Abstract: The system is applied to a lathe and allows control of the machine to be adapted in such manner as to make use of the maximum power of the spindle motor with the maximum feed of the tool and the minimum cutting speed. The feed rate and the cutting speed are defined by the programmer only as the permitted region within which these parameters must jointly lie. The control unit tends constantly to command the feed rate and the spindle motor in such manner as to be within this region. Then the control unit compares the power consumed by the spindle motor, which is detected by a circuit through the armature current, with the maximum power of the motor for the actual working conditions and tends to cause the feed rate and the number of revolutions to be adapted in such manner as to make use of this maximum power. The system is adapted to exclude adaptation during cutting-in-air operation.