ME 104- Computer Aided Drawing
Overview
Instructor: Assistant Professor Peyman Lahe Motlagh
Peyman.lahe@gtu.edu.tr
Introduction
Vincent Van Gogh
Starry night
Pablo Picasso
Buste de femme
4-Mar-25
ME 104 Computer Aided Drawing
2
Introduction
4-Mar-25
ME 104 Computer Aided Drawing
3
Introduction
4-Mar-25
ME 104 Computer Aided Drawing
4
Languages
Language is the use of a system of communication
which consists of a set of sounds or written
symbols which are used by the people of a particular country
or region for talking or writing.
4-Mar-25
ME 104 Computer Aided Drawing
5
4-Mar-25
ME 104 Computer Aided Drawing
6
Engineering Drawing
• It is a language!
• Consists of rules, terms and symbols!
• It is a universal language!
• An engineering drawing should be understood whoever
speaks that language!
• Meaning it must have only one interpretation!
4-Mar-25
ME 104 Computer Aided Drawing
7
Engineering Drawing
• Designers generally use drawings to represent the object which
they are designing, and to communicate the design to others.
• Drawings are useful for representing the geometrical form of the
designed object, and its appearance!
• Establish the link between design and manufacturing!
4-Mar-25
ME 104 Computer Aided Drawing
8
Engineering Drawing
4-Mar-25
ME 104 Computer Aided Drawing
9
Drawing vs Sketching
"Sketching" generally means freehand drawing. "Drawing" usually
means using drawing instruments, from compasses to computers to
bring precision to the drawings.
4-Mar-25
ME 104 Computer Aided Drawing
10
Computer Aided Drawing
4-Mar-25
ME 104 Computer Aided Drawing
11
Computer Aided Drawing
4-Mar-25
ME 104 Computer Aided Drawing
12
Computer Aided Drawing
4-Mar-25
ME 104 Computer Aided Drawing
13
Understanding the Role
of Technical Drawings
• Drawings and specifications control details of:
• Product manufacture
• Assembly
• Maintenance
• Technical drawings require use of standards to
communicate worldwide
4-Mar-25
ME 104 Computer Aided Drawing
14
Understanding the Role
of Technical Drawings
• Technical drawings can take many forms including:
• Idea or concept sketches
• Computation sketches
• Design sketches
• Layout drawings
• Part drawings
4-Mar-25
ME 104 Computer Aided Drawing
15
Understanding the Role
of Technical Drawings
• Technical drawing forms (cont.)
• Working or construction drawings
• Electrical drawings
• Installation drawings
• Assembly drawings
4-Mar-25
ME 104 Computer Aided Drawing
16
Understanding the Role
of Technical Drawings
• Technical drawings typically serve one of three
purposes:
• Visualization
• Communication
• Documentation
4-Mar-25
ME 104 Computer Aided Drawing
17
Understanding the Role
of Technical Drawings
• A wide variety of professions use technical
drawings to communicate and document designs
including:
• Civil engineering
• Mechanical engineering
• Electrical engineering
• Landscape design
• Landscape architecture
4-Mar-25
ME 104 Computer Aided Drawing
18
Understanding the Role
of Technical Drawings
• Professions that use technical drawings (cont.)
• Industrial design
• Construction engineering and technology
• Patternmaking
• Project management
• Fabrication and manufacturing
4-Mar-25
ME 104 Computer Aided Drawing
19
Artistic & Technical Drawings
• Graphic representation has developed along two
distinct lines:
• Artistic
• Technical
4-Mar-25
ME 104 Computer Aided Drawing
20
Artistic & Technical Drawings
• Before other communication methods developed,
people informed themselves through visual means
including pictures
• From earliest recorded history, drawings have been
used to represent the design of objects to be built
or constructed
4-Mar-25
ME 104 Computer Aided Drawing
21
Artistic & Technical Drawings
• Personal or cultural expression in design is often
referred to as aesthetic design
• Enhancing product development is considered
functional design
• Aesthetics and function can work hand in hand to
create appealing and functional products
4-Mar-25
ME 104 Computer Aided Drawing
22
The Design Process
• The organized and orderly approach to solving
problems is known as the design process
• The engineering design process addresses society’s
needs, desires, and problems by applying scientific
principles, experience and creativity
4-Mar-25
ME 104 Computer Aided Drawing
23
The Design Process
• Different types of technical drawings, from hand
sketches to CAD models, have specific functions in
the engineering design process
• The procedure for designing products typically
follows a process
4-Mar-25
ME 104 Computer Aided Drawing
24
The Design Process
• Stages of the design process include:
• Problem identification
• Ideation
• Refinement/analysis
• Implementation/documentation
4-Mar-25
ME 104 Computer Aided Drawing
25
The Design
Process
4-Mar-25
ME 104 Computer Aided Drawing
26
The Design Process
• Ideally, the design moves through these stages but
it may be necessary to return to a previous stage
and repeat the process
4-Mar-25
ME 104 Computer Aided Drawing
27
Concurrent Engineering
• Traditionally, design and manufacturing activities
have taken place in sequential order
• Although this is a logical approach, in practice it can
often be wasteful
• Concurrent engineering is a systematic approach
that integrates the design and manufacture of
products with the goal of optimizing the process
4-Mar-25
ME 104 Computer Aided Drawing
28
Concurrent
Engineering
4-Mar-25
ME 104 Computer Aided Drawing
29
Concurrent Engineering
• Life cycle design means that all aspects of a product
are considered simultaneously
• These aspects include:
• Design
• Development
• Production
• Distribution
• Use
• Disposal and recycling
4-Mar-25
ME 104 Computer Aided Drawing
30
Concurrent Engineering
• The basic goals of concurrent engineering are:
• Minimize product design and engineering changes
• Reduce time and cost involved in taking a product from
design concept to production then introduction to the
marketplace
• Communication between disciplines is especially
important in this process
4-Mar-25
ME 104 Computer Aided Drawing
31
Computer-Aided Design
and Product Development
• Product design often involves preparing analytical
and physical models of the product
• These models are used to study factors such as
forces, stresses, deflections, and optimal part
shape
4-Mar-25
ME 104 Computer Aided Drawing
32
Computer-Aided Design
and Product Development
• The process of constructing and studying analytical
models can be simplified by using:
• Computer-aided design (CAD)
• Computer-aided engineering (CAE)
• Computer-aided manufacturing (CAM)
4-Mar-25
ME 104 Computer Aided Drawing
33
Engineering Design Stages
• Engineering Design Stage 1
• Identify the customer and the problem
• Engineering Design Stage 2
• Generate concepts – this is often called the ideation
stage
• Engineering Design Stage 3
• Compromise solutions
4-Mar-25
ME 104 Computer Aided Drawing
34
Engineering Design Stages
• Engineering Design Stage 4
• Models and prototypes
• Parametric, constraint-based, or feature-based models use
dimensions and constraints that create “intelligent” models
• As designs are modified, the model can be updated and new
models do not have to be created
• Rapid prototyping
• Allows parts to be created quickly and directly from 3D models
4-Mar-25
ME 104 Computer Aided Drawing
35
Engineering Design Stages
• Engineering Design Stage 5
• Production or Working drawings
• The drawings show:
• Necessary views
• Material
• Dimensions
• Required tolerances
• Notes
• Other information to sufficiently describe a part for manufacture
4-Mar-25
ME 104 Computer Aided Drawing
36
Drafting Standards
• Standards are necessary to support a uniform,
effective, graphic language that can be used in
industry, manufacturing, engineering, and science
4-Mar-25
ME 104 Computer Aided Drawing
37
Drafting Standards
• Groups in the United States who provide standards
include:
• ANSI – the American National Standards Institute
• ASEE – the American Society for Engineering Education
• SAE – the Society of Automotive Engineers
• ASME – the American Society of Mechanical Engineers
4-Mar-25
ME 104 Computer Aided Drawing
38
Drafting Standards
• International standards are often defined by the
following groups:
• ISO – International Standards Organization
• ASME
• ANSI
4-Mar-25
ME 104 Computer Aided Drawing
39
Creativity Techniques
• Examine manufactured products
• Reverse engineering
• Functional decomposition
• Study the natural world
• Watch the Web
• Research patent drawings
• Design groups
4-Mar-25
ME 104 Computer Aided Drawing
40
Product Definition
• Product definition is the range of digital or hard
copy documents that specify the physical function
requirements for a product
• This can range from a 3D CAD model that specifies
manufacturing requirements within the CAD file to a
dimensioned paper sketch
4-Mar-25
ME 104 Computer Aided Drawing
41
Product Definition
4-Mar-25
ME 104 Computer Aided Drawing
42
ME 104 Computer Aided Drawing
Objectives:
• Introduce you the basic concepts and the use of engineering
drawing in the design and manufacturing field.
• Provide you the capability to read and interpret technical drawings
for manufacturing.
• Equip you with the knowledge of a CAD software to perform
drawing tasks for many engineering designs.
4-Mar-25
ME 104 Computer Aided Drawing
43
Question
What are critical features so
these LOGO blocks will fit
together in different
arrangements?
4-Mar-25
ME 104 Computer Aided Drawing
44
Perspective
4-Mar-25
ME 104 Computer Aided Drawing
45
Perspective
4-Mar-25
ME 104 Computer Aided Drawing
46
ME 104- Computer Aided Drawing
Lines and Views
Lines
4-Mar-25
ME 104 Computer Aided Drawing
48
Alphabet of Lines
4-Mar-25
ME 104 Computer Aided Drawing
49
Alphabet of Lines
4-Mar-25
ME 104 Computer Aided Drawing
50
Line of Alphabets
4-Mar-25
ME 104 Computer Aided Drawing
51
Line of Alphabets
4-Mar-25
ME 104 Computer Aided Drawing
52
Line of Alphabets
4-Mar-25
ME 104 Computer Aided Drawing
53
Line of Alphabets
4-Mar-25
ME 104 Computer Aided Drawing
54
Line of Alphabets
4-Mar-25
ME 104 Computer Aided Drawing
55
Understanding Projections
To make and interpret drawings you need to know how to create
projections and understand the standard arrangement of views.
You also need to be familiar with the geometry of solid objects and be able to
visualize a 3D object that is represented in a 2D sketch or drawing.
4-Mar-25
ME 104 Computer Aided Drawing
56
Views of Objects
The system of views is called
multiview projection. Each view
provides certain definite
information. For example, a front
view shows the true shape and size
of surfaces that are parallel to the
front of the object.
4-Mar-25
ME 104 Computer Aided Drawing
57
Multiview Projection
The system of views is called multiview projection. Each view provides certain
definite information.
4-Mar-25
ME 104 Computer Aided Drawing
58
Parallel Projection
The Six Standard Views
Any object can be viewed from six mutually perpendicular directions,
4-Mar-25
ME 104 Computer Aided Drawing
60
Revolving the Object to
Produce Views
Revolving the Object to Produce Views. You can experience
different views by revolving an object.
4-Mar-25
ME 104 Computer Aided Drawing
61
Principal Dimensions
The three principal dimensions of an object are width, height, and depth.
The front view shows only the height and
width of the object and not the depth. In
fact, any principal view of a 3D object
shows only two of the three
principal dimensions; the third is found
in an adjacent view. Height is shown in
the rear, left-side, front, and right-side
views. Width is shown in the rear, top,
front, and bottom views. Depth is
shown in the left-side, top, right-side,
and bottom views.
4-Mar-25
ME 104 Computer Aided Drawing
62