A Clip-on fan cover for Arctic F9. Just push this cover into either the front or back of the F9 and it will tightly snap into place.
This model was specifically designed to fit the Arctic F9, and I haven't tested if it fits any other fan models. It is possible that other 90mm fans are compatible.
I designed this because I had a few Arctic F9 fans laying around, and wanted to use them as a desktop fan. Although the fans work well, they are quite the safety hazard.
Therefore, to make them safer to use, I clipped these covers on both sides of the fan. Now my fingers are safe from the spinning death blade.
There is a .STL file you can use for printing, and a source .blend file you can use to customize the model.
The tolerances are very tight, so make sure your printer is well-calibrated.
My printer settings
Creality Ender 3
PLA filament from Sondori
Nozzle @ 200℃
Bed @ 60℃
0.2mm Layer height