This is a cryptex I designed for giving lottery tickets away as gifts but you could use it for anything you could fit into it. The crytex can be dis-assembled and the code changed to anything the user wants using letters. I send them out with the code used on the Da Vinci Code cryptex and give them hints so they have to figure it out.
I printed everything on low resolution and lightly sanded the assembled wheels for smooth operation.
I added an option to print with flat ends since some have trouble printing the rounded version.