Blockage Problems.

Discussion in 'Calibration, Help, and Troubleshooting' started by Syko_Symatic, Jan 5, 2017.

  1. Syko_Symatic

    Syko_Symatic Well-Known Member

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    I have suffered several blockages over the past few weeks. Generally the filament stops being extruded for whatever reason and ends up blocking the nozzle. This is not an issue, I have invested in a huge box of acupuncture needles and so can clear that without issue.

    The problem is that when the blockage occurs the filament above the nozzle (a few mm above at least) splays out and then can not be removed without taking the hot end apart as it will not come out the top of the heat sink! All I can think is that the filament is getting too soft too high up?

    Edit: Maybe it is a speed problem on the first layer? I have it at 40%, perhaps that is too slow as I have noticed the material (both Edge and PLA) have concertinaed at times.

    Am I correct in my assumption? Is there a solution? Is there another reason.

    Here is the set up:
    BIGBOX DUAL (Dual Titan @Chase.Wichert design.)
    0.40mm Nozzle
    40mm/s Print Speed (40% first layer)
    Edge (Black)
    Bed: 100°C (First layer) dropping to 90°
    Head: 240°
    Fan on 50% after first layer.
     
    #1 Syko_Symatic, Jan 5, 2017
    Last edited: Jan 5, 2017
  2. Ephemeris

    Ephemeris Well-Known Member

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    I doubt low speed is an issue. I typically run layer 1 at 20% speed. Dose the stepper start clicking during layer 1? (If so, post a picture of what layer 1 looks like.) Some batches of filament are jam-o-matic due to impurities or whatnot, so maybe try another spool for awhile and see if the problem persists. As for not being able to get the filament out, I'd like to see a picture of that too.
     
  3. Syko_Symatic

    Syko_Symatic Well-Known Member

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    I will pull the offending hot end and filament out tonight and take some pictures. It does not click generally it just get blocked and the hobb starts eating away at the filament line in the Titan. I have a brand spanking new set of metal pieces for the hot end so I will put those together and get them on the machine then pull the old one apart. I will be stripping it down tomorrow to replace the lead screws so not much chance to test print anything until Saturday.
     
  4. GrodanB

    GrodanB Well-Known Member

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    Check your retraction settings. I use 1.1mm or I get blockage.
     
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  5. Syko_Symatic

    Syko_Symatic Well-Known Member

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    Mine is currently 0.6mm. Do you mean less and you get a blockage or more?
     
  6. GrodanB

    GrodanB Well-Known Member

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    No, when I have more I get blockage. Then it seems like it get drawn up to high and get to cold

    0.6 should not be the reason then
     
  7. mike01hu

    mike01hu Well-Known Member

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    Check the length of the PTFE tube and that the Bowden lock is tight as it seems that you may be drawing warm filament into a void between the hotend and the heat break rod; what happens then is that the next feed by the extruder forces the filament to expand into that gap and cause the jam. The PTFE tube must reach the bottom in the heat break and stay there. I would make a fresh cut of the tube to ensure it is square to the end.
     
  8. Syko_Symatic

    Syko_Symatic Well-Known Member

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    I don't have a bowden setup. I am running dual titans. I think that may be the issue though! Looking closely at the hobs in the titans and reading around here it seems as if I may have some of the dodgy hobs! The filament seems to be trying to work its was off the teeth all the time leading to inconsistent printing. May have to get them replaced and see if that's solves some of my issues.
     
  9. Spoon Unit

    Spoon Unit Well-Known Member

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    You do have a bowden setup; we all do in a small way. I think @mike01hu is referring to the collet at the top of the v6 heatsink, into which you feed the PTFE tube down from the Titan. Effectively, this is just a very short run bowden setup.
     
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  10. Syko_Symatic

    Syko_Symatic Well-Known Member

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    So.... The PTFE..... Yeah.... Uh...... Should really have out that in there when I changed the hot end a while back! Whoops! That's probably my issue! Good spot!
     

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