i think i finally finished the ducts…
these were nightmarish to make. onshape conveniently doesn’t have 3d sketches, so I did a horribly janky system involving planes and a routing curve. The path the duct had to take ended up being kinda strange, so the loft would constantly crash out because the profiles turned too sharply. i did eventually get the loft to cooperate, and the duct looks okay? it’s still very lumpy, but it should transition relatively smoothly, which is what’s important for airflow.
i’ve also started printing the parts now. as i’m typing this, the main mount is finished and the fan mount is almost done. after that i should theoretically be good to assemble once i print the ducts

(this is the video i used for duct design principles: https://www.youtube.com/watch?v=YijwkQCOBEA)