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Unresolved PETG Buckling and Clog

Discussion in 'Troubleshooting' started by sesl, Dec 5, 2015.

  1. sesl

    sesl New Member

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    So I just got my R1+ off Amazon a couple weeks ago and have pretty much been printing non stop with Hatchbox ABS and eSun PETG. I switched to the PETG today to print off a Pi case for an Octopi setup and was able to print off half the case without any issues. However, when I loaded the second half, it kept failing in the middle of the print and just end up air printing. When I went to unload the filament, I found that the filament itself buckled and kinda mangled up just below the hobbed bolt.

    I got rid of the jam, reloaded, and tried again. I tried this 3 times and kept doing the same thing. I had done an estep calibration the moment I first opened it up so I tried even reverting back to the factory default of 723 (calibration came out to about 789) but same thing kept happening.

    I figured there must be a clog so I took apart the extruder and burned out the nozzle with a lighter. When I tried to unscrew the heat break, it stripped half way out of the hotend and won't go back in so now I'm trying to hopefully get a replacement from Robo.

    Any ideas on what could be causing the buckling? Maybe a clog causing the buckling or vice versa? Does PETG need to be oiled?
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    PETG does not need oiling, but I just leave the damn thing on for all filaments these days.
    Sounds more like incorrect temperature. If you are borderline too cold for that filament it would want to periodically bind up (like a clog) which is what you are describing. Most filament will absorb moisture and become 'wet'. Once that happens the sweet spot print setting can (and often will) shift a little.

    Being too hot adds it own set of problems, but perhaps you are just a little cool now.
     
  3. sesl

    sesl New Member

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    Yeah, that definitely makes sense. I'll have to try that whenever I get my replacement. I already had to raise the temps up to 240 because I was having issues with adhesion since the last time I used it. I wonder if that'll help with all the stringy mess that I get whenever I use the stuff as well.

    Thanks for the quick reply!
     
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Well, heh, we'll see. Stringing is 'usually' a symptom of a too hot print. However, that is really only certain for ABS and PLA. Other filaments behave differently. You can't apply that rule to most nylons or nylon derivatives for example... I am not sure on PETG, I haven't used it. I have used PETT and it has a very narrow band for proper extrusion. There is a fine line between too cold and a stringy mess with it.
     
  5. Caleb Cangelosi

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    @sesl, can you tell me how you did the estep calibration? Mike Kelly said that is important. I just got my machine, and it has been printing perfectly as far as I can tell, so I don't know that I need to recalibrate, but perhaps I should for even better prints? One video I saw on it was a bit over my head... Also, in your experience, how does the petg compare to pla in terms of print quality, strength, etc.? I've got some I'm looking forward to trying.


    Sent from my iPad using Tapatalk
     
    #5 Caleb Cangelosi, Dec 5, 2015
    Last edited by a moderator: Dec 5, 2015
  6. Nathanfish

    Nathanfish Active Member

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    I had the same problem with PETG. Look into putting a PTFE tube right after the hob bolt so the PETG can't buckle. I did this on both of my machines and haven't had a single problem with it since on either one.

    Are you using Simplify3D?
     
  7. sesl

    sesl New Member

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    Honestly, "stringy mess" is exaggerating. It get some extremely tiny strings when I print and usually only on the first couple layers but doesn't affect print quality otherwise. I've read that the material itself has a tendency to do that despite retraction but I'll play around with it more.


    @Caleb Cangelosi Here's the two videos I followed for my estep calibration. I watched and kept pausing/rewinding to catch exactly what he was saying or what he was doing. Tom's video shows you how to do it via a terminal but I felt like the second video was easier to follow as far as the exact math that needed to be done although he uses a LCD controller to make his changes (it's pretty straightforward regardless)



    As far as print quality, it's probably about the same despite the little strings I get from time to time. Strength wise I would say it's strong probably about as strong as ABS but more flexible as well. Just be sure to use something like hairspray on the bed because I could never get it to stick to the supplied glue stick.

    @Nathanfish Thanks! I was actually wondering about that and just pulled the trigger on the PTFE tube you posted. I'm still using Cura but I'm really tempted to get Simplify3D. Is there a specific setting that helps with that as well?
     
  8. Nathanfish

    Nathanfish Active Member

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    Glad to help. You'll need to shave down the OD on one end of the tube so it fits snug and you'll only need around 1/2". You can play with the retraction settings in simplify but PETG is pretty stringy material.
     
  9. Rene

    Rene New Member

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    Hi , did you fix the problem using PETG on your ROBO R1 if so can you tell me and what setting you are using or pictures . A friend lend me his printer for a few months well he over seas . I want to use PETG Thanks
     

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