Basic CNC

1. Presenter
Sunil SKS

2. Why CNC?
Milling Lathe

3. Why CNC?
Competition between manufacturing firms is increasingly dictated by
quality, cost, variety and Servicing.
 Achieving the highest possible efficiency in manufacturing can only
produce each one of these attributes of a successful product.

4. Why CNC?
For the parts having complex contours, that cannot be manufactured by
conventional machine tools.
For small lot production, often for even single (one off) job production,
such as for prototyping, tool manufacturing, etc.
For jobs requiring very high accuracy and repeatability.

5. Why CNC?
For jobs requiring many set ups and/or the set ups are very expensive.
The inspection cost is a significant portion of the total manufacturing
cost.

6. Why CNC?
For the parts having complex contours, that cannot be
manufactured by conventional machine tools.

7. Why CNC?
For jobs requiring very high accuracy and repeatability.

8. Why CNC?
For jobs requiring many set ups and/or the set ups are very
expensive.

9. Why CNC?
The inspection cost is a significant portion of the total
manufacturing cost.

10. Why CNC?

11. Why CNC?

12. What is CNC?
NUMERICAL CONTROL is a method of automatically operating a
manufacturing machine based on a code of letters, numbers, and special
characters.

13. What is CNC?
The program is translated into the appropriate electrical signals for
input to motors that run the machine.

14. CNC stands for Computer Numerical Control.
It is the technology of controlling a machining
operation using a computer program, which is
called Numerical Control (NC) Program.
In other words, a computer rather than a person
will directly control the machine tool.

15. Conventional CNC

16. The most important computerized machine tools
that are used extensively in the industry are:
CNC Turning
(Lathe) machine
CNC Milling
machine

19. Increased speed at which parts are produced
(mass production).
Producing the same quality for all work parts.
Better dimensional accuracy which gives exact
and correct dimensions.
Less scrap.

20.  High initial cost
 Need high qualified operator.

22. Basically there are two common
coordinate systems:
Cartesian
coordinate
system
Polar
coordinate
system

23. When dealing with 2 dimensions (2D), the two-
dimensional coordinate system is used; Figure
below

24. When dealing with three dimensions (3D), the
three dimensional coordinate system is
used; see the Figure below

25. The angle is positive if it
is measured in
counterclockwise
direction starting from
positive X-axis; Fig. 1.5-
A.

27. Locate points P1 through P4 on the
coordinate system shown in Fig. 1.4
P1 X = 80 Y = 60
P2 X = -80 Y = 20
P3 X = -50 Y = -60
P4 X = 60 Y = -70

28. How can you describe
the line given in the
figure using polar
coordinate system?

31. Universal style slant bed turning center
Front view of machine

32. Headstock
& Spindle
Universal style slant bed turning center

33. Work-holding
Device
Universal style slant bed turning center

34. Tailstock
Body
Quill
Center
Universal style slant bed turning center

35. Universal style slant bed turning center
Turret

36. Z Axis- +
Universal style slant bed turning center

37. Universal style slant bed turning center
Z Axis- +

38. Universal style slant bed turning center
Z Axis- +

39. Universal style slant bed turning center
Z Axis- +

40. Universal style slant bed turning center
Z Axis- +

41. Universal style slant bed turning center
Z Axis- +

42. Universal style slant bed turning center
Z Axis- +

43. Universal style slant bed turning center
Z Axis- +

44. Universal style slant bed turning center
Z Axis- +
Z is the length controlling axis

45. XAxis
-
+
Universal style slant bed turning center

46. XAxis
-
+
Universal style slant bed turning center

47. XAxis
-
+
Universal style slant bed turning center

48. XAxis
-
+
Universal style slant bed turning center

49. XAxis
-
+
Universal style slant bed turning center

50. XAxis
-
+
Universal style slant bed turning center

51. XAxis
-
+
Universal style slant bed turning center

52. XAxis
-
+
Universal style slant bed turning center

53. XAxis
-
+
Universal style slant bed turning center

54. XAxis
-
+
Universal style slant bed turning center

55. XAxis
-
+
Universal style slant bed turning center

56. XAxis
-
+
Universal style slant bed turning center

57. XAxis
-
+
Universal style slant bed turning center
X is the diameter controlling axis

58. XAxis
-
+
3.000
X3.0
Universal style slant bed turning center
X is DIAMETER
If you want to turn a 3.0 inch diameter…
X3.0 will be the commanding
word

59. XAxis
-
+
3.000
X3.0
X is DIAMETER
Once again:
X is always the diameter-controlling axis
Z is always the length controlling axis
Also:
X+: always gets bigger in diameter
Z+: always away from the spindle
Though some machine tool builders
reverse the polarity of the X axis

60. F25
F22.5
F17.5
20
Raw Material
Finished Part
70
30

61. EXAMPLE:
O2456;
N10 G17 G21 G40 G90 ;
N20 M06 T01;
N30 M03 S2000;
……………………..
……………………..
……………………..
PROGRAM NUMBER
BLOCK
WORD
SEQUENCE NUMBER OR
BLOCK IDENTIFICATION NUMBER
N10