Bicone-Pivot Filter Grille Turn Clip
A two-piece print-in-place swivel clip that replaces a missing filter retainer on a return-air grille. You fasten it to the grille frame flange with one #6 or #8 wood screw, or an M4 bolt, through a 4.5 mm sleeve. Then you swing the 58 mm × 16 mm arm over the filter edge to hold it. The arm turns on a double-cone (bicone) bearing with a 0.5 mm gap and 45° faces, so it prints without supports and can't slide off the sleeve, even before it is screwed down.
mechanism hvac filter-grille turn-button