The Impossible Puzzle Made Possible by FDM Printing

I designed this puzzle after seeing something similar by Mr. Puzzle. By 3D printing the puzzle you'll know the secret mechanism that makes it possible so it's no longer really a puzzle for the maker. However, its sure to stump your family and friends. Unlike the wooden versions that have glued joints, FDM printing makes the piece seamless and a real puzzle to those who do not understand what's happening inside.

I designed the holding compartment (cage) to either hold a spark plug (https://am