Permanent Neodymium,Special Type Magnet,U-Shape Magnet,Neodymium Magnet SDM Magnetics Co., Ltd. , http://www.lg-magnets.com
MasterCAM is a kind of CAD/CAM software commonly used in China's machining industry. It provides a variety of modeling functions in the CAD part. It not only has complete 2D and 3D wireframe shapes, but also has many practical surface modeling functions. And extended standard geometry modeling capabilities. In the CAM section, MasterCAM can program the tool path (NCR) directly on the part drawing. In addition, MasterCAM also features powerful processing, extensive adaptability, scalable front and rear processing capabilities, powerful external interface functions, friendly human-machine interface, and easy to learn and understand. Due to the above characteristics, among many CAD/CAM software, MasterCAM is widely used for SMEs.
GSK990M is an economical numerical control system developed by Guangzhou CNC Equipment Factory. It has many customers in South China. In the practical teaching and practical engineering application, the author explores the application of GSK990 CNC system to realize MasterCAM automatic processing, and summarizes them as follows.
1. Adaptability analysis of MasterCAM NC program format to machine tool numerical control system
Master CAM is a highly versatile CAD/CAM software. Its automatically generated CNC machining program can adapt to many kinds of CNC machine tools, but some unique formats in the program are not directly compatible with most CNC systems, so generally Some modifications must be made to the program generated by MasterCAM (the format described above is not an index-controlled instruction system. If the instruction system of the machine is not compatible, the first post-processor must be selected to produce compatibility with the unit. CNC program). This modification is not only necessary for economical CNC milling machines, but even for CNC machining centers. The scope or content of the modifications may vary somewhat depending on the machine. If the user has been modeled in MasterCAM and has built the toolpath, go to Operation Management, click on the Post dialog in the figure, check Save NC file and Edit (Figure 1) in the box, confirm and create a new one. The NC file name automatically generates the MasterCAM NC file. In order for the format of the NC file to conform to the GSK990M requirements, it must also be processed accordingly.
As far as GSK990M is concerned, the format of the file should be changed as follows.
1. 1 Modification of the program name The GSK990M CNC system stipulates that the name of the program starts with ":", followed by a number to indicate the program name. The first line of MasterCAM's program has only the percent number %, there is no subsequent number, which does not meet the requirements of the machine system. So in the first line, replace the original percent sign % with the ":" symbol, and add a four-digit number that is not all 0 to the system to recognize the program.
1. 2 Deletion of comment statements There are several lines of English comments in front of the programs generated by MasterCAM. They are:
(PROGRAM NAME)
(DATE. . . TIME)
(FLAT ENDMILL. . . . )
The above three sections are the program name, the date (year, month, day) and time of the program generation, the type of tool used, the tool number, and the tool diameter. The contents of these three paragraphs are not related to the running track and need to be deleted. It should be noted that if more than one tool is used in the program, a note about the tool will appear once for each tool change. When you modify the program, you should find it all and delete it once.
1. 3 Individual incompatible instructions or ineffective instructions are modified to require the operator to have basic knowledge of NC programming and to be familiar with the operating system they are using. According to the situation of Guangzhou GSK990M machine tool, there are several situations that can be changed:
One is to delete or change the incompatible instructions, such as deleting the code "AO" that appears at the beginning and end of the program. Partial rewrite of the drilling command block of the deep hole drill.
The second is to delete some functional commands that are not available in economical machine tools. For example, when MasterCAM encounters multiple tool cutting, the CNC machining center has automatic tool change and tool compensation functions, while the GSK990M CNC milling machine can only use manual tool change. Therefore, The call tool command (such as T1M6), the tool forward compensation (G43) command, and the cancel tool length compensation command (G49) should be deleted. In addition, since the machine tool cannot be frequency-controlled, the spindle speed function S should also be deleted.
The third is to delete some inoperative instructions for the concise program, such as G21, G40, G49, G80, G90 and other instructions during program initialization (Note: these instructions can not be deleted if they are not initialized in the program), because these Instructions are system defaults and can be deleted.
2. Adaptability analysis of the machine function of MasterCAM NC program
2. 1 Device function restrictions on tool path The GSK990M is an economical CNC milling machine. It does not have the function of three-axis linkage. Therefore, the following functional limitations should be considered when programming the two-dimensional and three-dimensional graphics.
2. 1. 1 Lower knife mode In the cavity machining, in order to ensure the smooth progress of cutting, MasterCAM generally adopts spiral feed. This way of feeding starts from the top of the workpiece and the spiral cuts down. Due to the continuous processing method, it is easier to ensure the machining accuracy. Moreover, since there is no sudden change in speed, processing can be performed at a higher speed. However, since the GSK990M does not have the function of three-axis linkage, the spiral feed method cannot be adopted. Generally, the following feed method is used instead:
One is the vertical feed. This type of introduction requires first drilling a hole in the workpiece with a drill bit and then feeding it vertically. The vertical import method is straightforward and does not require much calculation. First drill a hole in the workpiece to avoid extreme impact. However, this type of introduction is not easy to chip.
The second is the slash feed. This method allows the tool to be fed at a certain angle to the workpiece, directly milled to a certain depth, and then milled back and forth in the plane. Because of the side edge machining, it is necessary to set the angle at which the tool cuts into the machined surface during machining.
The third is the folding line. In this way, the tool feeds the tool in a way that the line is lowered. After reaching a certain depth, the plane is horizontally milled. The fold line feed is an improved way of slash feed.
2. 1. 2 Toolpaths for some 3D graphics In MasterCAM's 3D surface machining toolpath, there are seven surface roughing methods and ten finishing methods. A considerable part of these tools involves three-axis linkage. Due to the limitation of the machine's motion function, some of these tools cannot be run on the GSK990M machine (such as Radial), and some need special parameters for the tool path. The limit can be run (such as Parallel Surface Rough Parallel). According to the author's experience in processing some typical parts, the more suitable toolpaths are rough Rough Contour and Surface Rough Pocket and Surface Finish Contour. . Therefore, machining 3D surfaces on the GSK990M machine is limited.
2. 2 Use of the coordinate system The MasterCAMNC program uses G54 as the workpiece coordinate system. In the GSK990M system, there are two ways to establish a coordinate system. One is to change the G54 coordinate system of the original MasterCAM to the G92 coordinate system. It realizes the coordinate system by setting the directional distance of the coordinate origin (program origin) to the tool starting point. set up. After the coordinate system is established, you need to increase the tool movement instructions. The G92 coordinate system is suitable for the machining of single parts.
The other one is to directly use the G54 coordinate system of MasterCAM. The G54 coordinate can be set by inputting the machine coordinate value of the origin of the coordinate system of a workpiece. The G54 coordinate system is suitable for mass production and is widely used in many SMEs.
In the mass production, in order to improve the processing efficiency, the knife can be directly lifted after processing, and the mechanical origin is not returned. At this time, the following modifications can be made to the NC program:
The original MasterCAM NC program:
(before the end of the program)
M5
G91G28Z0.
G28X0.Y0.
M30
%
After modification:
(before the end of the program)
M5
G0Z50 (safety height)
X0Y0
M30
%
The above modifications are more effective for processing larger batches of products.
3. Conclusion <br> <br> in GSK990M MasterCAM application for automatic programming process although subject to certain restrictions on some functions as an economical CNC milling machine, because of its excellent reliability and ease of operation, energy Competent for a variety of high-precision cutting, it is widely used, and the economic benefits are obvious.
Abstract: It is necessary to overcome many difficulties in running CNC software generated by CAD/CAM on economical CNC system. In this paper, a preliminary exploration of the method of automatic programming of MasterCAM using GSK990M numerical control system is carried out, and the adaptability of the machining program is analyzed. The result shows that the two-axis semi-automatic programming can be realized by using the GSK990M numerical control system.