What kind of machine did Leonardo da Vinci design for producing continuous motion from weights?

Leonardo da Vinci designed and analyzed a perpetual-motion machine, though it could not actually run forever.

His notebooks include wheel-and-weight arrangements intended to keep turning as falling weights produced torque. Leonardo studied these mechanisms partly to expose why they failed: the weights could not produce more energy on one side than the other, and friction steadily removed useful motion.

The design is important because Leonardo was not simply claiming success. His notes show skepticism toward perpetual motion and an effort to demonstrate the mechanical reasons such schemes stop. This makes the drawings valuable as examples of Renaissance engineering analysis.

A perpetual-motion machine would violate the principles of thermodynamics if it produced continuous work without an energy source. Leonardo’s experiments therefore belong to the history of mechanical reasoning, not to the history of working engines.