hotend so much easier.

    There should be a note on the WiKi for your Prusa (another post only a few days ago had a link) and the notes on converting to a V6 which should included the adding of thermal paste and the tightening torque and the re-tightening when heated.
     
  9. Patryk3463

    Patryk3463 Member

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    I have received a new fan, put the 3d printer together with a bit of thermal paste between the heat break and the heat sink. Then I tightened all the parts of the heat block and so far I have completed 5h print with not a single clog. Today I shall try a longer print and see if it clogs this time. But so far thermal paste and tightening the block helped. Thanks
     

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