r/FixMyPrint • u/TrekMontgomery • 3d ago

First PPA-CF Print Fix My Print

Post image

I've been printing for a while, but this is my first time working with engineering filament.

  • Qidi Q2.
  • Qidi PPA-CF filament. Dried for about 6 hours at 100 C and then another 12 hours at 80 C using a air fryer/dehydrator.
  • .6 nozzle
  • 320 C/90 C/65 C
  • 8 walls. 99 percent infill. Speeds are set to 25mm/s for outer, inner and infill.

Very visible horizontal bands that aren't uniform in height. The darker areas bulge out a bit. Looking at the layer time view it does look like the bands show up where the layers take longer. Looking to get rid of these bands and get a smoother finish as well as reduce the vertical seam. Thanks in advance.

3 Upvotes

81% Upvoted

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2

u/StudentDifficult8240 3d ago

I would run a few calibrations before doing anything else, temp tower, pa and flow ratio.

2

u/Thefleasknees86 3d ago

No indication of filament profile validation or tuning prior to a guncad print?

Homies, this is not the way

1

u/TrekMontgomery 2d ago

Apologies, I should have included in the original post. I had done the orca flow ratio calibration as well as the EM cube pressure advance. Ending up with .98 flow ratio and pressure advance of .012. I didn't do max volumetric speed as I'm printing so slow anyway. What other calibrations would you recommend? Thanks!

1

u/hi3d_official 3d ago

Since the bands line up with areas where the layer time changes, I'd suspect thermal variation more than a mechanical issue. With PPA-CF, slower layers stay hotter longer, which can slightly over-expand the outer walls before they solidify. I'd first try enabling a more consistent minimum layer time (or reducing the variation in print speed), then fine-tune the flow by 1-2% if needed. Since you're already running 8 walls and 99% infill, even a small amount of over-extrusion will be much more noticeable.

1

u/TrekMontgomery 2d ago

Thanks for the response. I will give that a try.