120 mm grille for fans low pressure drop for air purifiers

This is a grille that passes the UL 507 finger probe test, is printable, and has lower pressure drop than the grilles you can buy. 40 cc of filament is only $1 or so to make from PLA. Remember PLA has limited heat resistance, also modified pla might be a good idea to avoid stress cracking near the bolt head. I used a 0.6 mm nozzle, 0.4 would probably be fine though. I set the road width to 0.75 mm. Step file and original fusion 360 file included, this is important to make modifications easy. You can easily change the grille element thickness for instance to accomodate smaller nozzles more easily with a single parameter change (the surface thicken). This is open source, MIT license, do anything you want with it for any reason basically. You can use M4 bolts with nuts or M5 bolts to grab the plastic of the fan directly.