Abstract: This paper introduces the application of the Luosheng ELMO multi-axis controller in a fishtail grooving machine, highlighting its use in grooving equipment. It also discusses the advantages of CAN bus control and the performance improvement of stepper motors by servo motors. Keywords: Luosheng servo motor, bus system, stability, Elmo I. Introduction to the Fishtail Grooving Machine The fishtail grooving machine (Figure 1) is a type of precision industrial machinery used to produce drill bits and milling cutters for precision PCBs and BGAs, requiring high precision and stability at low speeds. The X, Y, and Z axes are used for machining. The Z-axis is the rotary axis, where the cutting material is clamped and rotates. The X and Y axes are the cutting material seats. During each machining operation, the repeated movement of the X and Y axes ensures the cutting material is ground by the grinding wheel at different positions, thus shaping the tool. The X1 and Y1 axes control the position of the material tray. X1 moves left and right, and Y1 moves up and down. The movement of X1 and Y1 ensures the order of material handling. The required speed for each axis is not high, basically below 200 rpm (without a reducer). The lead screw lengths for the X, Y, X1, and Y1 axes are: X: 180mm; Y: 200mm; X1: 200mm; Y1: 250mm. [align=center] Figure 1 Fishtail Trenching Machine[/align] II. Electrical Configuration Scheme for the Trenching Machine [align=center] Figure 2 Electrical Configuration Scheme for the Trenching Machine[/align] The new electrical scheme shown in Figure 2 uses a 5-unit architecture of Rosen HITECH HMI + axis controller (Rosen ELMO Maestro) + Rosen Elmo servo (Basoon). The multi-axis controller is expanded with Wago's DS401 output module supporting the CAN bus protocol (16 output points in total). The HMI still uses the Rosen HITECH model 3261 10.5-inch. III. Features and Advantages of the New Solution 1) Power Supply System: The ELMO Basoon-5/230 power supply system incorporates built-in filters and recovery resistors, significantly extending the driver's lifespan. It shields against voltage fluctuations from the factory power grid, ensuring a stable DC voltage supply. The built-in recovery resistors also absorb feedback voltage from the motor during high-frequency start-stop cycles. Furthermore, this driver complies with UL and CE certifications. 2) Bus System: The system utilizes the popular European CANOPEN bus, renowned for its high-speed and stable data transmission. The communication protocol between MAESTRO and the ELMO driver is based on DS402 (a CAN protocol specifically developed for motion control), a unique ELMO protocol. This allows for a more seamless integration of the ELMO driver with the CAN communication protocol. Therefore, ELMO products are not merely CAN-compliant servo drivers; their language, control methods, and network are also tailored to ELMO's specific characteristics. 3) Controller (Luosheng ELMO MAESTRO): MAESTRO is an ELMO control product. It is backward compatible with Ethernet and RS232 communication protocols. Internally, it uses a Motorola 32-bit DSP processing chip and Microsoft WINCE system, with a built-in 64MB hard drive (ample storage space). It is backward compatible with CAN networks (DS301, DS402, ELMO protocol) and can control up to 256 axes. The ELMO protocol allows for data transmission in just 200 microseconds. MAESTRO also features a dedicated ELMO callback function to ensure real-time data transmission while significantly reducing network load. MAESTRO can also use Ethernet for convenient remote maintenance. It has built-in programmable I/O and can be freely programmed and controlled. 4) Servo System: Currently, the Luosheng ELMO system, with its outstanding stability, ultra-small size, and powerful functions, has been adopted by many military research institutes, medical equipment manufacturers, and multi-axis linkage manufacturers in China, and has received high praise. The Luosheng ELMO servo employs PIP control based on speed and environmental standards, simplifying debugging. Its built-in 64 PID controllers ensure smooth, high-speed operation at full speed. Simultaneously, the high-speed position loop sampling time (240 microseconds) and speed loop sampling time (120 microseconds) result in more precise positioning and smoother speed fluctuations. It also features 5 built-in filters and can perform FFT (Fast Fourier Transform) to obtain the system's resonance point, reducing system resonance. A smoothing coefficient can be set within the driver to reduce system impact. Furthermore, it utilizes a 22kHz carrier frequency switching period, resulting in better current characteristics from the servo driver to the servo motor. 5) Wiring Advantages: CAN BUS control of the system significantly reduces wiring within the electrical control box, minimizing interference from weak current signals. 6) System Compatibility: The entire system is designed and manufactured in Israel by Luosheng's partner, ELMO, conforming to European standards. Since all components are manufactured by the same company, there are no compatibility issues, allowing for seamless system integration. Furthermore, MAESTRO and ELMO SIMPLIQ share strong interoperability and compatibility in their internal control methods and languages, which is unmatched by control products from different companies. 7) Increased Speed: Since MAESTRO is widely used in Europe, it also contains a wealth of functions, maximizing motion control. Many factors determine system speed, including control method optimization and servo motor performance. Control method optimization largely depends on the openness of the system programming approach, and ELMO is extremely open in this regard. As long as you have a concept, you can accomplish it through MAESTRO. In other words, MAESTRO has many control modes such as PT, PVT, and ECAM, so we only need to select the function we need to achieve our desired functionality. 8) Improved Accuracy: System accuracy depends on several factors, including motor feedback accuracy and mechanical conditions. Using the ELMO system, we can analyze our system application through various methods, improving system stiffness and reducing the adverse effects of resonance. Meanwhile, due to the high-speed position loop sampling time and high-speed CAN network transmission speed of the ELMO system, our system speed can be greatly improved. For example, MAESTRO knows the running position of the servo motor in 240 microseconds (servo position loop refresh time) + 200 microseconds (CAN network PDO data transmission time), that is, it can complete the function in 400 microseconds. 9) System stability ELMO's MAESTRO uses a PC-based framework, and all internal chips use mature chips (including CPU, CAN network chip). The ELMO servo driver uses FASST (FAST AND SOFT SWITCH SWITCHTECHNOLOGY), which greatly reduces the system's heat loss, etc. IV. Conclusion 1. The equipment described in this article is a grooving and grinding equipment. The above figure shows the final product produced. When understanding the process, the final product should be studied first to determine the initial selection scheme. For example, the customer's product is a fishtail milling cutter and a drill bit. It seems like a very complex product. After discussion and research with the company's production department, the detailed production process of the milling cutter and drill bit is as follows: a. The milling cutter process is relatively simple, but the machining is coarser compared to other milling cutters, with a material diameter >1mm. The key issues in combining rotary and linear motion are the cutting edge separation and the combination of left-hand and right-hand rotation. Each cut uses PTP motion, and the angle is synthesized from the PVT curve of the Y-axis. b. Drill bits have a more complex process and require finer machining, with a material diameter <0.45mm. The smallest diameter is 0.15mm. They include single-segment and three-segment types. In a single-segment drill bit, the main groove is cut twice. After the main groove is completed, an edge cutter is needed. The edge cutter rotates at an angle to the main groove before cutting. The ligament between the edge cutter and the groove is a challenging aspect of the process. The ligament acts as the main force for drilling, equivalent to the cutting edge of a blade, and is therefore very important. Each drill bit must have a ligament, and the ligament must be parallel to the main groove. 2. After familiarizing ourselves with the process, we determined whether the existing products could meet the production requirements and selected electrical configurations based on the existing products. The customer's previous configuration was HMI + Advantech industrial PC + Advantech motion control card + 5 Dongfang stepper motors. The customer wanted the HMI program to remain unchanged and proposed a new solution using the existing products: Luosheng HMI + Luosheng ELMO Maestro + 5 Luosheng ELMO servos. Since the Maestro only has 8 output points and the driver has 2 output points per unit, totaling 10, but the customer needs 26 output points, we selected WAGO, which supports the CANopen protocol, to expand the output points. Ten input points were required, which were sufficient for the Maestro and the driver. 3. Based on the process, we redesigned the I/O on the HMI and various devices. According to the protocol between Maestro and the HMI, we redefined the buttons, numerical displays, numerical inputs and outputs on the HMI. This design will be applied in subsequent programming. 4. Distribution Panel Fabrication: Since the customer is unfamiliar with our products but familiar with their previous industrial computer wiring methods, we need to fabricate the distribution panel ourselves. Wiring is done according to the pre-planned input/output points on each device. It's important to maintain consistency with the previous industrial computer wiring methods as much as possible. Place the origin switch on each driver; for easier programming and faster response, place the other inputs/outputs on the Maestro and WAGO expansion outputs. The wiring methods for drivers and Maestro are different, requiring different resistor values. Before wiring, test the 24V power supply to the output and input separately. If the input can be detected or the output can be controlled, the wiring is correct, and then complete the full wiring work. [align=center]Figure 3: Processed Product Result[/align] 5. Debugging and Acceptance: This is the most critical stage in project development. The reliability of the program is tested at this stage. Similar to programming, it starts with simple manual operation, then no-load milling cutter operation, then no-load drill bit operation. Next comes actual milling, continuous milling, actual drill bit operation, and continuous drill bit operation. Many problems were encountered during acceptance testing, primarily related to machining processes. These are summarized below: a. The JOG process: Previously considered unimportant, the customer's experience revealed that the speed and accuracy of the JOG response are crucial to machining. JOG is used during tool setting, requiring fast response at low speeds. Without a faster response, the Y-axis is prone to colliding with the grinding wheel during tool setting, causing damage. The solution was to remove the scanning hydraulic output process during axis phase selection, ensuring fast program execution during JOG and achieving real-time response. b. The homing process, including continuous and individual homing. During the homing process after power-on, continuous homing consistently resulted in a mismatch between the Y-axis and actual movement. This was due to incorrect homing settings. After adjusting the settings, the homing process was successful. c. The emergency stop logic has also been significantly improved. Pressing the emergency stop triggers a Y-axis retraction to prevent collision with the grinding wheel. The logic for the arm and tool changer, grinding wheel stop, and cutting fluid stop are added based on customer requirements during actual operation. d. During milling, an initial error in calculating the groove angle caused an incorrect actual position of the composite curve of the X and Z axes. This manifested as an incorrect groove angle in the actual machining. The groove angle was recalculated, and the composite curve of the X and Z axes was redesigned based on the calculation results, i.e., the distance rotated by the Z axis and the distance traveled by the X axis, i.e., the correspondence of the groove length. The problem was solved. e. Parameter storage issue: Parameters are stored in real-time after machining. Due to the limited number of write cycles in Flash memory, real-time storage requires fewer cycles, storing only when needed. The storage location is added after each automatic run stops, reducing the number of storage cycles and achieving real-time storage. f. Offset change input: When changing the offset input, the input data is added to the existing data. This facilitates adjustments during machining and prevents input errors. This function is implemented by writing macro instructions on the HMI. g. In the drill bit machining process, the tool should be lifted in advance to prevent excessive cutting depth at the rear end, which can easily cause the drill bit to break during use. Therefore, adding an advance tool lifting process to the program yields good results. h. During drill bit machining, a dulling phenomenon may occur in the groove or side cutting. When monitoring the motor operation curve, it was found that the motor operation was very smooth without any pauses. After replacing the grinding wheel, the dulling phenomenon disappeared. i. Finally, our Luosheng Electrical part has been completed, and the program has been tested. However, the results were not ideal when testing 0.2mm material. Monitoring the motor curve showed no problems. We reached an agreement with the customer that the issue was either mechanical or material-related, and this was accepted by the customer.