1. COMPUTER INTEGRATED MANUFACTURING
NUMERICAL CONTROL

3. A Definition:
Numerical Control is a system in which actions are controlled by the direct insertion of numerical data at some point. The system must automatically interpret at least some portion of the data

4. NUMERICAL DATA (NC CODE) NUMERICAL CONTROLLER MANUFACTURING OPERATOR
Drive Control
PROCESSED
PART
MACHINE UNIT

5. Types of Numerical Control
Conventional Numerical Control (NC)
Direct Numerical Control (DNC)
Computer Numerical Control (CNC)

6. Conventional Numerical Control (NC)
Data is sent to the machine tool by means of punch cards or tapes. The reader at the machine performs no calculations or interpolations.

7. Direct Numeric Control (DNC)
Is a method where a single computer controls many numerical control machine tools. These machine tools may or may not be of a similar nature

8. Computer Numerical Control (CNC)
The idea of computer numerical control is to position a computer right at the machine tool. Most, if not all machine tools that are numericaly controlled are CNC machine tools.

9. Computer Numerical Control (CNC)

10. Advantages
Reduces time for delivery of part Reduces scrap rate of material
Reduces tooling costs
Reduces layout time
Increases machine and tool life
Reduces storage problems
Less setup time
Reduces actual machining time Allows rapid design changes in part Less jigs and fixtures are needed

11. NC Programming Fundamentals
or how to put the “GO” in your G-codes

12. NC Part Programming
Linear tool motion (Milling) relative to the part

13. Example: A Milling Operation
SPINDLE
STOP !
NC CODE (Word Address Format)
N50 G00 X15 Y12.5 Z0
N55 M03
N60 G01 Z-2.5 F500 M08
N65 G01 X50
N70 G01 Y45
N75 G01 X15
N80 G01 Y12.5
N85 G00 Z0 M09
N90 G79 M04
SPINDLE
STARTED ! Z Y X
(0,0,0)

14. Basics of NC Part Programming
it is always assumed that the tool moves relative to the work piece no matter what the real situation is.
The position of the tool is described by using a Cartesian coordinate system.
If (0,0,0) position can be described by the operator, then it is called floating zero.

15. Preparatory Functions (G Codes)
Tool motion
Rapid traverse G00
Positioning command
Moves the tool at a rapid feed rate to a specific XYZ coordinate
Takes the shortest route to reach the specified point
Format
G00 Xx Yy Zz
G-codes

16. Linear Interpolation
Moves the tool from its current position to a specific XYZ coordinate at a specified feed rate
Format
G01 Xx Yy Zz ff
G-codes

17. Linear Interpolation
G-codes

18. Circular Interpolations
Moves a tool around a circular arc to a specific XYZ coordinate
Requires 5 pieces of information
Plane selection
Arc start point
Rotation direction
Arc end point
Arc center or arc radius
G-codes

19. Circular Interpolations
G02 circular interpolation clockwise around an arc G03 circular interpolation counter clockwise around an arc
G-codes

20. How You Tell Directions
The direction for G02 can be determined by rotating from the positive axes towards the negative axes. The direction for a G03 is exactly opposite
G-codes

21. Still Going in Circles basic methods Radius method
(G02,G03) Xx Yy Rr Ff (on the XY plane)
G-codes

22. Radius Method
Requires two entry parameters in the command the XYZ end point of the arc and the radius R
G02/G03 Xx Yy Zz Rr
G-codes

23. ; G90 -absolute coordinate ; M3 - spindle ON ; S - RPM G0 X0 Y0 Z10
G90 M3 S2000
; G90 -absolute coordinate
; M3 - spindle ON
; S - RPM
G0 X0 Y0 Z10
;G0- rapid movement
X10 Y5 Z2
G1 Z-2 F100
;G1- linear movement
;F- feed
X80 F200
X10 Y40 Y5
x80 Y40
x45 y45
x10 y40
x80
x80 y5
g0 z10
x0y0
M30 ; Spindle off
X45 y45
X80 y40
X5 y40
X80 y10
X5 y10
G-codes

24. G-codes

25. Quiz

26. Homework #1 - Due date: March 10th
Z=-2
Tool Diameter = 0.5 mm

27. CNC Pro-Light 1000 Machine

28. G-codes

29. Spindle On/Off
Vice Open/Close
E-stop

30. 1- Machine Home

31. 2- Reference Point

32. 3. Set position

33. 4- Run