CNC Turning. Module 3: CNC Turning Machine. Academic Services PREPARED BY. January 2013

Transcription

1 CNC Turning Module 3: CNC Turning Machine PREPARED BY Academic Services January 2013 Applied Technology High Schools, 2013

2 Module 3: CNC Turning Machine Module Objectives Upon the successful completion of this module, the student will be able to: Describe the main parts of the EMCO CNC turning machine. Operate the EMCO CNC turning machine. Identify the main reference points on the EMCO CNC turning machine. Distinguish the main control keys and their functions. Run the spindle of the Emco machine to a specific speed. Reference the machine in X and Z. Select the proper mode to move the tool turret in X and Z. Set the required tool in the active position. Decrease/Increase the feed rate in a specific percentage. Module Contents Topic Page No. 1 Main parts of Turning (Lathe ) machine 3 2 Points at Turning machine 4 3 Switch the machine ON/OFF 5 4 Main Control Keys 10 5 Practical Tasks 11 6 Activities on MTS 13 2 Module 3: CNC Turning Machine

3 1. Main parts of the Turning (Lathe) machine: Fig. 3.1: Parts of the Turning machine 1. Wheel cover 8. Cross file 2. Head stock 9. Longitudinal slide 3. Three-jaws chuck 10. Tail stock 4. Chip Tray 11. Machine bed 5. Chip Guard 12. Emergency Off 6. Step motor 13. E-cabinet 7. Tool Turret 14. Key switch Module 3: CNC Turning Machine 3

4 2. Points at the CNC turning machine: Fig. 3.2: Points at the CNC turning machine Machine zero point (M) It lies in the rotary axis at the front of the spindle nose. The machine zero point is the origin of the coordinate system. It is set by the manufacturer and cannot be changed. See Fig. 3.2 Reference point (R) The reference point is a fixed point on the machine. It serves for the calibration of the measuring system. The reference point MUST be approached after each switch on of the machine to communicate the exact distance between the points (M) and (N (T)) to the control. Fig Module 3: CNC Turning Machine

5 Workpiece zero point (W): The workpiece zero point can be freely programmed by the user. By programming a workpiece zero point, the origin of the coordinate system is displaced from the machine zero point into the workpiece zero point. Fig. 3.2 Tool holding fixture (N): The tool holding fixture reference point lies on the face of the tool holder (turret) as shown in Fig Switch the machine ON / OFF: 3.1 Switch the machine ON: - Open air supply - Switch on the main switch at the E-cabinet - Turn on the PC - Launch Control Software - Open and close the chip guard door once for checking the door safety switch 3.2 Switch OFF the machine: - Terminate control software - Terminate Windows - Switch off main switch - Lock air supply Module 3: CNC Turning Machine 5

6 4. Main Control Keys: 4.1 Machine control keyboard: Fig. 3.3: Machine control keyboard of the EMCO PC-Turn Series : Skip blocks will not be executed : Test run of programs, in which the program will run while the spindle is not rotating and there is no workpiece in the clamping device. : Reset : Program stop : Program start : Manual axis direction movement : Approaching the reference point in all axes : Open / Close door : Open / Close clamping device 6 Module 3: CNC Turning Machine

7 : Swivel tool turret : Coolant/ Puff Blowing On / Off speed) : Spindle speed override (increase or decrease the spindle Feed override switch (increase or decrease the feed rate) Mode selector: Mode selector provides several operating modes : REF, MEM, EDIT, MDI, JOG, and INC mode REF: Referencing Manual referencing - Press the Z or +Z key: the slide traverses to the reference point in Z. Module 3: CNC Turning Machine 7

8 - Press the -X or +X key: the slide traverses to the reference point in X. Automatic referencing: - Select REF Mode: - Press the reference key : The slides traverse to the reference point in both axis, one after the other. MEM (Memory Mode): To run the program in automatic mode. EDIT: Allows the addition, modification, and deletion of programs. MDI: (Manual Data Input): Is used when the user wishes to manually input program commands into the system. The programs are typed directly into the system via MDI keypad. Example: To run the spindle at 1000 RPM in clockwise direction: Solution: Close the door Select MDI mode Press the [PROG] from function keys fig. 3.3 Use Data Input Keys Fig. 3.4, to write the following block: S1000 M3 (then press INPUT key) Press Start Press reset to stop the program Press POS JOG: In this mode the slides can be moved in one axis at a time by use of the Axis Direction Keys. INC (Incremental): In this mode the slides can be moved certain distances in micron. 8 Module 3: CNC Turning Machine

9 *Notes The machine is switched off by means of the main switch. It is recommended to switch off the machine only in inoperative position of the tool turret. Operation is interrupted by means of the reset key. All current machine functions are interrupted with RESET. 4.2 Function Keys: Function Keys enable the user to know the current positions of the tool, deal with programs, make the necessary setting e.g workpiece and tool settings, control program simulation,. etc. Fig. 3.3 Fig. 3.3: Function Keys 4.3 Data Input Keys: Data input keys runs several functions (numbers, address characters). Fig. 3.4 Fig. 3.4: Data Input Keys Module 3: CNC Turning Machine 9

10 5. Practical Tasks: (Before performing these tasks, the tools on the turret should be checked for any expected collision with the chuck) 5.1 Machine Task 1: Select Reference mode (door closed/chuck closed) Reference the machine in X Reference the machine in Z Open the door Close the door Open the door Open / close the chuck Select JOG mode Increase the feed rate to 110% (Use feed rate override) Decrease the feed rate to 90% Move the turret in positive Z Check the tools on the turret for any expected collision, then Rotate the turret to make tool number 5 active. Decrease the feed rate to 20% Move the turret in negative Z Increase the feed rate to 100% Move the turret in positive Z Move the turret in negative X Move the turret in positive X Switch coolant (air) ON Switch coolant OFF Select reference mode press automatic referencing button 10 Module 3: CNC Turning Machine

11 5.2 Machine Task 2: Select JOG mode Move the turret in positive Z Adjust the feed rate to 80% Move the turret in negative Z Move the turret in positive Z Move the turret in positive X Move the turret in negative X Select MDI mode (While door is closed) On (Function Keys), Press Program Use the (The data input keys) to write S1500 M3 then press INPUT Press Start program Increase the speed to 120% Decrease the speed to 80% Set speed to 1000 RPM (100%) Stop the program (Reset) Press POS Select Jog mode Move the turret in positive Z Select MDI mode (While door is closed) On (Function Keys), Press Program Write T0303, then press INPUT (Check the turret for any possible tool collision with the chuck) start the program Stop the program (Reset) Select tool no.7 to be the active tool, then press reset Press POS. Select Reference mode Reference the machine in X Reference the machine in Z Module 3: CNC Turning Machine 11

12 6. Activities on MTS: 6.1 MTS Task 1: Use MTS software to create a setup sheet and write a part program to do the finishing part shown below. Fig. 3.5: Φ 40 Φ Fig. 3.5 a) (It is advised to consider the depth of cut = 1 mm, this means the reduction of diameter from 40 to 30 mm will be done through 5 steps of cutting. The diameter will be reduced to 38, 36, 34, 32 and finally to 30 mm). Solution: Parameter Required Data The dimensions of the part before machining.(length and Diameter) Workpiece material The chucking depth Note: Specification of the zero offset values relative to; G54: IZ should be zero. 12 Module 3: CNC Turning Machine

13 Tool position number The cutting tool type and the cutting tool name Spindle speed direction of rotation feed rate Write the part program: Block No. Part program blocks N5 N10 N15 N20 N25 N30 N35 N40 N45 Module 3: CNC Turning Machine 13

14 N50 N55 N60 N65 N70 N75 N80 N85 N90 N95 N100 N105 N110 N115 N120 N Module 3: CNC Turning Machine

15 6.2 MTS Task 2: Use MTS software to create a setup sheet and write a part program to do the finishing part shown below. Fig. 3.6: Φ 40 Φ36 Φ Fig Solution: Parameter Required Data The dimensions of the part before machining. (Length and Diameter) Workpiece material The chucking depth Note: Specification of the zero offset values relative to; G54: IZ should be zero. Tool position number The cutting tool type and the cutting tool name Spindle speed direction of rotation feed rate Module 3: CNC Turning Machine 15

16 Write the part program. Block No. Part program blocks N5 N10 N15 N20 N25 N30 N35 N40 N45 N50 N55 N60 N65 N70 16 Module 3: CNC Turning Machine

17 Student's Notes: Module 3: CNC Turning Machine 17

18 References: 1. EMCO Machines Turn55 Manual 2. EMCO WinNC GE Series Fanuc 21 TB 3. MTS Software description/software version from Colchester Tornado A50 manual 18 Module 3: CNC Turning Machine