I noticed other fan covers for 40mm fans required longer screws or additional hardware to assemble. I designed this to be an easy solution for those looking to protect your fan. I also uploaded the solidworks part file if you would like to make changes. If you print this, please create a make for it, would be pretty cool to see it on other people's printers!
Attaching to fan: https://youtu.be/fcw58m7IJSA
Edit: Added a version with diagonal posts