DesignPuzzles galore: Oskar van DeventerTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoDesign07/19/2018July 19, 2018Oskar van Deventer from the Netherlands has invented more than 500 mechanical puzzles. He presents new ones on YouTube each week. They’re produced with a 3D printer.https://p.dw.com/p/2jO10Advertisement