Nozzel Issue

Discussion in 'General' started by Miasmictruth, Jan 13, 2016.

  1. Miasmictruth

    Miasmictruth Well-Known Member

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    I ordered some carbon fiber filament and hardend nozzels for when I get my big box, but I already have a low end printer.

    To make a long story short the hardend nozzel is the same size and thred so I figured I would give carbon fiber a try.

    I layed down the first layer for a single walled print, looked like it would be fine but then it started under extruding, I don't think it was skipping steps it didn't hear the characteristic thump when it slips on the filament but maybe. The tried regular PLA and that is struggling too.

    I took out the nozzel found a metal flake that feel off the threads, thinking that may have been blocking the flow I put it back together but I still same results.

    I can push the filiment by hand just fine, can it be the hardend nozzel having differnt characteristics or something else? I can't even print regular PLA now, going to take the whole extruder part and put the old nozzel on when I get home.
     
  2. mike01hu

    mike01hu Well-Known Member

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    I seem to recall a similar conversation but can't remember where. What I remember is that the problem seemed to come from the hob bolt and tension in that the hob teeth were not sharp enough or the tension not high enough. It has to be remembered that filled filaments are not as viscous in the melt as non-filled filaments and do require firm and constant pressure to maintain the flow. Also, carbon filled filament is much harder than other filaments, so it is more difficult for the hob bolt to grip and feed it to the nozzle, hence the need for better tension. Feeding by hand does not help defining the problem but observing the hob during feed, if possible, may show it. Also, the carbon fibres can gather and restrict flow but this is more of an issue with narrow nozzles; my guess is that 0.4mm is about a small as one should go but until I get my kit and filament I can't be sure. It's going to be an important issue for me, so any help here will be appreciated,

    Mike
     
  3. Miasmictruth

    Miasmictruth Well-Known Member

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    Thanks for the reply, I thought it might be something like that for carbon fiber. The part that got me is when I went to switch back to PLA I couldn't print that either.

    I think the heat break is the issue, it seems to have degraded to the point I can't get filament through very easy. When I yore everything apart it wasn't looking too good.

    I think it was already degrading and the carbon fiber just finished it off. I ordered a new one so we will see.

    The machine was rather cheap and I found an issue in the mechincs of the extruder. I knew about it but when I took it apart it seemed worse (has a couple hundred hours on it at least) I am going to try to get a guy at work to mill out the troubling issue so I can resolve it once and for all.

    Can't wait for the big box so I can work with some quality parts.
     
  4. mike01hu

    mike01hu Well-Known Member

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    Good luck!

    Mike
     

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