Shenzhen Stepper Technology Co., Ltd. 1. Introduction In recent years, servo systems have matured significantly. Due to their excellent operating characteristics and high-precision positioning, servos are widely used in various industries. The old-fashioned manual positioning or stepper motor-controlled cutting machine systems can no longer meet higher precision requirements, making the replacement by servo systems inevitable. This article mainly discusses the successful application of servos in PC-controlled wire EDM machines, using Kinco high-performance servos as an example. 2. Main Components of a Wire EDM Machine Machine tool, servo motor, text controller, PLC, motion control card. The machine tool consists of a bed, XY worktable, oil tank, etc. The motion control card has main functions such as gap compensation, linear interpolation, and circular interpolation. 3. Working Principle of a Wire EDM Machine The workpiece is fixed on the XY worktable. Movement in both the X and Y directions is controlled by a servo motor. The mechanical points to be positioned are pre-input by the text controller, and then the reference zero point of the machining center is determined. The positioning point is sent to the servo driver. The servo motor drives the lead screws in both directions to rotate through the intermediate transmission mechanism, thereby feeding the X and Y tables respectively. After positioning, the host computer sends an interpolation motion command. The positioning motors in the X and Y directions perform interpolation motion, while the cutting motor cuts holes of different shapes according to the direction of the positioning motor. Figure 1 4 Features and functions of Kinco servo 4.1 Programmable program control Built-in 256-segment programmable capacity of sequence. Each sequence program can be written with 8 statements, for a total of 2048 programmable steps. The program can be triggered through external digital I/O ports. For example, the ED100 driver has 8 DIN ports. The digital input ports can be connected to a DC 24V control power supply. DIN6 and DIN7 can be used for positive and negative limit switches, DIN8 can be used for origin return, DIN1 to DIN5 can be defined and called by the user, and DIN6 to DIN8 can also be defined and called as sequence programs. When there are many programs to be called and the digital input ports are insufficient, BCD encoding can be used. The digital input port has an input interval time of >1ms. Due to its powerful programmable function, it can eliminate the need for a PLC or other host computer in some applications, making the control system simpler, the cost lower, and the integrated product more competitive. Figure 2 shows an example of a sequence. 4.2 Calculation Functions, Comparison Functions, Timing and Counting Functions, Data Recording, and Customized Firmware Arithmetic Unit: The Kinco servo drive provides an internal arithmetic unit capable of simple arithmetic and logical operations. Comparator: The comparison function allows users to perform internal comparisons, such as setting a target pulse count in position mode and comparing it with the actual position in real time during operation. When the comparison is reached, the corresponding sequence program can be called for related control. Timer: Provides a counter with a minimum time base of 1ms for delay control. Counter: Allows users to connect to external pulse input devices for counting control. Data Recording: Allows temporary storage of user data or calculation results. 4.3 Communication Functions The Kinco servo has powerful communication capabilities, supporting CAN OPEN and PROFIBUS protocols. It provides CAN, PROFIBUS communication interfaces, as well as RS232C and RS485 communication interfaces. Users can easily communicate with the drive via a host computer or expand IO modules through the CAN communication port. The universal transmission protocol allows users to master the usage skills in a short time. 4.4 Customizable Firmware In certain specialized industries or applications, when existing low-level programs cannot meet user needs, firmware can be modified to achieve the required control. 5 Parameter Settings Before starting positioning, the points to be positioned must be set via the text controller. The input will be saved to the PLC's power-off retention register. Then, the positioning speed, origin-finding speed, and other necessary parameters are input. The parameter setting screen is shown in Figure 3. Figure 3 6 Positioning Operation Once all parameters are set and the mechanical device is ready, the positioning button on the text controller can be pressed. The PLC will then send the positioning point and positioning speed to the driver via communication for positioning. The positioning accuracy can reach 0.005mm. After positioning, the motion control card sends pulses to control the driver for interpolation positioning control, and the cutting machine starts simultaneously. 7 Applications of Wire EDM Machines (1) Widely used in various punching dies (2) Processing small irregular holes, narrow slits and various complex shapes of workpieces (3) Processing templates or forming tools (4) Processing powder metallurgy molds, inlaid cavity molds, wire drawing molds, corrugated molds and forming molds (5) Processing hard materials, cutting thin sheets, cutting precious metal materials (6) Processing cams and special gears (7) Suitable for small batch and multi-variety parts processing, reducing mold manufacturing costs and shortening the production cycle. 8 Conclusion After equipment debugging, all performance indicators have met customer approval. The Kinco servo wire EDM machine has been applied and has also received positive feedback from users. Proceedings of the 2nd Servo and Motion Control Forum Proceedings of the 3rd Servo and Motion Control Forum