1. MAKTAB KEJURUTERAAN JEFRI BOLKIAH
KUALA BELAIT
NEGARA BRUNEI DARUSSALAM
ASSIGNMENT 1
SESSION 2012/2014

Please Tick (  ) First Attempt: 
Re-Do:
TITLE: ENGINEERING DRAWING FUNDAMENTAL,GEOMETRICAL
CONSTRUCTION, ORTHOGRAPHIC & PICTORIAL PROJECTIONS AND
PATERN DEELOPMENT
UNIT TITLE: ENGINEERING DRAWING
NAME/ID CARD NUMBER: Abd Ammar Ar-rasyid bin Razali(01-061196)
GROUP/LEVEL: Diploma Year 1 Marine Engineering (A)
DATE GIVEN: 2013 DATE SUBMITTED:
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2. Table of Contents
Table of Contents ...........Error! Bookmark not defined.
Introduction ..................Error! Bookmark not defined.
Engineering Drawing (used in communication) ............. 2
Orthographic Projection ....................................... 5
Type of Lines used in Engineering Drawing ................. 6
Pictorial Drawing ................................................ 8
Isometric Projection .......................................... 8
Oblique Projection ............................................ 9
Perspective Projection ..................................... 11
Conclusion...................................................... 12
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3. Introduction
An engineering drawing is a type of technical drawing and as well as a
graphical language used by those concerned with the constructive arts: in the
manufacturing of machinery, structure, ships, aircraft and so on. Engineering
drawings are often referred to as “blueprints” or “blue lines”. It is used to fully
and clearly define requirements for engineered items and is usually created in
accordance with standardized conventions for layout, nomenclature,
interpretation, appearance, size and etc.
Its purpose is to accurately and unambiguously capture all the geometric
features of a product or a component. The end goal of an engineering drawing is to
convey all the required information that will allow a manufacturer to produce a
specific component. In short, student like us has not only to write the language but
also to read it. To ensure uniformity of interpretation the methods adopted for
preparation of drawings have been standardized through various standards.
Find google, introduction of engineering drawing
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4. Engineering Drawing (used in communication)
All forms of engineering and technical work require that a two dimensional surface
(paper) be used to communicate ideas and the physical description of a variety of shapes.
Here projections have been divided in to two basic categories; pictorial and multi view.
This simple division separates single view projections (oblique, perspective and isometric)
from multi view projections (orthographic). Theoretically, projections can be classified as
convergent and parallel, or divided in to three systems of projection: perspective,
oblique, and orthographic. Division of types based on whether the drawing is a one view or
multi view projection sufficiently separate projection types in to those used for
engineering working drawings (orthographic) and those used for display (architectural
rendering, technical illustrations etc.)
In short, one of the best ways to communicate one's ideas is through some form of
picture or drawing. This is especially true for the engineer. The purpose of this chapter is
to give you the basics of engineering sketching and drawing. We will treat "sketching" and
"drawing" as one. "Sketching" generally, means freehand drawing. "Drawing" usually, means
using drawing instruments, from compasses to computers to bring precision to the
drawings.
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5. Orthographic Projection
Orthographic projection is the representation of a three-dimensional component on
a flat surface (the drawing sheet) in two dimensional forms. This consists of a set of two
or more separate views of component taken from different directions, generally at right
angle to each other and arranged relative to each other in a definite way. Two methods of
Orthographic Projection are used, First-angle projection and Third-angle projection.
However, three views are shown in order to clarify internal and external detail. The views
are known as:
FRONT VIEW
TOP VIEW
SIDE VIEW (left and/or right hand view)
(And at times) BASE/SECTIONAL VIEWS
A comparisons of first angle projection and third angle projection
First angle Third angle
The plan is BELOW the front view. The plan view is ABOVE the front view.
The right-hand side view is on the left- The right-hand side view is on the right-
hand side of the front view. hand side of the front view.
The left-hand side view is on the right- The left-hand side view is on the left-hand
hand side of the front view. side of the front view.
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6. Type of Lines used in Engineering Drawing
A variety of line styles graphically represent physical objects. Types of lines include the
following:
Visible – are continuous lines used to depict edges directly visible from a particular
angle.
Hidden – are short-dashed lines that may be used to represent edges that are not
directly visible.
Center – are alternately long- and short-dashed lines that may be used to represent
the axes of circular features.
Cutting plane – are thin, medium-dashed lines, or thick alternately long- and double
short-dashed that may be used to define sections for section views.
section – are thin lines in a pattern (pattern determined by the material being "cut" or
"sectioned") used to indicate surfaces in section views resulting from "cutting." Section
lines are commonly referred to as "cross-hatching."
Phantom - (not shown) are alternately long- and double short-dashed thin lines used to
represent a feature or component that is not part of the specified part or assembly.
E.g. billet ends that may be used for testing, or the machined product that is the focus
of a tooling drawing.
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7. Lines can also be classified by a letter classification in which each line is given a
letter.
Type A lines show the outline of the feature of an object. They are the
thickest lines on a drawing and done with a pencil softer than HB.
Type B lines are dimension lines and are used for dimensioning, projecting,
extending, or leaders. A harder pencil should be used, such as a 2H.
Type C lines are used for breaks when the whole object is not shown. They are
freehand drawn and only for short breaks. 2H pencil
Type D lines are similar to Type C, except they are zigzagged and only for
longer breaks. 2H pencil
Type E lines indicate hidden outlines of internal features of an object. They
are dotted lines. 2H pencil
Type F lines are Type F[typo] lines, except they are used for drawings in
electro technology. 2H pencil
Type G lines are used for Centre lines. They are dotted lines, but a long line of
10–20 mm, then a gap, then a small line of 2 mm. 2H pencil
Type H lines are the same as Type G, except that every second long line is
thicker. They indicate the cutting plane of an object. 2H pencil
Type K lines indicate the alternate positions of an object and the line taken by
that object. They are drawn with a long line of 10–20 mm, then a small gap,
then a small line of 2 mm, then a gap, then another small line. 2H pencil.
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8. Pictorial Drawing
Every person cannot understand the orthographic projection. Its execution requires a
thorough understanding of the principles of projection and its reading requires a good
practice of constructive imagination. We can describe the shape of a job by means of
pictorial drawing also, which can be understood quite easily. Pictorial drawing is the
drawing of a picture in graphic language of engineers, to represent a real thing by means
of picture views. It shows the appearance of the object by one view only. Following three
methods of pictorial projections are commonly used in engineering drawing:
(a) Isometric projection
(b) Oblique projection
(c) Perspective projection
Isometric, Oblique and Perspective Drawing
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9. ISOMETRIC PROJECTION
A trained eye and good imagination will be able to understand the three dimensions of an
object. Several orthographic views on different planes are to be drawn to understand fully
an object. But in isometric projection, only one view on a plane is sufficient to represent
an object in its realistic appearance. Anyone can understand by looking at a view what the
job is by isometric projection.
Isometric Projection
Isometric projection is a type of pictorial projection. Isometric means equal measure. In
this isometric projection, all the plane surfaces and the edges formed of these plane
surfaces should be equally inclined to the metric plane. Metric plane is the same
horizontal plane which is used in orthographic projection.
To represent the three dimensions (length, breadth and height) of the object,
there are three axes known as ISOMETRIC AXES. To start an isometric drawing, a reference
line (horizontal line) and the three axes (X, Y Z) are drawn by taking an angle of 30° from
the reference horizontal line as drawn in Fig 7.2. Z axis is a vertical line to the horizontal
line drawn from intersection point of X and Y axes.
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10. OBLIQUE PROJECTION
Oblique projection may be illustrated in different ways, according to the choice of axes,
length of inclined side and direction of looking the side. As compared with isometric
projection, in oblique projection, one side of the object is horizontal, second side is
vertical and the third side is inclined at 30Oor 45O to the horizontal. The lengths of the
horizontal and vertical sides are equal to the actual lengths, but the length of the inclined
side is taken as three-fourth or half of the actual length.
In oblique projection, an object is placed with its front face parallel to a vertical
plane of projection and the visual rays parallel to each other pierce the plane of
projection obliquely (Oblique means inclined). The projection represents the front face of
the object in its true shape and size. The rest of the object is not projected true in its
shape and size. Both the isometric and oblique projections are the methods of
representing the object pictorially. But the oblique projection is preferable to the
isometric projection in representing the objects of circular shapes, because the front face
is in actual shape and size. It is not distorted.
Oblique Projection
O O
Third Axis of the Oblique Projection may be Inclined at 30 or 45
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11. Inclination of Inclined Axis Oblique projection of a cube
Perspective Projection
Perspective projection or perspective drawing is the representation of an object on
a plane surface, called the picture plane, as it would appear to the eye, when viewed
from a fixed position. It may also be defined as the figure formed on the picture plane
when visual rays from the eye to the object cut the picture plane. Perspective is mainly
used in architecture. By means of perspective, the architecture is able to show how an
object would appear when constructed.
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12. Conclusion
With my skills and what I have studied about engineering so far, I have
finished all the drawings given neat and clean. I also did research on the
internet to look for more information about engineering drawing. I used all
my engineering materials such as pencils, tee-rule, Set Square, compass,
drawing board and etc. It is a good engineering practice to review what we
have studied before, there were so many difficulties, but in the end I
encountered the problems through more research since we were given lots
of time.
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