120mm Fan Grill for Filter

thingiverse

I built a simple printer box and set up two 120mm exhaust fans. These grills hold a charcoal filter (purchased pack on Amazon) on the intake side of the fans. I added a standard metal grill on the fan intake side to prevent the filter from interfering with the fan blades. You could easily do it with a couple 1/8in spacers as well (custom grill > charcoal filter > 1/8in spacer or metal grill > fan > mounted to box). This grill has two pegs spaced on opposite corners that line up with the screw holes on a standard 120mm fan. It is a simple pressure fit. If your fan is mounted on the top of the box, it will probably require a set screw to hold in place. When placed vertically, they hold just fine.