This simple print-in-place flap automatically flips out to let you know when mail has been delivered. This only works mailboxes with the lid on top!

Printing Guidelines

Prints in place. 0.16mm layer height, 4 shells, 6 top and bottom solid layers. PLA may work in less extreme climates, but ABS, ASA, or PETG may be better for longevity, especially if you experience very high temperatures.

To install, use acrylic double-sided tape or VHB tape up to 20mm wide to stick the short end of the hinge at the edge of the mailbox lid. Make sure the hinge rotates easily, gravity should do the rest!