I needed a cover for a fan on an intake of a 140mm Noctua fan to help ensure it does not get damaged and designed this grill to fix the problem and added an optional variant.
One design has fins and one design is completely flat. Please review them and choose which one suits you best. These fit nearly any 140mm fans as the screw holes are in a standard location.
This model has been designed to with its back flat on the print bed with no supports. I used PLA which worked fine.