on the machine, and operate the tools according to the programming. Finally, execute the machining actually Table 4-1: machining plan form for a part Machining process I Side cutti Rough Semi-finish L 2. Machining tools 3. Machining cond Feedrate [4 Tool Before the actual programming, make the machining plan for how to machine the part shown in Table 4-1 and Fig. 4-1. It includes 1)Determination of workpieces machining range 2)Method of mounting workpieces on the machine tool 3)Machining sequence in every machining process 4)Machining tools and machining Side cutting Face cutting Hole machining Fig 4-1: machining plan for a part Reference posit e Present tool position Workpiece 300 Distance to the zero point of a coor. Table Program Fig. 4-2: reference position Fig 4-3: coordinate system specified by the CNC A CNC machine tool is provided with fixed position. Normally, tool change and programming of absolute zero point as described later are performed at this position. This position is called the reference position as shown in Fig 4-2 The tool can be moved to the reference position in two ways 1)Manual reference postion return 2)A The following two coordinate systems are specified at different locations 1) Coordinate system on part drawing. The coordinate system is written on the parton the machine, and operate the tools according to the programming. Finally, execute the machining actually. Table 4-1: machining plan form for a part. Machining process 1 2 3 Machining procedure Feed cutting Side cutting Hole machining 1.Machining method： Rough Semi-finish Finish 2.Machining tools 3.Machining conditions Feedrate Cutting depth 4.Tool path Before the actual programming, make the machining plan for how to machine the part as shown in Table 4-1 and Fig. 4-1. It includes: 1) Determination of workpieces machining range. 2) Method of mounting workpieces on the machine tool. 3) Machining sequence in every machining process. 4) Machining tools and machining Fig. 4-1: machining plan for a part. Fig. 4-2: reference position Fig. 4-3: coordinate system specified by the CNC A CNC machine tool is provided with fixed position. Normally, tool change and programming of absolute zero point as described later are performed at this position. This position is called the reference position as shown in Fig 4-2. The tool can be moved to the reference position in two ways: 1) Manual reference postion return. 2) Automatic reference position return. The following two coordinate systems are specified at different locations: 1) Coordinate system on part drawing. The coordinate system is written on the part