Re-keyable Cryptex
Based off the cryptex from The Da Vinci Code.
Print off both shells, 5 pin wheels, and 5 of the letter wheels of either type. Letter wheels come in both embossed and plain, to allow you to add your own symbols. To assemble, stretch a pin wheel over the outer shell until it is in the groove closest to the end plate, with the gap aligned with the gap in the case. Then take a letter wheel and slide it onto the pin wheel so that the letter of the combination is over the gap in the wheel. Repeat with all the pin and letter wheels alternately until all 5 have been added. Make sure all the gaps are lined up and slide the inner shell inside. To unlock, align the word with the marks on the shells and carefully pull the shells apart. If the letters aren't perfectly aligned, there is a risk of breaking the pins on the inner case
Created by me in onshape Example picture was printed with black PETG at 0.2mm and white PLA at 0.12mm on an Ender 3 V3 SE