A bow is composed of a flexible rod, usually made of wood, whose ends are connected by a fine cord (nowadays made of nylon). The cord wraps around a pulley which drives a piece for turning or drilling operations. The bow lathe thus has the same role as the drive belt of a lathe or any rotating machine (drill, milling machine etc.). It allows the craftsman to control the rotation speed of the component with great sensitivity. This device is the oldest intended for driving rotational movements. However, it has two major drawbacks: It requires one of the craftsman’s hands for this role and systematically implies an alternation of the direction of rotation of the tool or component.