ed ass ammar 2013

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ABD. AMMAR AR-RASYID, MRE A 1 هجفري بلقي جروترأن ﻣﮐ تبMAKTAB 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: 6TH/ FEB/ 2013 DATE SUBMITTED:

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Page 1: Ed ass ammar 2013

ABD. AMMAR AR-RASYID, MRE A 1

تبمکجروترأنکبلقيهجفري 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: 6TH/ FEB/ 2013 DATE SUBMITTED:

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ABD. AMMAR AR-RASYID, MRE A 2

TABLES OF CONTENT INTRODUCTION PG.3 ENGINNEERING DRAWING PG.4 ORTHOGRAPHIC PROJECTION PG.5 TYPES OF LINES USED IN ENGINEERING DRAWING PG.6 PICTORIAL DRAWING PG.7

ISOMETRIC PROJECTION PG.8

OBLIQUE PROJECTION PG.9

PERSPECTIVE PROJECTION PG.11

CONCLUSION PG.12

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ABD. AMMAR AR-RASYID, MRE A 3

Introduction

Engineering drawing is not only the province of the draftsperson. It is the

language of the engineer. It is their means of developing and recording their

ideas, and conveying them to others. Every engineer will be using and referring to

some form of drawings almost daily. They will often be producing or directing the

preparation of drawings. Usually, they make the preliminary sketches and design

drawings in accordance with principles of engineering drawing. Because this is the

most unambiguous way of to convey and record information. It is also likely that

every engineer at sometime will be checking the work of designer drafters and

approving drawings before they are sent to manufacturing. When engineers sign

off the final approval of a drawing, they take responsibility for it.

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ABD. AMMAR AR-RASYID, MRE A 4

Engineering Drawing

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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ABD. AMMAR AR-RASYID, MRE A 5

Orthographic Projection

Orthographic projections are a way of describing what an object looks like from several

different views. Orthographics are also called engineering drawings or plan views. Using a

set of orthographics an Illustrator can easily draw the three-dimensional object from any

angle and in perspective, isometric or any number of other drawing systems. 3D modelers

often use orthographics to accurately create an object in a 3D application.

An orthographic is one way to describe a three dimensional object in two-dimensional

space. Typically an orthographic will have the top, side and front views of an object

drawn together with some kind of scale 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 right-hand side view is on the left-hand side of the front view.

The left-hand side view is on the right-hand side of the front view.

The plan view is ABOVE the front view.

The right-hand side view is on the right-hand side of the front view.

The left-hand side view is on the left-hand side of the front view.

Page 6: Ed ass ammar 2013

ABD. AMMAR AR-RASYID, MRE A 6

Type of Lines used in Engineering Drawing

A variety of line styles graphically represent physical objects. Types of lines include the

following:

Object or visible lines are used to represent the outline or contour of the

object being drawn.

Center lines are used to represent the center of round or cylindrical features,

or the symmetry of a feature

Center marks are used to represent the center points of a radius (arc) or

circle.

Hidden lines represents edges and outlines that are visible features of an

object in a particular view.

Phantom lines represent the outline of an adjacent part, show alternate

positions of a moving part, or replace repetitive details such as gear teeth and

threads.

Break lines represents an area of an object that has been removed for clarity

or convenience.

Cutting-plane lines represent an imaginary cut through a part to show a cross-

section.

Viewing-plane lines represents the direction of sight used to view particular

feature.

Section lines are used to show where material has been cut away in a section

view. A cutting-plane or break lines may used to expose the material.

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ABD. AMMAR AR-RASYID, MRE A 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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ABD. AMMAR AR-RASYID, MRE A 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. 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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ABD. AMMAR AR-RASYID, MRE A 9

ISOMETRIC PROJECTION

Isometric projection is a method for visually representing three-dimensional objects in two dimensions in technical and engineering drawings. An isometric view of an object can be obtained by choosing the viewing direction in a way that the angles between the projection of the x, y, and z axes are all the same, or 120°.

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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ABD. AMMAR AR-RASYID, MRE A 10

OBLIQUE PROJECTION

Oblique projection is a simple type of technical drawing of graphical projection used for

producing pictorial, two-dimensional images of three-dimensional objects. In an oblique

pictorial drawing, the angles displayed among the axes, as well as the foreshortening

factors (scale) are arbitrary. More precisely, any given set of three coplanar segments

originating from the same point may be construed as forming some oblique perspective of

three sides of a cube.

Oblique Projection

Third Axis of the Oblique Projection may be Inclined at 30O or 45

O

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ABD. AMMAR AR-RASYID, MRE A 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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ABD. AMMAR AR-RASYID, MRE A 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.

Reference

http://www.csee.umbc.edu/~rheingan/435/pages/res/view/view2-4.gif

http://draftingmanuals.tpub.com/14276/img/14276_304_1.jpg

http://en.wikipedia.org/wiki/Oblique_projection

http://draftingmanuals.tpub.com/14040/img/14040_38_3.jpg

http://engineerharry.files.wordpress.com/2012/05/lines.png