This is a classic puzzle and the pieces could be made in a number of ways, but having the precision-aligned CNC holes is visually appealing, and pocketing them out felt safer than using my drill press. A machine fit for the “buttons” could be designed but I did not take that route.



The main square is 2.55" × 2.55" × 1.4". I used a thickness and width of wood I had available, hence the strange dimensions. I put the design together in Illustrator and exported SVGs into Carbide Create. I used a 0.25" end mill and a 60° Vee bit to bevel the buttons and holes. One could easily add more pieces but I feel 6 pieces (and two bases) is an appropriate level of complexity. There is also one duplicate piece.



The puzzle has taken both of my test subjects about 25 minutes to solve.



The pieces are probably best cut out on the CNC. I planned to draw the outlining rectangles using a CNC pocket and then use a table saw to cut them out. I would recommend using the CNC and tabs to dimension everything. This should improve safety and reduce sanding time.



The origin for the "top" cuts was the bottom left, and the origin for the "bottom" cuts (after flipping along the y-axis) was the top left. This allows for referencing both cuts off the same physical location.



Plan your containing box ahead of time! Consider oversizing the bottom and top hole grids so they fit in rabbets. My box has simple butt joints with homemade walnut dowels. I haven’t included any “plans” for the box as part of this project.