Fidget toys all have a satisfying mechanical action to engage with, and [uhltimate]’s OTF (out the front) “fidget knife” model provides that in spades. The model snaps open and closed thanks to a clever arrangement of springs and latches contained in only three printed pieces.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/05/08/3d-printed-fidget-knife-snaps-back-and-forth-all-day-long/