Number lock

This (mostly-flat) kit card is a bit of a challenge to make but will produce a working 3-digit combination lock, just like the one you used to have on your high school locker. Well, sorta like that one. It requires an impeccably tuned printer (some of the parts are very tiny), a steady hand, tweezers, and maybe some magnifiers. It prints without supports and snaps together without any glue, fasteners, or other hardware.I learned how a combination lock works from this video, and based this design