Stripping/burring of outer wall on upwards facing 45 degree angle

[S.Ferrari]

My parts have been coming out with this sandpaper like surface finish on any top surface that is at a 45 degree angle (the part is printed as shown in the second photo). Has anyone seen this before? It seems to be the outer walls separating and solidifying into these burrs. All other surfaces turn out perfectly, no signs of extrusion issues.

I have been messing around with Z contouring (anti aliasing) and a few other features for the first time. I did some testing on some sample prints and thought I eliminated this issue but it’s still happening with z contouring enabled.

Printed with dry generic PETG on my P1S, all changes to standard 0.4mm nozzle preset in OrcaSlicer listed below, as well as the .3mf attached.

Brute2GoV6.3mf (7.3 MB)

Quality:

- scarf joint seam (beta): contour and hole

- scarf joint speed: 80%

- wipe on loops enabled

- Z contouring enabled

- extra bridge layers (beta): apply to all

- filter out small internal bridges: limited filtering

- extra perimeters on overhangs enabled

- reverse on even enabled

Strength:

Wall loops: 3

Top surface pattern: concentric

sparse infill density: 9%

sparse infill pattern: gyroid

internal solid infill pattern: monotonic line

align infill direction to model enabled

infill combination enabled

infill combination - max layer heigh: 80%

If anyone has any insight as to what combination of things are causing this it would be greatly appreciated. I figure it’s something to do with the Z contouring combined with another factor, I can visually see the nozzle skipping on the separated plastic and it almost looks like chip breaking in CNC where the line of plastic gets interrupted.

Cheers!

[EnoTheThracian]

What is your print speed? With non-HF PETG, I stick to speeds below 80mm/s.

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[CarbonForge]

You’re got something seriously wrong happening on all of your outer walls, not just the overhangs.

I suggest you start with clean settings and a simple test shape to see if you can get clean prints, then re-add changes one by one.

Is there a chance your nozzle on the printer is smaller than the one you have selected in the slicer?

[S.Ferrari]

200mm/s…. I feel real stupid that I didn’t notice that was the default value. It’s really strange I wasn’t having any issues right up till now.

[S.Ferrari]

Yeah the outer walls all around aren’t adhering to the inner walls very well, the surface finish is good but it’s just delaminating everywhere. I’m gonna raise the nozzle temp and do some printing speed tests.

[EnoTheThracian]

There’s nothing stupid about using defaults. Not your fault they are what they are.

But since you seem to have changed a number of parameters in parallel, it may best to go back to defaults, slow down and then just change the one parameter you want to learn about rather than changing several at the same time.

Also, when using “combine infill” with PETG, I have found it useful to have a look or two mid print.

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