Joel Gomes has created this 3D-printed model of a Wankel engine, which fits together well enough that it functions as an engine – though instead of using exploding hydrocarbons, he’s elected to use compressed CO2. Joel had to adapt a quick-release valve, tapping a thread to add an electrically controlled release mechanism to enable him to release the gas into the Wankel engine remotely. It’s currently powering a remote-controlled car, in a brilliant mix-up of 3D printing and steampunk.
Instead of pistons moving up and down, with a crank to convert linear motion into rotary motion, a Wankel engine uses a triangular rotor that turns within a chamber. As the triangle rotates, different areas within the chamber get compressed. When petrol and air are injected, and the mixture ignited, the triangle spins fast enough to power a car, motorbike, or aircraft. Wankel engines have advantages (high power-to-weight ratio, low
vibration) and disadvantages (poor fuel efficiency, a tendency to break down if not maintained) compared with standard piston engines, but we like them mainly because of the clever, original design – which also translates well into 3D printing.