Print Quality - Gaps at beginning of outer skin



  • I've been trying to solve this problem for weeks and i'm at a loss with it. My extruder doesn't start laying down material until its 5mm into the outer skin layer but interestingly this problem doesn't appear on smaller printed parts (see images)

    ![1_1570344738137_20191006_074531.jpg](Uploading 100%) ![0_1570344738135_20191006_074526.jpg](Uploading 100%)
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    I'm slicing the model in Cura, the print shown is PLA printed at 200 Celsius with:

    • no retraction
    • no coasting
    • no outer wall wipe
    • Z seam aligned to sharpest corner
    • e3d titan aero on a cartesian machine
    • No pressure advance from the Duet
    • No fancy settings in Cura (like equalize filament flow, though i have tried it with no improvement)

    I've played with acceleration, jerk and speed in my Duet 2, settings are currently a conservative:

    Jerk: X 500, Y 500, E 1200 (mm/min)
    Accel: X 800, Y 800, E1200 (mm/min)
    Max speed: set high but in slicer i've printed between 40 and 90mm/s with travels between 90 and 160mm/s

    My extruder is calibrated but i've experimented with increased extrusion multipliers to the point of obvious over extrusion and the problem still persists.

    Like i say on smaller prints the problem is non existent, i get a near perfect Benchy print with 0.6mm retraction, 0.1 outer wall wipe and at jerk and acceleration 50% higher than what i've currently dialled back to.

    Can anyone make suggestions to what you think might be the cause of the problem?



  • Two settings you don't mention but are worth trying are to set combing to "no-skin" and the max comb distance with no retract to something like 10 or 20.



  • @nbGU said in Print Quality - Gaps at beginning of outer skin:

    no retraction

    why are you printing with no retractions?



  • I normally print with 0.4mm retraction on small prints and get great results. I tried no retraction to try to solve this problem.

    I switched to a default Cura profile today and my issue entirely went away, haven't gone through and figured out which setting was causing the problem yet though.


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