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Dr. HABEEB HATTAB HABEEB
Office: BN-Block, Level-3,
Room-088
Email: hbuni61@yahoo.com
Ext. No.: 7292
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
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University TENAGA National
College Of Engineering
Mechanical Department
Academic Year – 2008-2009
Lecture Note
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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CAM
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering
Design
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering Design
 Engineering design is the partial realization of
designers concept. Today's a designer usually
cannot directly transform a concept into a
physical product. Instead, the designer conveys
his idea to others through an alternative
medium, such as an engineering drawing, and
then the manufacturing engineer or machinist
produces the design ( Fig. 2.1 ).
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Development of designer idea
Operation plan
1.
2.
3.
4.
5.
Idea
1
Engineering
Design
2
Sawing
Turning
Milling
Grinding
Inspection
Production
Design
Manufacture
3
4
( Fig. 2.1 ) Evolution of product
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued

Prior to the industrial revolution, if any one
needed to use/ farmer tool for example,
normally he will go to the blacksmith to
fabricate this tool by using conventional
methods. (why) because most tools were simple
and did not require significant accuracy.
Sometime blacksmith he don’t understand
clearly, then the farmer will use the workshop
wall as drawing paper to explain the real idea.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued
Conventional
Plough
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued

Nowadays product requirements and designs
became more complex, (Fig.2.2)
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued
(Fig. 2.2)
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued

A picture became necessary to relate the
information to others. Multiview drawings have
long been adopted by engineers as the standard
tool to represent a design. With such drawings,
design information can be passed from the
designer to others who are well trained in
reading the design drawing. The designer should
be build very good background to provide the
engineers and technicians clear designs and
completed.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued
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(Fig. 2.3)
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued
- To present the engineering drawing
there are several methods:
1
Drafting on paper with pen or pencil.
Manual drafting is tedious.
2
Computer Aided Drafting CAD/ can
improve drafting efficiency
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Engineering design: Continued
Design is stored in a computer and retrieved
1
when needed
2
Built-in symbols, templates and tools
3
Drafting is done in 2D & 3D included all
Engineering specifications
CAD
Benefits
4
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Media display is available ( Screen,
printer, plotter, LCD)
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Design Drafting

Engineering drawing is an abstract universal
language used to represent a designers idea to
others. It is the most accepted media of
communication in all phases of industrial and
engineering work.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Design Drafting

Today pictorial drawings are still employed to
supplement other design representations.
The basic engineering drawing that uses
orthographic projection provides a complete
and unambiguous representation of a part or
product . Fig. 2.4 illustrates the difference
between
perspective
and
orthographic
projections. The perspective projection drawing
in the figure uses two-point perspective.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Design Drafting
Perspective and orthographic Projections
Perspective Projection
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(Fig. 2.4)
Orthographic Projection
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Design Drafting
 Most engineering drawings use isometric
projection Fig. 2.5 . Isometric projection uses
orthographic projection to each projection
plane. The projection planes are oriented in
such away that each of axes 120˚ apart. The
reduction in length on each axes is the same.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Design Drafting
(Fig. 2.5)
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Multiview drawing
 In modern manufacturing industry, several
types of drawings are acceptable. The standard
Example: American standard (ANSI Y14), or
ISO standard (128, 129, 3098 etc,)) is still the
multiview drawing Fig. 2.6 .
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Multiview drawing
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(Fig. 2.6)
Lecturer: Dr. HABEEB ALANI
Related Documents
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 A multiview drawing usually contain two or
three views…. (Front view, Top view, Side view)
Multiview Drawing
Front view
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Top view
Side view
Lecturer: Dr. HABEEB ALANI
Related Documents
University TENAGA Nasional
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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 US & CANADA, the third-angle projection is the
system used. Fig. 2.7, In the figure the four
quadrant of the Z-Y plane is called:
I
angle
 II
angle
 III angle
 IV
angle
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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 For the third-angle
projection, always
place the object in the
3rd
quadrant
and
project the object in
the three planes .
Done by projection
the object onto:
 Frontal
 Horizontal
 Profile
….
planes
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(Fig. 2.7)
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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 The projection on the frontal X-Y plane is fixed,
and the image is called the front view. The
horizontal X-Y plane is rotated 90° clockwise on
the X-axis, the result is a top view of the
object. The profile Y-Z plane is rotated 90°
clockwise about the Y-axis, to obtain a righthand side view.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Partial View
 When a symmetrical object is drafted / Two
views are sufficient to present it. (Hence the
third view is typically omitted) Fig. 2.9 .
-Two View Drawing
of a Cap
(Fig. 2.9)
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Partial View
 A partial view can be used to substitute for one
of the two views Fig. 2.10
 Sectional and auxiliary views
are also commonly used to
present part detail. Sectional
views, like that depicted Fig.
2.10 , are extremely useful in
displaying the detailed design
of a complicated internal
configuration.
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(Fig. 2.10)
Lecturer: Dr. HABEEB ALANI
Partial View
Computer Aided Manufacturing
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 When a major surface is inclined to all three
projection planes, a translation of the picture is
seen, a circle becomes an ellipse. In that case,
an auxiliary plane that is parallel to the major
surface, like that in Fig. 2.11 , can be used to
display an undistorted view.
(Fig. 2.11)
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Dimensioning and Tolerancing
 A drawing is expected to convey a complete
description of every detail of a part.
o Dimensions convey the required size.
o Tolerances convey the required precision.
 Dimensioning basic rules of American national
Standards Institute (ANSI) as following:
o Show enough dimensions.
o State each dimension clearly.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Dimensioning and Tolerancing Cont…….
o Show the dimensions between points, lines, or
surfaces.
o Select
and
arrange
dimensions
to
avoid
accumulations of tolerances.
o Show each dimension only ones.
o Specify the dimensions, In order to provide
materials, parts, gauges etc… marks and labels.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Dimensioning and Tolerancing Cont…….
Drawing information very important for who will
use or read the drawing which affect to choice
of the following:
•
Processes.
•
Fixtures.
• Machine required.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Dimensioning and Tolerancing Cont…….
Computer Aided Manufacturing
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- Dimensioning of circle use either dia. added to
the end of the dimension value or the symbol ø
added in front of the dimension value. For the
specification of a radius an (R) is added in front
of the dimension value. :
Example ---
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Lecturer: Dr. HABEEB ALANI
Dimensioning
Computer Aided Manufacturing
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Main features of basic dimension:
o Two extension lines.
o Dimension line.
Dimension line
o Dimension value.
Dimension value
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Extension lines
Lecturer: Dr. HABEEB ALANI
Dimensioning
Computer Aided Manufacturing
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Basic rules of dimensioning:
• Dimensions should be unambiguous and
clearly.
• Dimensions should be complete, with none
missing.
• There should be no redundancy; each
dimension should be shown only once.
Example ---
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Computer Aided Manufacturing
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Dimension elements….
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Dimensions are used
to show an object’s:
1.
Overall: Width
Depth
Height
2.
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The actual size of
features (rounds,
fillets, holes, arcs,
etc.)
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
3.
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And where features are located such
as centers, angles, etc.
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Computer Aided Manufacturing
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Dimensions should be
stacked in a “broken
chain” format.
“Breaking the Chain” refers to leaving out one dimension as shown
above so that manufacturing tolerances are maintained.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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-As a general rule…Stay off the object as much as possible.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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-Extension lines can be shared and even
broken to clarify crowded dimensions.
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Computer Aided Manufacturing
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-Some features are dimensioned
from their center lines.
-The center line may also be
used as an extension line.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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- Leader with dimension for one
hole used to show all cylinders
(holes).
- The leader should always be
placed to penetrate the center
of all round features.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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Features such as counterbores,
countersinks and spot faces are
all dimensioned using a leader.
Note: Each of these features has
a special dimensioning symbol
that can be used to show:
a. Diameter
b. Shape
c. Depth
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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- Arcs are always
dimensioned as a
radius. Full circles
are dimensioned
showing their
diameter value.
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Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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- When dimensioning a
part, always start with the
inner-most dimensions
and work to the outermost values.
Remember:
Dimensions are used to
show both the size and
location of features.
University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
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- Always dimension features
clear.
- Drawing lines clear
Remember….
NEVER, NEVER, NEVER
dimension to hidden lines!
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Lecturer: Dr. HABEEB ALANI
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University TENAGA Nasional
Lecturer: Dr. HABEEB ALANI