Screen cover for 4" air inlet

prusaprinters

This is a removable screen cover for a 4" combustion air inlet (e.g., furnace, water heater, etc.). I found that the metal fitting inside frosted over too much in cold weather, and I hope I can leave this one on year-round (I'll update this after the winter). If it does frost over, it will be much easier to remove than the metal one.There are two versions:R3 - This is the one pictured, it has a slightly wide spacing than the original grate (15mm) and has a rounded bottom.R4 - This is a newer revision, it has a narrower spacing comparable to the original grate (11mm) and has a chamfered bottom which prints more cleanly.Dimensions:102mm inner diameter (4")Clip is 40mm high with a 4mm overhang and 45 degree insertion/removal angleBase grid is 4mm highI designed this with OpenSCAD and it's fully parameterized; if you would like one with different dimensions just let me know.