Lego interlocking solid puzzles
Apart from the fact that the bricks and plates are open at their bottoms, and so the pieces always have one side that can’t be “smooth,” Lego is a pretty handy way to prototype interlocking solid puzzles. Many of these are based on cubic units, and can be built in Lego at a scale of 1 cube = 2 studs x 2 studs x 5 plates.
Eric Harshbarger, whose Lego hijinks we’ve featured a couple times before, has produced some lovely models based on this principle. Shown above are his 6-piece burr, checkered solid pentominoes, Soma cube, and deluxe polycube set. The awesomeness continues at Eric’s site.