Knowledge Zone

CNC Feed Drives

The feed drive systems are the key elements of numerically controlled machine tools. Almost everything depends on them - from positioning accuracy, speed of working movements, acceleration and smoothness of movements. The requirements we place on such drives today are very high.

Professional solutions require the use of servo drives, and in the case of less demanding applications, stepper motors are sufficient. We offer both types of feed drives. The main difference between these drives is the position feedback. In the case of stepper motors, all machine movements consist of a very large number of individual steps generated by the interpolator. Each step, depending on the drive ratio and the number of microsteps, is 0.005 to 0.1 mm. Drives of this type are characterized by a very simple structure, which results in a relatively low price. A certain inconvenience is the lack of position measurement and in some unfavorable circumstances (overload) the loss of coordinates (missing steps) may occur, which may damage the workpiece or tool.

Servo drives do not have these drawbacks. Their work consists in constantly striving to achieve a zero error, that is, the difference between the set value and the measured value. The position of the head is constantly read using incremental encoders that can measure the position of the head with an accuracy of up to 0.001mm. Based on this information, the control system controls the engine so that the error is zero. When the load is increased, the engine increases power, preventing a position error, and in the event of exceeding a certain load, the system stops the machine and informs the operator about the need to intervene.