CNC Cut Shelf
The woodshop at my high school had recently acquired a CNC router, and the engineering teacher was excited, so he had my class design furniture that could be cut from a quarter-sheet of plywood. We worked in groups of two, and this is what me and my partner came up with.
We did the 3D design in Onshape. (for those who haven't heard of it, Onshape is a cloud-based in-browser CAD program.) The model went through about three iterations before it was finished. There's a picture of the final version on the right. We then transferred 2D outlines of all the pieces into Vcarve so we could send them to the CNC router to be cut. We cut out two copies, and assembled them with a wooden mallet. The toothed joints at the corners turned out to be so tight that the shelf stays together without screws.
This experience with toothed joints influenced how I designed the shell of the Jankó synth years later.