the term is much better known as a nickname for the Mazda RX-7 — one of the few cars that used a Wankel, or rotary, engine. If you ever wondered how these worked, why not print a model?

Mazda's Wankel rotary engine has always been unique in the automotive landscape as a mass-produced internal combustion engine that eschews such unsightly items as pistons, valves and camshafts.