Inspired by these mechanical movements animations, I thought it would be fun to figure out how to make some gears out of one of my favorite building material, cardboard. Turns out making working gears is harder than I thought. I thought one gear 12" in diameter with 16 teeth and one 6" in diameter with 8 teeth would work well, and I guess they could if the teeth were designed correctly. My gears stick because the teeth catch on each other. Further research is needed, but I would like to find something easy enough to cut out of cardboard yet able to move easily. There is a lot of information on spur gears, which is what these turn out to be.