Need you help figuring this mystery issue for me. I am doing a few flow rate test to find the max flow rate with my PETG filament, and I noticed that there’s always some rather regular defects showing up when z height is beyond ~25mm.
Attaching 3 photos showing the issue from 3 different flow rate prints. What I can be sure is below:
They all are running at very different flow rates, so flow rate or print speed is not the issue.
They are all on the same PETG filament. Although I have no other filament at hand right now, I am sure I’ve printed much taller objects without seeing similar issue.
I’ve tried to change fan settings a bit but I don’t think it affected the issue.
Note that the dent / notch like defect always show up at similar spot
All of these are printed with only bed leveling, no flow calibration or time lapse recording. so unlikely they are the cause of it.
At a guess, walls are too thin/unsupported. Taller they get, the wobblier they get. That’s why the patterning doesn’t occur right at the corners (there is some shifting there, too, though), the walls are “stiffer” there because they’re curved. Or near the bottom where they’re more “coupled” to the horizontal bottom. The extruder nozzle is pushing on the print as it passes over it and the tall thin walls “squirm” around some more in the middle where the corners aren’t helping hold it in place.
Thanks for the reply. I thought about the wobble, but what I cannot explain is that this side also is a straight line, that I can see minimal wobble until it reaches the corners. However I have no idea how to prove that’s not the reason.
Add some internal “webs” to tie the walls together. The print won’t be functional as a result, but if the problem you’re having is that the walls are squirming when they get tall enough, this would prove it I think…
No it is not - the 3 prints are done at different speeds. The first one was the slowest, from 11mm3/s to 35mm3/s, and the last one is from 35mm3/s to 50mm3/s. The last one does not show any issue at speed higher than the highest speed of the first one.
