This paper introduces the application of Delta's A-series servo controllers in the MEM300 rapid prototyping machine, the process characteristics of the MEM300 rapid prototyping machine, and the use of manual and automatic adjustment of Delta servo parameters. 1. Introduction Since the 1990s, the market environment has undergone tremendous changes. Consumer demands have become more personalized and diversified; manufacturers not only need to quickly design products that meet consumer requirements, but also need to manufacture them quickly. Therefore, a new rapid prototyping technology has gradually formed and developed rapidly. Delta servo controllers, utilizing their high performance and fast, precise positioning capabilities, have been applied and developed in the rapid positioning of the X and Y axes of rapid prototyping machines. 2. Principles of Rapid Prototyping Rapid prototyping technology (rapid prototyping, or RP for short) is an advanced manufacturing technology developed in the 1990s. RP is a key common technology serving the new product development of manufacturing enterprises, and it plays a positive role in promoting product innovation, shortening the new product development cycle, and improving product competitiveness. Since its inception, this technology has been widely used in the manufacturing industry of developed countries, giving rise to a new technological field. Rapid prototyping technology is based on the integration of computer-aided design and manufacturing technology, reverse engineering technology, layered manufacturing technology, material removal forming, and material addition forming technology. The basic process of rapid prototyping is as follows: First, design a computer three-dimensional model (digital model, CAD model) of the required part. Then, according to the process requirements, the model is discretized into a series of ordered units according to certain rules. Usually, it is discretized in the Z direction with a certain thickness (commonly referred to as layering), turning the original three-dimensional CAD model into a series of layers. Then, according to the contour information of each layer, the processing parameters are input, and the CNC code is automatically generated. Finally, the forming system forms a series of layers and automatically connects them to obtain a three-dimensional physical entity. The workflow of rapid prototyping is shown in Figure 1. 3 Process characteristics of MEM300 rapid prototyping machine (1) Brief principle. The MEM300 rapid prototyping machine uses STL format files generated by the CARK system software to convert the processing code and transmit it to the PMAC control card (Delta Tau motion control card). The PMAC control card sends two 5V open-collector pulse signals to the Delta servo controllers of the X and Y axes. The Delta servo controllers control the servo motors, and the servo motors drive the extrusion nozzles through precision ball screws to realize the process of stacking three-dimensional physical entities. (2) Features of the MEM300 rapid prototyping machine. The equipment is designed based on the principle of CNC machine tools, with good rigidity and stable operation; the X and Y axes are driven by Delta A-series servo motors, precision ball screw transmission, and precision ball linear guide rails; the unique filling path grid optimization design technology makes the surface quality of the prototype higher; the system software can realize automatic inspection and repair functions for STL format original files; the automatic wire width compensation technology ensures the accuracy of parts; the wire has good grindability after forming, which is easy to finish in the later stage; the extrusion spray nozzle has no drooling and high response; high-quality components and sensing system with alarm device, high reliability, and can run continuously for a long time; the remote wire feeding mechanism controlled by the precision micro pump booster system ensures that the wire feeding process is continuous and stable; the nozzle structure can be quickly switched, which is convenient for maintenance, repair and replacement. 4 Rapid prototyping machine with Delta servo controller 4.1 Connection between servo controller and PMAC card There are two ways to connect PMAC card and Delta servo controller: semi-closed loop connection and full closed loop connection. (1) Semi-closed loop connection: the pulse signal output by PMAC card is an open collector with 5V power supply. Delta's servo pulse signal uses an open-collector wiring method with an external power supply. 36 and 43 are the pins for the positive pulse and positive direction signals, 41 is the pin for the negative pulse signal, and 37 is the pin for the negative direction signal. Shorting 17 and 11, and shorting 45 and 9, is to energize the servo motor upon power-up. The wiring method is shown in Figure 2. [IMG=Semi-closed-loop connection]/uploadpic/THESIS/2007/11/2007111618451445647V.jpg[/IMG] Figure 2 Semi-closed-loop connection (2) Full closed-loop connection: The wiring method of the pulse signal output by the PMAC card, the pulse signal of the Delta servo, and the servo ON is the same as that of the semi-closed-loop connection; the difference is that the full closed-loop method feeds back the encoder signal of the Delta servo motor to the servo controller, and then feeds it back to the host computer PMAC card for control; where 21 is the A phase + signal, 22 is the A phase - signal, 25 is the B phase + signal, 23 is the B phase - signal, 50 is the Z phase + signal, and 24 is the Z phase - signal; the wiring method is shown in Figure 3. [IMG=Fully Closed-Loop Connection]/uploadpic/THESIS/2007/11/20071116184902974295.jpg[/IMG] Figure 3 Fully Closed-Loop Connection 4.2 Debugging of Delta Servo Controller (1) Manual Debugging: After the mechanical installation and electrical connection of the entire system are completed, first use the manual control mode of the host system or Delta servo, and set all servo parameters P0-02 to 14, so that the X and Y axes of the mechanism can move back and forth. The rotational inertia JL/JM applied by the servo on this mechanism will be displayed on the servo display screen. We use the Delta servo debugging software GAIN.EXE to input the rotational inertia JL/JM displayed by the servo and the response bandwidth BW calculated by us through debugging into the GAIN.EXE software. In the rapid prototyping machine, we tested that the rotational inertia JL/JM of the servo is 2.5 and the response bandwidth BW is 80-100. We calculated the parameters we need and manually input these parameters into the servo controller. The rapid prototyping machine can then run normally. (2) Automatic debugging: This debugging is simpler than manual. First, just like manual, the moment of inertia JL/JM: 2.5 should be tested and entered into parameter P1-37. Then, parameter P2-31 should be set to 54 and P2-32 should be set to 5. In this way, the rapid prototyping machine can run normally. Manual adjustment is much more accurate than automatic adjustment. A set of parameters most suitable for the whole mechanism can be tested through multiple processing tests. However, manual adjustment takes a long time and takes a lot of time. At the same time, in the process of mass production, the input of servo parameters is also very inconvenient. Delta A-series servos have high performance, short settling time, and wide frequency tuning parameters in rapid prototyping machine applications. Therefore, we use automatic adjustment more often in the normal application of rapid prototyping machines. (3) Parameters that need to be changed when using Delta servos in rapid prototyping machines, i.e., parameter descriptions: P0-02:14 = Driver status display; used to display the rotational inertia of the mechanism; P1-37:2.5 = Servo motor load inertia ratio; used to set the load inertia ratio of the servo motor in automatic mode; P1-44:2 = Numer of electronic gear ratio; ensures that the distance moved by the ball screw and other mechanisms driven by the servo motor is the same as the distance required by the host computer; P2-00:157 = Position control gain; mainly controls the responsiveness of the servo position loop; P2-04:2189 = Speed ​​control gain; mainly controls the responsiveness of the servo speed loop; P2-06:10 0 = Speed ​​integral compensation; controls the fixed deviation of the servo motor and mechanism, and the jitter of the entire mechanism; P2-25:2 = Resonance suppression low-pass filter; used to set the time constant of the resonance suppression low-pass filter; P2-26:51 = External interference resistance gain; used to increase the resistance to external forces and reduce overshoot during acceleration and deceleration; P2-31:54 = Automatic and simple mode setting; used to set the response bandwidth in automatic mode; P2-32:5 = Gain adjustment method; sets the servo adjustment mode to PDFF automatic mode, i.e., the load inertia ratio is fixed, and the servo response bandwidth is adjustable. 5 Conclusion Rapid prototyping machines are high-tech mechanical equipment with broad application prospects and continuous improvement. With increasingly fierce market competition, this equipment will be used by more and more enterprises, playing an increasingly important role in enterprise development and bringing huge economic benefits. At the same time, market competition for rapid prototyping machines is becoming increasingly fierce. Delta servo, with its high cost-performance ratio, has been applied to rapid prototyping machines and will certainly have a very broad development space. Proceedings of the 2nd Servo and Motion Control Forum and the 3rd Servo and Motion Control Forum