The plastic cover for my kitchen fan broke and I couldn't find any retailer that sold spares, so I designed a new one.
This design prints in four parts, and is then held together by 4xM3x18 screws and 4xM3n nuts. Longer screws work too, they will just protrude a bit more but that is not visible anyway. There are also tiny slots for cable ties for extra stability, but I ended up not using those.
Printer settings:
White basic PLA (shouldn't get too hot there anyway, but PET might be a better option for a bit more heat resistance.)
0.20mm layer hight and a 15% infill.
Some supports needed for the protruding “flaps” and I also placed some in the cavities to ensure they don't sack down too much.
Make sure you print one of each corner!
The author hasn't provided the model origin yet.