6. Specific Objectives
6
Students will able to
SO 1: List the types of controllers used in machines .
(E) (R-F).
SO 2: generate the CNC program for the given part
diagram . ( E) (Cr-C).
7. 7
Taxonomy of Objectives
Knowledge Dimension The Cognitive Process Dimension
Remember Understand Apply Analyse Evaluate Create
A. Factual Knowledge
1
B. Conceptual Knowledge
2
C. Procedural Knowledge
D. Meta Cognitive
Knowledge
12. Absolute method
Uses X, Y, and sometimes a Z-axis to establish a point
some distance from a common Reference point (origin)
Examples:
10
30
40
13. Incremental method
Point at some distance is established from its Previous
point(origin).
In this case reference point not common.
Example:
10
20
10
15. Point Establishment in Absolute
Method
points axes
Z X
p1 0 0
p2 20 0
p3 20 5
p4 10 5
p5 10 20
p6 0 20
Take p1 as reference point
16. Point Establishment in Incremental
Method
points axes
Z X
p1 0 -20
p2 20 0
p3 0 5
p4 -10 0
p5 0 15
p6 -10 0
17. Point Establishment in Incremental
Method
points axes
Z X
p1 -10 0
p2 0 15
p3 -10 0
p4 0 -20
p5 20 0
p6 0 5
18. ADDRESS CHARACTERS
O _ _ _ _ Program Name
It must start with ‘O’ followed by 4 digits 0000 to 9999
T_ _ _ _ Tool number
It must be start with ‘T’ followed by four digits whereas first two
digit represents tool number (01 to 12) and the next two digit
represents offset number (01 to 64)
A Angle
R Radius
F Feed Rate(mm/rev)
S Spindle Speed (rpm)
19. OFFSETS IN CNC
Offset - compensation of something
Geometry offset:
difference between machine’s(Tool) reference point and
work’s reference point
20. OFFSETS IN CNC
Wear offset:
• Compensation of an error (difference between observed
dimension and desired dimension)
• The value which is given to compensate the worn out of the
tool.
