DAVANCI ROLLING BALL TIMER. New complete mold. The Da Vinci roller ball timer is based on a sketch of an exhaust mechanism designed by Léonardo da Vinci.\nThe kit uses the principles of gravity and kinetics to measure the passage of time.\nHe uses precision gears to supply a platform in a \"saw\" scheme that propels a bearing ball.\nOnce finished, it presents concepts relating to the laws of movement and offers hours of entertainment. The Di Vinci rolling ball timer is based on a sketch of an exhaust mechanism drawn by Léonardo da Vinci.\nThe kit uses the principles of gravity and kinetics to measure the passage of time.\nHe uses precision gears to supply a platform in a \"saw\" scheme that propels a bearing ball.\nOnce finished, it presents concepts relating to movement laws and offers hours of entertainment.