Aperture door for a 120mm fan. Perfect for an enclosure that prints PLA and ABS.
Video of my enclosure with the fan doors in use:
Assemble the 5 door blades onto the base with the grooves on the blades facing up.
Place the ring on top with the pins printed onto it in the groves of the door blades.
Use 5 m3 x 5mm screws with washers that are wider than the grove on the ring.