A friend asked me to make one of these cutting board mimicking a puzzle piece.I had some 18 mm beech board laying around so I made two of them. The interlocking part is designed a millimeter smaller so the fit is not too tight.
When cutting the two parts on my CNC I made a little mistake using the CAM: I mistyped the depth per cut and did all 18 mm in one go at a speed of 1800 mm/min. I was a little worried first, but it worked quite good.
After cutting I used a little hand router to round over the edges, sanded the final pieces and oiled them with mineral oil.
I am not sure if the STL-file is useful for anything other the 3-d-viewing but you are welcome to use it for maybe a smaller version.
Visit https://www.zenziwerken.de/en/ for more interesting designs.