3DPrinting

cross-posted from: https://lemmy.ml/post/36080579

I got a Prusa CORE One earlier this year, and so far I've been very happy. I have not ventured outside of the default settings though, and I use their own filament (only PLA). This has worked perfectly fine so far, but now I ran into an issue, and I figure it's time to come out of the "default settings"-bubble and learn some more about this stuff.

I am trying to print a Gridfinity holder for a rolling pin, so I tried to cut out a appropriately sized cylinder in a template with a boolean operator in Blender. When the print got to the concave portion, the print started to fail - uncertain how to best explain it, but the overhangs over the infill did not properly bridge and the filament started to warp so that the print head would hit it on the next pass (and make some nasty scratching sounds). I stopped the print when I noticed this. See an image here:

I am uncertain whether this is due to the model being poorly optimized for 3D-printing, if the printer settings for the filament were off or if I could've tweaked the slicing settings to achieve a better result.

Is it obvious, looking at the image, what the primary reason for this failure is?

Note: I've ended up printing this again already with a regular rectangular cutout instead of a cylindrical one, so I am just trying to learn more about what made this fail to learn more.