Engineering Drawing

Engineering Drawing

COURSE OUTLINE

Subject : Engineering Drawing
Code : DFV10032
Credit Hours : 1
Lecturer : Mohamed Fahami B. Sulaiman / Mohd Khairil Helmi
Unit: 5 units
Assessment : No Final Exam

Practical Assessment 100%:-

Practical Assesment 1 : 10 % (Theory)

Practical Assesment 2 : 20 %

Practical Assesment 3 : 20 %

Practical Assesment 4 : 20 %

Practical Assesment 5 : 20 %

Home Assignment : 10 %

Outcome: An ability to:-
1.Use the knowledge of technical drawing for engineering practice
2.Use software for engineering design

Venue: CAD Lab 2
Time:

Engineering Drawing
Introduction to Engineering Drawing

Learning Outcome

Unit 1: Introduction to Engineering Drawing

After completing this lesson student should be able to:
1. Write the meaning of Engineering drawing
2. Identify basic tools in manual drafting.
3. Read and interprete the information provided in engineering

drawing.
4. Visualize the 2D or 3D view of an object and identify their first and

third angle projection.

Engineering Drawing
Introduction to Engineering Drawing

1.1 What is engineering
drawing?

Clearly and concisely,
communicating all of the information necessary,

to transform idea or concept into reality

A drawing that communicates
an idea or design

Engineering Drawing
Introduction to Engineering Drawing

Categories of Engineering Drawing

Electrical • Circuit schematic
drawing • Circuit board layout

Electronic • electrical component and

drawing symbol

Civil • Plans for a bridge
drawing • Road layout

Mechanical • Detailed drawing of a part that

drawing needs to be machined.

Elements of Engineering Drawing

Engineering drawing are made up of graphics
language and word language.

Graphics language

Describe a shape (mainly).

Word language

Describe an exact size,
location and specification
of the object.

Elements of Engineering Drawing

Engineering Drawing

Graphics Word
language language

Geometric Projection Lettering
construction method

Line Types

Engineering Drawing

 Engineering drawing in design process

Visualise to see the problem Visualisation is the
Sketches & possible solutions ability to mentally
Geometric model picture things that do
to record initial ideas not exist

created from sketches Communication -
used for analysis the design solution
should be
communicated to
others without
ambiguity

Detail drawings to record the precise data Documentation -
3D model for production process permanent record of
the solution

8

A dimensioned technical/mechanical drawing 3-D computer model of the interior of
an office building

9

Engineering Drawing
Contain a complete information as a reference & guide to produce

Words are not the natural
language of engineers.
Drawings are their prose,
mathematics their grammar
and differential equations
their poetry.

Engineering standards

 Standards and conventions

 To ensure everybody using the same method
 Commonly used:

 ISO
 American National Standards Institute (ANSI)
 American Society of Mechanical Engineers (ASME)
 Japanese Industrial Standards (JIS)

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Engineering Drawing

Introduction to Engineering Drawing

Common Features in
Engineering drawing?

a) Geometry
b) Dimensions
c) Tolerances
d) Materials
e) Finish

1.2.Manual Drafting Instruments

Drawing table T-square Drafting set Spring bow compass

Arm type drafting machine Track type drafting machine

Engineering Drawing
Introduction to Engineering Drawing

Conventional Instruments

Proportional divider Divider Triangle/Set Square Technical Pen

Circle Template Protractor French Curves Drafting brush

1. Drawing Table

Engineering Drawing
Introduction to Engineering Drawing

Example

2. Drawing Sheets

A Series Formats
(mm)

A0 841 × 1189
A1 594 × 841
A2 420 × 594
A3 297 × 420
A4 210 × 297
A5 148 × 210
A6 105 × 148
A7 74 × 105

Engineering Drawing
Introduction to Engineering Drawing

1.3 Basic Line Types

TYPE CHARACTERISTIC LINE
Visible
are continuous lines, thick
Hidden & dark, used to depict
edges directly visible from
Center a particular angle.

are short-dashed lines,
thinner than visible, used
to represent edges that are
not directly visible

are alternately long- and
short-dashed lines used
to represent the axes of
circular features.



1.3.2 Horizontal & vertical lines
1.3.3 Angular lines

1.3.4 Parallel lines
1.3.5 Perpendicular lines

Engineering Drawing
Introduction to Engineering Drawing

1.4 Dimensioning & Tolerance

How to communicate dimensions properly

DIMENSIONS!!! A geometric characteristic the size of

which is specified such as length,angle,location,or center
distance

Type of Dimensioning
a). Parallel
b). Chain
c). Combined
d). Coordinates
e). Small Features
f). Circle
g). Radius

1.4.1 Parallel dimensioning
1.4.2 Chain dimensioning

1.4.3 Combined dimension
1.4.4 Dimensioning by coordinates

1.4.5 Dimensioning small features
1.4.6 Dimensioning circle

1.4.7 Dimensioning Radial

Dimensioning radiall

Engineering Drawing
Introduction to Engineering Drawing

Dimension Lines (DL)
Position of DL

Alignment of DL DL of Small Features

Dimensioning Angles Dimensioning Circles



Engineering Drawing
Introduction to Engineering Drawing

1.4.9 Tolerance

A maximum and minimum permissible variation
from the dimension

Example 100.00 mm
100.00 mm ± 1.0
100.00 mm ± 0.5
100.00 mm ± 0.2
100.00 mm ± 0.1
100.00 mm ± 0.05
100.00 mm ± 0.025
100.00 mm ± 0.01
100.00 mm ± 0.005
100.00 mm ± 0.001

Engineering Drawing
Introduction to Engineering Drawing

Example

QUESTION

In an AutoCAD class, MJII students were instructed to
draw a square with the length of 10mm. The maximum
and minimum permissible variations from the
dimension are from 9.90mm to 10.10mm.
Please state the tolerance for the square’s length.

1.5 Visualization

Forming an accurate mental picture on how a 3D object will look
when presented in a 2D format

Forming an accurate mental picture on how a 3D object will look
based on the information given in a 2D representation



1.6 Projection

Projection is done by extending lines of sight (called projection
line) from the eye of the observer through lines and points of an
object being viewed, to the plane of projection.

Object

Isometric
Views
Orthographic
Views

FIRST ANGLE & THIRD ANGLE PROJECTION

Symbol



Angles of Projection

 First-angle projection

 Used by many European countries
 Object is projected onto planes from the

first angle or quadrant

 Front view projected to vertical plane
 Top view projected to horizontal plane
 Left-side view projected to profile plane

Angles of Projection

TOP VIEW  Third-angle projection

 Standard for the United States
 Third quadrant is used for projection

 Front view projected to vertical
plane

 Top view projected to horizontal
plane

 Right-side view projected to
profile plane

FRONT VIEW RSIDE

Question & Answer Session

Next Lesson

Types of sketching line
Orthographic sketching
Axonometric sketching

Oblique sketching
Perspective sketching

Isometric sketches