First (ever) dual extrusion - advice?

Discussion in 'Calibration, Help, and Troubleshooting' started by wfredette, Mar 12, 2016.

  1. wfredette

    wfredette Well-Known Member

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    Though my delta has two hotends, I've never tried dual extrusion with it. I just finished the traffic cone on my Big Box dual, using the experimental S3D profile created by Greg Holloway. I'm pretty happy with how close I got on the nozzle offset for a first go, but I noticed a lot of heaping of filament when the first nozzle was laying down infill on the first couple of layers. This had the second nozzle hitting little nubs of plastic and getting bumped around in a worrying way. I calibrated e-steps/mm for the T0 (I know there is a script to change e-steps with tool changes in the profile, but I left that commented out for now), and lowered the feed rate to 85%, but I wonder if there's something else I should be doing to minimize this problem. Is it just overextrusion? Also, I'd welcome any other feedback. Looking at this photo, it almost seems as though I have some Z-banding, but it's not as evident to the naked eye.
    [​IMG]
     
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  2. PsyVision

    PsyVision Moderator
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    Are your nozzles level with one another?
     
  3. wfredette

    wfredette Well-Known Member

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    They were as close as I could get them. I find the grub screw adjustment to be kind of wonky. Since T1 cleared the model on all layers after the first few, I think it was more a problem of the unevenness of the first layers' infill. I think this, too, because T0 was hitting as well. Am I correct in reducing the flowrate to try to tame that bumpy infill?
     
  4. Mike Kelly

    Mike Kelly Volunteer

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    Did you calibrate your extruder steps per mm for each nozzle? It's very important for dual printing that everything is very well calibrated and aligned.

    I don't fully understand what flow rate modifies but I think it has issues with retractions. Best to leave it at 100% and adjust the steps.
     
  5. wfredette

    wfredette Well-Known Member

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    Yep. I adjusted the e-steps. Good to know about flow rate, though. I'll leave it alone. Unfortunately the fan on my second extruder seems to have failed. So, no more dual extrusion until I get a replacement...
     
    Rob Heinzonly likes this.
  6. Rob Heinzonly

    Rob Heinzonly Well-Known Member

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    @wfredette I had similar problems with my dual Benchy this weekend (see post). I think it was caused by the secret-e3d-dual-purge-anti-ooze recipe. To be continued I think.
     

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