This amazing papercraft is an Automata Gear Heart, designed by Haruki Nakamura. The gear heart is composed of 9 pieces of 10-cog, and 3 pieces of 15-cog; in total, 12 gears. 10-cog returns to the same position after 3 rotations.
In the same time, 15-cog makes 2 rotations. 10-cog makes a rotation with one rotation of handle. Therefore, 3 rotations make to regain the original figure.You can download the papercraft template here: Automata Gear Heart Free Papercraft Download