I love the Thing JKSniper made here. https://www.thingiverse.com/thing:2105113
But the middle grill will drive you nuts if you're trying to change it in the enclosure. I simply remixed his STL files to make something a little easier to work with that does the same thing but more secure without all the alignment issues of the original.
FYI I had to use the STL files and import those into Solidworks then build up and assembly to get the right geometry. It's not perfect but you really can't tell once it's printed.