Oskar Key was originally designed in 1987, based on an idea from 1984. This two-layer puzzle key was mass-produced in metal by the Japanese Hanayama toy company. It was the very first licensed design by Hanayama. Production has stopped a long time ago, and vintage samples are occasionally sold at Ebay for 1000 USD. Several people asked me for a 3D-printable sample, so here it is. To make the puzzle even more challenging, I added a third key in the middle. The underlying mathematical concept is Prof. N.G. de Bruijn's Beer Bottle Problem (see https://vixra.org/pdf/1208.0223v1.pdf, page 110), who proved in the 1960's (?) that such puzzle is always solvable.
Watch the YouTube video.
Read at the iMaterialise Forum.
Read more at the Non-Twisty Puzzles Forum.
Please order a 3D-printed do-it-yourself puzzle kit from iMaterialise at this page (check with Oskar about screws and stickers), or contact Oskar directly if you are interested in obtaining a fully colored, stickered and assembled sample of this puzzle.
Oskar van Deventer
Oskar Puzzles offers mechanical puzzles and objects that can only exist thanks to 3D printing technologies. All designed by M.Oskar van Deventer.