This remix uses cheap 1mm steel wire as pivot pins:
https://www.amazon.com/Hillman-Group-123133-Galvanized-50-Feet/dp/B003B4VHHM/
The included frame needs 14 flaps, and 28 qty of 3/4" lengths of 1mm steel wire.
Instead of bending the flaps to insert them, you push through lengths of wire.
ventFlaps.stl | 84.9KB | |
ventFrame.stl | 131.9KB |