Abstract: The cabinet of the numerical control device contains a memory, a frequency changer, an amplifier and two correcting units. A programing station with keyboard and mounted on the cabinet enables programing the memory. The control device further comprises an encoder and a DC motor. It shall be associated with a lathe mechanically controlled by cams. The encoder records the successive positions of the camshaft and transmits these informations to the memory. In accordance with these informations the latter transmits mandatory instructions to the frequency changer and to the amplifier which modify the motor speeds and, consequently, those of the spindle and of the camshaft, to an extent dictated to the memory by the keyboard. At the beginning of particular machining steps the memory can activate the correcting units thus permitting to modify the instructions of the memory in order to find out the optimal speeds after some tests.