CNC Programming “Milling”

1. CNC Programming “Milling” Module Objectives:1) To use Topmill2) To create NC programs for different milling operations

2. Milling Machine

3. G-Codes G00, G01, G02, G03, G04, G54, G90, G91, G94 and G95 Are the same as explained in module 4. New important G codes:

4. G-Codes The following G-Codes and their relative slides will be used as a reference when solving some practical tasks in this module.

5. G17, G18, and G19 Used to select the working plane • G17 XY Plane • G18 ZX Plane • G19 YZ Plane • The tool axis is vertical to the working plane

6. What Is The Correct G-code To Select The Top Surface Of The Workpiece As a Working Plane ? • G17

7. G41, G42 and G40 • With G41 / G42 the tool traverse at equal distances to the programmed contour along its path. This distance is the dimension of the radius of the cutter. • If the cutter is left to the contour this is programmed by G41 (This called cutter radius compensation left).

8. G41, G42 and G40 • If the cutter is right to the contour this is programmed by G42. • (This called cutter radius compensation right) • To cancel the radius compensation use G40

9. G70 / G71 • G70: The controller of the CNC milling machine reads the input values in imperial system (Inch) • G71: The controller of the CNC milling machine reads the input values in metric system (mm)

10. G111 • If we want to use polar coordinate system to move the tool, we need first to locate the pole (zero point of the polar coordinate system) measured from original workpiece zero point, this is done by G111. • Then write the required movement in polar system by specifying the Angle (AP) and the radius (RP). • Example: • G111 X30 Y40 Z0 • G01 RP=40 AP=60 F300

11. G147, G148, G247 and G248 Soft approach and leaving commands. • The function of soft approach and leaving serves to approach the starting point of a contour tangentially irrespective of the position of the initial point. • The function is mainly used in connection with the tool radius correction; however, it is not obligatory.

12. G147, G148, G247 and G248 • G147 Approach with straight line • G148 Leave in straight line. • G247 Approach with a quarter a circle • G248 Leave in a quarter a circle

13. Cycles

14. Cycle 81 – Drilling Cycle To make a hole in one phase

15. Cycle 81

16. Cycle 81 • To make a hole in one phase • Example: Make a hole at point X20 Y20 to a depth = 10mm

17. Cycle 81 • Solution: • G54 • S1500 M3 F120 • G00 X20 Y20 Z2 • Cycle 81 (2,0,1,-10,0) • G0 Z40 • M30 • Cycle Parameters: • Return plane absolute 2 • Reference plane absolute 0 • Safety distance 1 • Final drilling depth -10 • Depth incremental 0

18. Cycle 83 Deep Drilling Cycle

19. Cycle 83

20. Cycle 83 • Cycle 83 (2,2,,-86,,,35,4,1,1,1,1)

21. Holes 1 • To make a row of holes

22. Holes 1

23. Holes 1 - Example

24. Holes 2 To make a circle of holes

25. Holes 2

26. Holes 2 - Example

27. Pocket – (Pocket1/Pocket2)

28. Pocket 1

29. Pocket 1 - Example

30. Pocket 2

31. Pocket 2 - Example

32. Example of CNC Programming • What Must Be Done To Drill A Hole On A CNC Vertical Milling Machine? • Given That: • Absolute Positioning Mode, • Cutting Tool No. 1, Spindle Speed 1000 RPM, Clockwise Direction Of Rotation At Feed Rate 200 mm/min . • Hole Position X10, Y12, And Depth Of Hole 10 mm.

33. SolutionNC-Program %Mill_1 N005 G54 N010 G90 N015 G97 S1000 M03 N020 T1 D1 M6 N025 ………………… N030 …………………

34. Tool Home Top View Front View N025 G00 X10 Y12 Z10 Rapid To Hole Position (Above The Hole)

35. Top View Front View N030 G01 Z-10 F200 Z Axis Feed To Drill The Hole

36. Top View Front View N035 G00 Z6 Rapid Movement In Z Axis Out Of Hole

37. The NC-Program %Mill_1 N005 G54 N010 G90 N015 G97 S1000 M03 N020 T1 D1 M6 N025 G00 X10 Y12 Z10 N030 G01 Z-10 F200 N035 G00 Z6 N040 M05 N045 G00 X100 Y100 Z100 N050 M30