Cap for a PVC pipe with ~90mm outside diameter.
I needed a vent cap for my high-efficiency furnace blower vent.

To make this work, you have to slice it with zero (0) top and bottom layers to expose the infill pattern you choose (I use only 10% fill). I've included the Cura 3MF file, as well as the gcode for an Ender 3 using PETG

Creality

Ender 3

10%, choose your pattern