What machine did Leonardo da Vinci design with a rotating drum and winding mechanism to move itself?

Leonardo da Vinci designed a self-propelled cart powered by springs, drums, and a programmable steering mechanism.

The cart is usually dated to around 1478–1480 and is often described as an early ancestor of the automobile. Wound springs stored energy, while drums mounted on the cart controlled the movement of the wheels. Pegs on the drums could be arranged to set a steering pattern, allowing the cart to follow a predetermined route.

Leonardo may have intended the device for theatrical performances or court spectacles rather than transportation. It was not an engine-powered car, and its range and control would have been limited. The surviving drawing is incomplete, so modern reconstructions rely on interpretation of the mechanism.

In 2006, an Italian team built a working reconstruction based on Leonardo's plans. The machine moved under spring power, confirming that the basic principle was feasible. It should not be confused with Leonardo's armored vehicle, which was a military design with cannons and protective plating.