Customizable Fan Grill Cover by mightynozzle  (https://www.thingiverse.com/thing:2802474)

I wasn't satisfied about the most of the fan covers available on thingiverse, because the finer details aren't optimized for 3D printing. That's why I designed this customizable fan cover, where you are able to use different settings to create your own fan cover.

Check out the second picture for some of the available settings and the 3rd picture to sync the line size of the fan cover with the line width of your slicer. Use the Customizer or OpenSCAD to create your fan cover or use the pre-compiled fan covers as .stl-Files, optimized for 0.48mm line width (0.4mm nozzle).