How to cold pull with Hemera?

Discussion in 'HotEnds & Extruders' started by Kuli, Nov 14, 2020.

  1. Kuli

    Kuli New Member

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    Had a nasty clog today, went to do a cold pull and found that the non-idler hobbed gear catches on the filament when trying to feed by hand/pull out. There doesn't seem to be a clean way to bypass the hobbed gears. I think the 3:1 gearing makes this worse as it's harder to overdrive the motor. Anyone got a good procedure for declogging with Hemera? I'd hate to have to disassemble the whole extruder everytime I get a clog.
     
  2. Marcus Mendenhall

    Marcus Mendenhall Active Member

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    I do a cold pull on my Hemera by just getting some filament feeding, then cooling to 160C or so and retracting 100 mm at 50 mm/s, while gently pulling the filament back with my hand so that the slightly melted end really clears the gears. In 20 kg of printing, I have only had one jam, and that was when I didn't pull with my hand, so the melted end stopped right in the middle of the gearing. I had to disassemble to fix that.
     
  3. mtngeek

    mtngeek Member

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    I just heat it up to +10C past what the filament was using, poke it with my handy probe that I got with my Ender 3, then push the next filament through for about 30mm until it comes out clean. It's worked for me when clearing PETG or TPU with PLA (that prefers much less heat, but it still pushes the hotter filaments out).
     

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