November 2, 2017
Description
I took the really cool design from kpawel and improved it a bit for my purpose.
The main idea was that the square holes have a 27% wider opening surface without letting the round particles fall through any easier (the holes are still 1.5mm wide). Also a sphere and a square hole can never form a seal unlike a sphere and a circular hole. Furthermore I put more holes of them in the same area.
All three measures should improve circulation of air and boost effectiveness.
As a side effect it prints faster and with less material. In theory my version would not be as stable as the original, but I didn't find that to be an issue (it's still quite tough).
I like kpawel's idea to print transparent and highly recommend it if you have transparent filament.
License:
Creative Commons - Attribution