Modern CNC system is a pure electrical control system. The movement of the feed axis is carried out by the servo motor. Usually, a feed shaft is driven by a servo motor. The motor is powered by a servo amplifier. The work of the servo amplifier is controlled by the distributed output signal of the CNC interpolator.

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Adoption of programmable controllers | #CNC

Adoption of programmable controllers

Before the 1970s, the sequence control of NC controllers and machine tools was mainly carried out by relays.