Updated STL Files, Exported with 1mm per unit This puzzle you can either 3D print or make using some M16 & M8 Brass nuts and bolts, you will also need a 4mm x 2mm round neodymium magnet. and a 10mm x 4mm steel rod (cut a piece of 4mm nail) Thanks to Grabcad User Heatniks for the original bolt and nut drawings. http://grabcad.com/heatnix The origional idea for this puzzle is based on a puzzle from "homemade puzzles" http://homepage.ntlworld.com/bruce.viney/Bolt%20Puzzles%20Secrets.pdf You can find more detailed instructions here: http://www.instructables.com/id/Brass-Bolt-Puzzle/How it works: Get the washer off the bolt. The idea is the magnet is glued into the top section of the main bolt with epoxy. Which will hold the steel rod in place when the assembly is together. To open the puzzle you need to slam the base on a hard surface. to allow you to remove the other parts of the puzzle so you can remove the washer.