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Joel Telling's video on heat creep in the R2

Discussion in 'Troubleshooting' started by sgomes, Sep 6, 2017.

  1. sgomes

    sgomes Active Member

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    Joel's been testing a bunch of PLA and PLA-likes on the R2 and found the same that a bunch of us have run into: heat creep.

    I disagree with his assessment that the issue is the Robo plate in the front (it may contribute to the problem, but I doubt it's the biggest factor), but the video may nonetheless be a good catalyst to get Robo looking into this a bit more closely, and figure out a way of improving airflow to the hotend.

     
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  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    I have considered replacing the plate with an additional fan (on a snap-in rig).
    Never been enough of an issue to make me get motivated for it yet. Even with the plate in place and two hot extruders in there I have no issues with creep on the C2 :)
     
  3. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    Watched it also, I am in the process of designing a completely different setup that uses radial fans for parts cooling and a bigger fan for the Hexagon, if I don't scrap the Hexagon completely for a E3Dv6.

    I think a lot also has to do with excessive retraction. I remember reading a long time ago that E3D recommended never exceeding 3 mm (half the length of their v6 nozzle) when retracting.
     
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  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    You make that sort of mod and I am along for the ride. I would love to replace that with a dual-E3D setup.
     
  5. sgomes

    sgomes Active Member

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    I've always done 1mm retraction, and even when setting it to really low speeds, I was getting clogging with ColorFabb PLA/PHA. Only disabling it altogether worked. That, or keeping the door open to reduce heat.
     
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  6. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    I think he is on to something and I know that the printable shroud takes babysteps to try and resolve this. I think you need to scrap the whole back end and use a much bigger fan to keep the cold zone separate from the hot zone. I never liked the design of the Hexagon and swapped my R1 to an E3Dv6 very early on. The real advantage to the E3D is the design of the heatbreak. It is well thought out and really separates the two zones very well
     
  7. jwmueller

    jwmueller Active Member

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    Hmm, I have held my hand below while it is heating up and I can feel the airflow. An easy thing to try would be reversing the fan maybe, not sure if my PETG prints would like that. I have done some 36-hour PETG prints without any issue, I am using zhop and retractions. Cooling fans were off.

    MakerGeeks PLA I was in the 230-235 range without any issues, ran a few benchy prints. Other PLA I was down in the 190 range.

    Here is my Prusa Moon city, I will run one for fun on the R2 in a MakerGeeks PLA. I would think with the Robo plate in place there is a bit of a vortex inside the extruder area. I am currently running a Palette+ print on the R2, so it might be tomorrow before I can play around. The video has me curious for sure, does he have a link to the coin he is printing?

    (One thing I need to fix is that my Robo plate is touching the hexagon)
     
  8. Geof

    Geof Volunteer Moderator
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    you need the fan blowing on the coldend. I personally think its a combo issue that @WheresWaldo likely has the best solution to ATM. The small cheap underrated cold end fan combined with a restricted area then you slap a puny extruder like the direct drive on many machines that are picky (R2 included) and your just in trouble. We were all (including Robo) use to the R1 series with the monster greg wade that just shoves filament through...R2...well its a little baby at the moment :D.

    disclaimer: I dont have a R2 this is opinions based off what I'm seeing and feedback from working closely with a few R2 owners. Get to hackin gents :D
     
  9. supercazzola

    supercazzola Active Member

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    I think this heat creep is what is causing me issues with my PETG prints. The first 50 mm or so print well, but then the rest fails - like extrusion issues. Tried using a ball bearing spool holder. No difference. Took the metal Robo cover off and got it to make it to 70mm height without issue. But still failing.


    Sent from my iPad using Tapatalk Pro
     
  10. Kilrah

    Kilrah Well-Known Member

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    I still haven't had a heat creep issue, only clogs due to a shitty copper filament.

    This looks more like a problem with the stepper getting hot, and as such softening the filament where it's pinched/driven. Again only had that issue once with said shitty filament that becomes soft as butter at 50-60° already.
     
  11. supercazzola

    supercazzola Active Member

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    I will try another PETG product then. This was Hatchbox, which I have had great luck with their PLA. Can you recommend a brand and exact color PETG roll you have had success with? thanks
     
  12. jwmueller

    jwmueller Active Member

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    I am not a fan of their PETG, but I have not tried it in a few years. I can send you a sample of MakerGeeks PETG if you want, and have some ColorFabb XT that is not enough for me to use. If I remember right the Hatchbox was a much lower temp PETG, while MG/ColorFabb I am in the 260 to 245 region. I have run a few 36+ hour PETG prints on the R2, ran a few Palette+ tests that ended up at 26hrs and had 72 splices with no issues. For about a week I was running 10hr prints 2x/day.

    @Kilrah I did put a heatshink on my extruder stepper, and now with long PLA prints it has been much better. I almost want a fan on it, but hopefully Robo can tune it via the firmware. I was getting jams where the PLA was coming off the gears at an angle and would turn into an S going down to the extruder. Putting my finger on the extruder gear was hot enough to only hold for a few seconds. I do not like that the stepper is mounted to plastic.

    Important - if you add a heatsink, watch your clearances so it does not hit the gantry.
     
  13. Geof

    Geof Volunteer Moderator
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    I would agree on the heatcreep, you also have to remember the hexagon hotend is unforgiving. If you combine those two things then yes...issues. The small fan that blows on the cold end needs to be on at all times and directed to the cold end (look at how E3D does it) I'd be interested to see someone put a 30x30x10mm fan in place with a small duct on it to direct airflow and see what improvements (if any) happen.

    My 2nd thought to that would be to get and try a better hobb gear and rule out the possibility that there is to much pressure and not enough grip and drive :D
     
  14. jwmueller

    jwmueller Active Member

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    I just threw together a fan shroud that plugs into the spare extruder spot, will post the files once I like it. Just something to redirect all the flow over the fins.
     
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  15. Geof

    Geof Volunteer Moderator
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    Can't wait to hear your results
     
  16. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    It is the design of the heatbreak where the Hexagon fails. It is simply a tube with no thermal break from hot zone to cold zone. That is why the E3D is such a much better design,
    [​IMG]

    That section between the threaded parts is a thermal break and actually prevents heat from creeping up the hotend. That and a better fan could eliminate all the heat creep issues with the R2. Since this is a premium printer is should have had a better hotend. My guess (based on nothing concrete) is that Robo can use the Hexagon royalty free as they are listed as a distributor on the Hexagon Wiki page.

    I will be ordering an E3Dv6 this weekend to replace the Hexagon.
     
  17. Geof

    Geof Volunteer Moderator
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    Indeed. I am not a fan of the hexagon, its just cheap (and not really considering the price of "good ones"). Excited to see your upgrade Waldo.
     
  18. jwmueller

    jwmueller Active Member

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    20170913_105356.jpg 20170913_105425.jpg 20170913_105409.jpg

    Need to make some minor changes, but I can already feel the difference on the far side of the hexagon.
     
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  19. Geof

    Geof Volunteer Moderator
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    amazing what happens when you aim that fan right ;) :D good job man looks good.
     
  20. Hanover

    Hanover Member

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    Hmmm...I'm starting to get buyers remorse. If you had the opportunity to trade your R2 in for two MK2s's, would you?
     

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