Prepared By:
Nor Helya Iman Bt. Kamaludin
Email: helya@unimap.edu.my
Phone: 019-5443020
1. Engineering Drawing
2. Computer Aided Design
(CAD)
Definition
Design Process
Contribution CAD to Design
History
Design Format
Software
Advantage
Capability
Characteristics
Practice
Basic information include in drawing
An engineering drawing, a type of technical drawing, is created
within the technical drawing discipline, and used to fully and
clearly define requirements for engineered items.
Drawing is the universal language of engineering.
The main purpose of engineering drawings is to communicate
to other engineers, machinists, etc.
A formal and precise way of information about the shape, size,
features and precision of physical objects.
Giving all of the information needed to make the product and
being accurate in that information is the main goal.
Also known as Computer-aided drafting and
design (CADD)
Describe the use of computer program to create
design and engineering applications.
The computer process of making engineering
drawings and technical documents more closely
related to drafting.
Computer
software
CAD
Geometric
Modelling
Tools in
design
process
The integration of computer software and
geometric model to serve the design process
1. Problem definition
2. Design specification
3. Literature work
• Design starts with problems
• Requirement for a product and how it to be put together
• Search internally and externally (patent, field study etc)
4. Concept development
• Development of the concept (idea generation, decision
mapping, product research)
5. Final concept selection
• Select the final concept to develop (the best concept is
choosen)
6. Detail design
• Detailing the design, Design for Assembly (DFA) can be
applied here
7. Prototyping
• Physical model or virtual object
8. Documentation
• Engineering drawing and design report
Conceptualization
• Geometric modeling, manipulation and visualization
Analysis
• Analysis package, Finite Element Analysis (FEA),
optimization, customized program
Prototyping
• Modeling, assemblies, animation
Communication
• Engineering drawing, documentation
1970s : CAD spread widely in other sectors;
film, animation, typographic, etc
1963 : Modeled in 3D by T.E
Johnson.
• Early apllication - car and aerospace
companies
1962: SKETCHPAD system developed
by Ivan Sutherland, MIT (2D graphic).
• For the first time, designer can interact with the
computer graphically, before computer used
for numerical analysis
Computer graphics
Computer aided drawing and
drafting (CADD)
Computer aided design (CAD)
2-D Drawings
•
•
•
•
Two-dimensional
Having length and width/height dimensions
View of object appear in flat form
Often dimensioned and contain notes and text
describe features and details of the part, map or
plan.
• Identical to drawing created to manual drafting
technique.
3-D Solid Models
• Describe both the interior and exterior of a part
• Constructed differently depending on the software
• Some software allow us to produce basic solid
model using tools including solid primitive.
Point;
Line Segment;
Polygon;
Polyhedron;
Curved Surface;
Solid Object; etc
Autodesk,
Inc
AutoCAD
Autodesk Civil
3-D
Autodesk
Architectural
Desktop
SolidWorks
Corporation
SolidWorks 3-D
Design Software
Graphisoft
ArchiCAD
Design/Building
Series
1.
4.
Better work rather than traditional drafting methods that use rulers, squares,
and compasses. For example, designs can be altered without erasing and
redrawing.
2.
CAD systems also offer “zoom” features whereby a designer can magnify
certain elements of a model to facilitate inspection.
3.
Computer models are typically three dimensional and can be rotated on
any axis, enabling the designer to gain a fuller sense of the object.
CAD systems also lend to modeling cutaway drawings,
in which the internal shape of a part is revealed.
Drafting
stage
Design
stage
•
•
•
•
Increased accuracy
Increased drawing speed
Easy to revise
Availability of drawing libraries
• Built-in several analysis tools
• Better presentation (Easy to visualize)
- Pan, rotate, animate, shade, texture
1. Draw
5. Layer
concept
4. Object
snap
2. Modify
3.
Dimension
Parts or
product
information
is
completely
given
Good
engineering
drawings must
have the
following
characteristics
Information
is clearly
presented
Information
can be used in
manufacturing
of part
To create a good engineering
drawings YOU MUST do the
following tasks yourself.
•
•
•
•
Apply a proper line weight and style
Select a necessary view
Decide the appropriate place of dimensions
Select an appropriate section techniques (if
necessary)
Projected Views:
• Show as many sides as needed for completeness.
Cross Sections:
• A view that is good for showing interior features.
Table:
• Lower right corner, with material information, part
name, designer, etc
Dimension:
• These are the most important and most
complicated part of the drawing.
Dimensions tell how far
it is from one point on
an object to another
point.
Other types of
dimension:
- Radial Dimension
- Diameter Dimension
- Angular Dimensions
The most basic type is
called a Linear
Dimension because it
gives the straight-line
distance from one point
to another.
Dimensions have four
basic components:
•
•
•
•
Dimension Text
Dimension Line and Arrows
Extension Lines
Gap
Standard Code
Lines
Scaling
Standard Code
Full name
Country
Code
Thailand
มอก.
สำนักงำนมำตรฐำนผลิตภัณฑ์อตุ สำหกรรม
USA
ANSI
American National Standard Institute
Japan
JIS
Japanese Industrial Standard
UK
BS
British Standard
Australia
AS
Australian Standard
Germany
DIN
Deutsches Institut für Normung
ISO
International Standards Organization
Basic Line Types
Types of Lines
Appearance
Name according
to application
Continuous thick line
Visible line
Continuous thin line
Dimension line
Extension line
Leader line
Dash thick line
Hidden line
Chain thin line
Center line
Meaning of Lines
Visible lines represent features that can be seen in the
current view
Hidden lines represent features that can not be seen in
the current view
Center line
represents symmetry, path of motion, centers
of circles, axis of axisymmetrical parts
Dimension and Extension lines indicate the sizes and
location of features on a drawing
Example : Line conventions in engineering drawing
Line Convention
Precedence of coincide lines.
Hidden line drawing.
Center line drawing.
Precedence of Line
Order of
importance
Visible
line
Hidden
line
Center
line
Hidden Line Practice
Hidden line should join a visible line, except it
extended from the visible line.
Leave
space
Correct
Join
No !
Hidden Line Practice
Hidden line should intersect to form L and T
corners.
L
T
Correct
No !
Scaling
Scaling is used to depict objects on paper that
are either larger or smaller than the paper.
• If the object is larger than the paper, then the views of the object
are scaled Down
• If the object is smaller than the paper, then the views of the
object are scaled Up
• If the object fits on the paper, then the views are depicted at
Full scale (1:1)
A4
•Trimmed paper of a size
A0 ~ A4.
A3
•Standard sheet
size (JIS)
A2
A4
A3
A2
A1
A0
A1
210 x 297
297 x 420
420 x 594
594 x 841
841 x 1189
(Dimensions in millimeters)
A0
Orientation of drawing sheet
1. Type X (A0~A4)
c
2. Type Y (A4 only)
d
d
Drawing space
Border
lines
c
Drawing
space
c
Title block
Sheet size
A4
A3
A2
A1
A0
c (mm) d (mm)
10
25
10
25
10
25
20
25
20
25
Title block
The End…
Thank You..