电子教案统一模板[数控]Unit6.ppt

Unit 6 Part Programming ;6.1 Lesson 11 Manual Part Programming ; In manual part programming, the machining instructions are recorded on a document, called a part-program manuscript (Table 6-1)by the part programmer. The manuscript is essentially an ordered list of program blocks． Because a part program records a sequence of tool motions and operations to produce the final part geometry, one must prepare a process plan with setups and fixtures before writing the program. The work-piece location and orientation, features (holes, slots, pockets) to be machined, tools and cutting parameters used need to be determined. We will use an example to illustrate how a part is programmed. ;6.2 Lesson 12 Example of Manual Part Programming ; ? Mill the slot with a 3/4in. four-flute flat end mill made of carbide. From the Machinability Date Handbook, the recommended feed is 0.005 in/tooth/r and the recommended cutting speed is 620 fpm. ? Drill two holes with a 0.75in. diameter twist drill．Use 0.18ipr feed and 100fpm speed． Figure 6-2 shows the setup，fixturing，and cutter path. All dimensions in inches. All tolerance A?0.001 inch. The program for the example part is shown in Table 6-2. ;6.3 Reading Materials 11 Format of Programming Language ; It is important to mention that there are different programming language “dialects”. Each CNC controller is designed to accept a particular dialect. Thus, the format that works on one controller may have to be slightly changed when running it on another controller. It would be impractical and most likely impossible to describe all the different codes for each controller. Thus, in this text we will give the most general coding pattern that can be followed for any type of programming application. Point-to-point as well as contouring programs will be written for a CNC machine with a Fanuc controller. ; Many of the same commands can be used on other controllers but some may not.