As seen on Chinese wholesalers, this is a replica of the impossible dovetail puzzle box. It is ingeniously simple in design, but it can boggle an expe...rienced puzzler's mind for a stretch.
Fair warning: there are sharp points and edges, and the tolerances for the ball bearing might require you to hone out the holes a bit.
If you remake this, for attribution please simply note that it was inspired by the wooden puzzle boxes found around online.
Note: TWO magnets are REQUIRED for this to work properly! Also one ferrous 3/8" (9mm) steel ball bearing. If you use a 10mm version, enlarge both holes appropriately.
3d model print parameters
Monoprice Select Mini v1
4mm thick shells/walls or larger. ...This gets hit a LOT with sharp strikes! Also, be aware of sharp edges, corners, etc.
8mm Neodymium magnets or smaller + 9mm or 3/8" steel ball
Before you start, check the ball to see if it moves freely in the top hole. Hone out the hole as needed. Use two identical magnets, with the same pole facing each other, using polyurethane or acrylic glue. The steel ball must jump from the bottom magnet to the top magnet to unlock the box, which requires a sharps strike.