ge8152 - engineering graphics · 2018-01-30 · ge8152 - engineering graphics mr.s.gokul (asst....

GE8152 - ENGINEERING GRAPHICS

Mr.S.Gokul (Asst. Prof/Mech)

Sri Eshwar College of Engineering

ANNA UNIVERSITY, CHENNAI (REGULATION

B.E SEMESTER–I

Lecture Tutorial Practical Marks Credits Total Hours

2 0 3 100 4 90

Syllabus Frame

2

• PLANE CURVES AND FREE HAND SKETCHINGUnit 1

• PROJECTION OF POINTS, LINES AND PLANE SURFACESUnit 2

• PROJECTION OF SOLIDSUnit 3

• PROJECTION OF SECTIONED SOLIDS AND DEVELOPMENT OF SURFACESUnit 4

• ISOMETRIC AND PERSPECTIVE PROJECTIONSUnit 5

Engineering Graphics

1. Engineering Curves

2. Free hand sketching of

Objects

1. Projection of Points

2. Projection of Lines

3. Projection of Planes

Projection of simple

solids like, prism,

pyramid.,1. Section of Solids

2. Development of

Solids1. Isometric projection

2. Perspective

projection

3

TEXT BOOKS

Natrajan K.V., ―A text book of EngineeringGraphics‖, Dhanalakshmi Publishers, Chennai,2009.

REFERENCES

Venugopal K. and Prabhu Raja V., “EngineeringGraphics”, New Age, International (P) Limited, 2008.

Kottiswaran N., “Engineering Graphics”, Sri BalajiPublications, 2011.

Saravanan.M, Arockia Jaswin.M and Bensam Raj J.,“Engineering Graphics”,Tri Sea Publications.


COURSE PLAN4

Title of the program: B.E

Course title: ENGINEERING GRAPHICS Sem: I

Course code: GE 8152 Total hours: 90

Unit No. Unit Title Time

1 PLANE CURVES AND FREE HAND SKETCHING 19

2 PROJECTION OF POINTS, LINES AND PLANE

SURFACES17

3 PROJECTION OF SOLIDS 16

4 PROJECTION OF SECTIONED SOLIDS AND

DEVELOPMENT OF SURFACES16

5 ISOMETRIC AND PERSPECTIVE PROJECTIONS 17

Revision 5

Total 90Engineering Graphics

Content of the Presentation

Introduction to Engineering Graphics

Standards (BIS)

Drawing Instruments

Lettering

Line types

Dimensioning

Projection Methods

Quadrant system

Introduction to all the units

5


INTRODUCTION TO

ENGINEERING GRAPHICS

Drawing vs. Engineering Drawing

Drawing

Describing any object/ information

diagrammatically

Engineering Drawing

Graphical means of expression of technical details

without the barrier of a language.

Universal language for engineers

7


Drawing vs. Engineering Drawing Cont.,

Graphical representation of an object – Drawing

Engineering drawing – A drawing of an object that

contains all information

- like actual shape, accurate size, manufacturing

methods, etc., required for its construction.

- No construction / manufacturing of any (man -made)

engineering objects is possible without engineering

drawing.

8


What will you learn in this course?

You will learn - How industry communicates

technical information.

Visualization – the ability to mentally control visual

information.

Graphics theory – geometry and projection

techniques.

Standards – set of rules that govern how parts are

made and technical drawings are represented.

9


What will you learn in this course? Cont.,

Conventions – commonly accepted practices and

methods used for technical drawings.

Tools – devices used to create technical drawings

and models.

Applications – the various uses for technical

drawings.

10


Engineering drawing is completely different from artistic

drawing, which are used to express aesthetic,

philosophical, and abstract ideas.

Computer has a major impact on the methods used to

design and create technical drawings.

Design and drafting on computer are cheap and less

time consuming.

11


Engineering Drawing

Manual Drawing

CADD

STANDARDS

ISO International Standards Organization

ANSI American National Standard InstituteUSA

JIS Japanese Industrial StandardJapan

BS British StandardUK

AS Australian StandardAustralia

Deutsches Institute for NormungDINGermany

Country Code Full name

Bureau of Indian StandardsBISIndia

Standard Code

13 Engineering Graphics

BIS standards


14

BIS Code Topics

IS 10711:2001 Size and Layout of Drawing

sheets

IS 10714:1983 Line Types and Uses

IS 9609:2001 Lettering

IS 15021:2001 Projection Methods

IS 11669:1986 Dimensioning

DRAWING INSTRUMENTS

Instruments required for drawing

Drawing board

Drawing sheet [A3 Size]

Mini-drafter / T- square

Instrument box (Compass, Divider, Protractor etc.,)

Drawing pencils [H, 2H, HB]

Scales, Sharpener, Eraser

Drawing clip / pin / adhesive tape

16


1.Drawing Board

17


2.Drawing Sheets

18


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

Drawing Sheets cont.,

19



A0 841 × 1189

A1 594 × 841

A2 420 × 594

A3 297 × 420

A4 210 × 297

A5 148 × 210

A6 105 × 148

A7 74 × 105

Drawing space Drawing

spaceTitle block

d

d

c

c

cBorder

lines

1. Type X (A0~A4) 2. Type Y (A4 only)

Orientation of drawing sheet

Title block

Sheet size c (min) d (min)

A4 10 25

A3 10 20

A2 10 25

A1 20 25

A0 20 2520 Engineering Graphics

A3 Drawing sheet - Dimensions

21


3. Mini –Drafter and T-Square

22


Drawing Board with Drafter and Sheet

23


4. Instrument Box

24


5.Drawing Pencils

Wooden pencils – are graded and designated by numbers

and letters

Mechanical clutch pencils – Not allowed

7B, 6B, 5B, 4B, 3B, 2B, B - in decreasing order of softness and

blackness

HB to F – Medium grade

H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H – increasing order of

hardness.

Drawings are done using 2H pencils and finished with H

and HB pencils – to be practiced in this course.

25


Grades and designation of wooden pencils

26


Grades and designation of wooden pencils

27


6.Scales, Sharpener, Eraser

28


7.Drawing clip / pin / adhesive tape

29


DRAWING SCALES

Drawing Scales

Scale is the ratio of the linear dimension of an element

of an object shown in the drawing to the real linear

dimension of the same element of the object.

Size in drawing Actual size

Length, size

:


Drawing Scales

Designation of a scale consists of the word “SCALE”

followed by the indication of its ratio, as follow

SCALE 1:1 for full size

SCALE X:1 for enlargement scales (X > 1)

SCALE 1:X for reduction scales (X > 1)

Dimension numbers shown in the drawing are correspond

to “true size” of the object and they are independent of

the scale used in creating that drawing.


LINE TYPES

Line types

34


Line types cont.,

35


DIMENSIONING

Lines used in Dimensioning

Dimensioning requires the use of

Dimension lines

Extension lines

Leader lines

All three line types are drawn thin so that they

will not be confused with visible lines.

37


Dimension Line

Dimension line: A line terminated by

arrowheads, which indicates the direction and

extent of a dimension.

38


Extension Line

Extension line: An extension line is a thin solid

line that extends from a point on the drawing to

which the dimension refers.

Long extension

lines should be

avoided.

39


Leader Line

Leader Line: A straight inclined thin solid line

that is usually terminated by an arrowhead.

40


Leader Line

Leaders may be terminated:

with an arrow, if it ends on the outline of an

object.

41


Leader Line


with a dot if it ends within the outline of an

object.

42


Leader Line


without an arrowhead or dot, if it ends within the

outline of an object.

43


Arrow heads

Arrowheads are used as terminators on dimension lines.

The standard size ratio for all arrowheads on mechanical

drawings is 3:1 (length to width).

200

R 8.5

1st 2nd 3rd 4th

Of the four different arrowhead types that are authorized by the

national standard, ASME Y14.2M – 1994, a filled arrowhead is

the highest preference.

44


Arrowheads

Arrowheads are drawn between the extension

lines if possible. If space is limited, they may

be drawn on the outside.

45


Exercise

List the dimensioning mistakes and then

dimension the object correctly.

46


What are the 6 dimensioning mistakes?

1) Spacing

6) Missing dim. (ɸ of hole)

3 & 4) Text

5) No Gap

2) Don’t dim. inside the object.

Correctly Dimensioned

LETTERING

Lettering

Lettering – Writing of titles, sub-titles, dimensions, scales

and other details on a drawing

Essential features of lettering – legibility, uniformity, ease,

rapidity, and suitability for microfilming/ photocopying/any

other photographic processes

No ornamental and embellishing style of letter

Plain letters and numerals which are clearly distinguishable

from each other in order to avoid any confusion even in

case of slight mutilations

51


Basic Strokes

Straight Slanted CurvedHorizontal

1 1 2

3

Examples : Application of basic stroke

“I” letter “A” letter 1

2

3

4 5

6

“B” letter

52


Lettering cont.,

53


Stroke Sequence

I L T

54


V X W

Stroke Sequence

55


O Q G

Stroke Sequence

56


68

0

Stroke Sequence

S 357


Stroke Sequence

j y f

r

t


Stroke Sequence

c o a b

d p q e


Leave the space between words equal to the space

requires for writing a letter “O”.

Example

Sentence Composition

ALL DIMENSIONS ARE IN

MILLIMETERS

O O O

OUNLESS

OTHERWISE SPECIFIED.O


PROJECTION METHODS

Line of sight is an imaginary ray of light between an

observer’s eye and an object.

Line of sight

Parallel projection

Line of sight

Perspective projection

There are 2 types of LOS : parallel convergeand


PROJECTION METHOD

Perspective

Oblique Orthographic

Axonometric Multiview

Parallel

63


PROJECTION THEORY

The projection theory is based on two variables:

1) Line of sight

2) Plane of projection (image plane or picture plane)

The projection theory is used to graphically represent

3-D objects on 2-D media (paper, computer screen).


Plane of projection is an imaginary flat plane which

the image is created.

The image is produced by connecting the points where

the LOS pierce the projection plane.

Parallel projection Perspective projection

Plane of projection Plane of projection


Disadvantage of

Perspective Projection

Perspective projection is not

used by engineer for manu-

facturing of parts, because

1) It is difficult to create.

2) It does not reveal exact

shape and size.Width is distorted

66


QUADRANT SYSTEM

X

Y

1ST Quad.2nd Quad.

3rd Quad. 4th Quad.

X Y

VP

HP

Observer

THIS QUADRANT PATTERN,

IF OBSERVED ALONG X-Y LINE ( IN RED ARROW DIRECTION)

WILL EXACTLY APPEAR AS SHOWN ON RIGHT SIDE AND HENCE,

IT IS FURTHER USED TO UNDERSTAND ILLUSTRATION PROPERLLY.68 Engineering Graphics

First angle vs. Third angle Projection

First angle Projection Third angle Projection

Object placed in FQ is above

HP and in front of VP

Object placed in TQ is below

HP and behind of VP

Front view is draw above

reference line

Front view is draw below

reference line

Top view is arranged below FV Top view is arranged above FV

Left side view is on the right

side of FV and Right view is on

the left side of FV

Left side view is on the left side

of FV and Right view is on the

right side of FV

Symbol Symbol


69

INTRODUCTION TO ALL THE UNITS

PLANE CURVES AND FREE HAND

SKETCHING

Unit 171



SKETCHING

Engineering Curves

Ellipse

Parabola

Hyperbola

Special Curves

Cycloids

Epicycloid

Hypocycloid

Involutes


72


SKETCHING


73

Free hand

sketching

PROJECTION OF POINTS, LINES

AND PLANE SURFACES

Unit II74


HP

VP

a’

a

A

POINT A IN

1ST QUADRANT

OBSERVER

VP

HP

POINT A IN

2ND QUADRANT

OBSERVER

a’

a

A

OBSERVER

a

a’

POINT A IN

3RD QUADRANT

HP

VP

A

OBSERVER

a

a’POINT A IN

4TH QUADRANT

HP

VP

A

Point A is

Placed In

different

quadrants

and it’s Fv & Tv

are brought in

same plane for

Observer to see

clearly. Fv is visible as

it is a view on

VP. But as Tv is

is a view on Hp,

it is rotated

downward 900,

In clockwise

direction.The

In front part of

Hp comes below

xy line and the

part behind Vp

comes above.

Observe and

note the

process.

PROJECTION OF POINTS75 Engineering Graphics

A

a

a’A

a

a’

Aa

a’

X

Y

X

Y

X

Y

For TvFor Tv

For Tv

POINT A ABOVE HP

& INFRONT OF VP

POINT A IN HP

& INFRONT OF VPPOINT A ABOVE HP

& IN VP

PROJECTIONS OF A POINT IN FIRST QUADRANT.

PICTORIAL

PRESENTATIONPICTORIAL

PRESENTATION

ORTHOGRAPHIC PRESENTATIONS

OF ALL ABOVE CASES.

X Y

a

a’

VP

HP

X Y

a’

VP

HP

a X Y

a

VP

HP

a’

Fv above xy,

Tv below xy.

Fv above xy,

Tv on xy.

Fv on xy,

Tv below xy.


X

Y

X

Y

b’

a’

b

a

a b

a’

b’

B

A

TV

FV

A

B

X Y

H.P.

V.P.a’

b’

a b

Fv

Tv

X Y

H.P.

V.P.

a b

a’ b’Fv

Tv

For Tv

For Tv

Note:

Fv is a vertical line

Showing True Length

&

Tv is a point.

Note:

Fv & Tv both are

// to xy

&

both show T. L.

1.

2.

A Line

perpendicular

to Hp

&

// to Vp

A Line

// to Hp

&

// to Vp

Orthographic Pattern

Orthographic Pattern

(Pictorial Presentation)

(Pictorial Presentation)

PROJECTION OF LINES77 Engineering Graphics

PROJECTION OF POINTS, LINES AND

PLANE SURFACES

PROJECTION OF PLANE SURFACES


78

PROJECTION OF SOLIDS

Unit III79


PROJECTION OF SOLIDS


80

PROJECTION OF SECTIONED

SOLIDS AND DEVELOPMENT OF

SURFACES

Unit IV81


SECTION OF SOLIDS


82

DEVELOPMENT OF SOLIDS


83

ISOMETRIC AND PERSPECTIVE

PROJECTIONS

Unit V84


ISOMETRIC PROJECTIONS


85

PERSPECTIVE PROJECTIONS


86

Engineering Graphics87

Thank You

Mr.S.Gokul/Assistant Professor/Department of Mechanical Engineering


Department of Mechanical Engineering

Unit

No.

Topics Page

No.

1 Plane Curves and Free Hand Sketching …. 10

Engineering Curves: Ellipse, Parabola & Hyperbola 10

Construction of Cycloid 10

Construction of Involutes 10

Scale : Diagonal and Vernier scales 10

Free Hand Sketching 11

Plane Curves & Free Hand Sketching –Assignment 6 12

2 Projection of Points, Lines and Plane

Surfaces ………………………………………………... 2

Orthographic Projection of Points 2

Orthographic Projection of Straight Lines 2

Projection of Straight Lines – Assignment 1 3

Orthographic Projection of Planes 3

Orthographic Projection of Planes – Assignment 2 4

3 Projection of Solid …………………………………. 4

Orthographic Projection of Solids 4

Truncated Solids 6

Orthographic Projection of Solids – Assignment 3 5

4 Projection of Sectioned Solids and

Development of Surfaces ……………………… 5

Section of Solids 5

Development of Surface 6

Sectioned Solids & Development of Surfaces –

Assignment 4

7

5 Isometric and Perspective Projections ….. 7

Isometric Projection 7

Perspective Projection 8

Isometric & Perspective Projections –

Assignment 5

9

GE8152 - ENGINEERING GRAPHICS OBJECTIVES:

To develop in students, graphic skills for communication of concepts, ideas and design of Engineering products.

To expose them to existing national standards related to technical drawings. CONCEPTS AND CONVENTIONS (Not for Examination)

Importance of graphics in engineering applications – Use of drafting instruments – BIS conventions and

specifications – Size, layout and folding of drawing sheets – Lettering and dimensioning.

UNIT I PLANE CURVES AND FREE HAND SKETCHING

Basic Geometrical constructions, Curves used in engineering practices: Conics – Construction of ellipse,

parabola and hyperbola by eccentricity method – Construction of cycloid – construction of involutes of

square and circle – Drawing of tangents and normal to the above curves, Scales: Construction of Diagonal

and Vernier scales. Visualization concepts and Free Hand sketching: Visualization principles –

Representation of Three Dimensional objects – Layout of views- Free hand sketching of multiple views from

pictorial views of objects

UNIT II PROJECTION OF POINTS, LINES AND PLANE SURFACES

Orthographic projection- principles-Principal planes-First angle projection-projection of points. Projection

of straight lines (only First angle projections) inclined to both the principal planes - Determination of true

lengths and true inclinations by rotating line method and traces Projection of planes (polygonal and

circular surfaces) inclined to both the principal planes by rotating object method

UNIT III PROJECTION OF SOLIDS

Projection of simple solids like prisms, pyramids, cylinder, cone and truncated solids when the axis is

inclined to one of the principal planes by rotating object method.

UNIT IV PROJECTION OF SECTIONED SOLIDS AND DEVELOPMENT OF SURFACES

Sectioning of above solids in simple vertical position when the cutting plane is inclined to the one of the

principal planes and perpendicular to the other – obtaining true shape of section. Development of lateral

surfaces of simple and sectioned solids – Prisms, pyramids cylinders and cones.

UNIT V ISOMETRIC AND PERSPECTIVE PROJECTIONS

Principles of isometric projection – isometric scale –Isometric projections of simple solids and truncated

solids - Prisms, pyramids, cylinders, cones- combination of two solid objects in simple vertical positions.

Perspective projection of simple solids-Prisms, pyramids and cylinders by visual ray method.

Mr.S.Gokul/Assistant Professor/Department of Mechanical Engineering

Orthographic Projection of Points

1. Mark the projections of the following points on a common

reference line.

Point P, 50 mm behind the VP and 15 mm above the HP.

Point Q, 40 mm below the HP and in the VP.

Point R, 40 mm in front of the VP and 30 mm above the HP.

Point S, 30 mm in front of the VP and 50 mm below the HP.

Point T, 35 mm behind the VP and 20 mm below the HP.

2. From the figure below, determine the position of the Points

with reference to the projection planes.

Orthographic Projection of Straight Lines

1. One end P of a line PQ 70 mm long is 35 mm in front of V.P. and 25

mm above H.P. the line is inclined at 400

to the H.P. and 300

to the V.P.

Draw the projections of PQ and find its vertical & Horizontal trace

2. A straight line 70 mm long has one end 15 mm in front of V.P. and 50

mm above H.P. while the other end is 35 mm in front of V.P. and 20

mm above HP. Draw the plan and elevation of the line. Determine its

traces (V.T, H.T)

3. A line AB 70 mm long has its end B 25 mm above H.P. and 30 mm in

front of V.P. The end A is 55 mm above H.P and 55 mm in front of V.P.

Draw its projections and finds its inclinations with V.P. and H.P.

4. A line AB 60 mm long has its end A 30 mm above H.P. and 25 mm in

front of V.P. The top view and front view has a length of 40 mm and

55 mm respectively. Draw its projections.

5. End A of a line AB is 15 mm above H.P. and 20 mm in front of V.P. The

other end is 50 mm above H.P. and 65 mm in front of V.P. The

distance between the end projectors is 50 mm. Draw the projection

and find the true inclination and true length by rotating plane

method.

6. The distance between the end projectors passing through the end

point is 50 mm. The end A is 20 mm above H.P. and 15 mm in front of

V.P. The end B is 45 mm in front of V.P. The line AB is 65 mm long in

the front view. Draw the projections. Find the true inclinations and

locate the traces

7. Front view of a line AB is 500

inclined to XY line and measures 55 mm

long while its top view is 600

inclined to XY line. If end A is 10 mm

above HP and 15 mm in front of VP, draw its projections, find its true

length and inclinations of the line with HP and VP.

8. The mid-point M of a line AB is 60 mm above HP and 50 mm in front

of VP. The line measures 80 mm long and inclined at an angle of 300

to

HP and 450

to VP. Draw its projections.

UNIT II - PROJECTION OF POINTS, LINES AND PLANE SURFACES

Projection of point

Projection of straight lines inclined to both the principal planes

by rotating line method and traces

Projection of planes (polygonal and circular surfaces) inclined

to both the principal planes by rotating object method

GE 8152 – Engineering Graphics

Department of Mechanical Engineering, Sri Eshwar College of Engg 3/12 /12

9. A magician performs the trick of a floating stick. As seen by a person

sitting right in front, as per the orthographic projection rules, the

stick has its ends 0.2 and 0.6 m above the floor and appears to be

inclined at 300

to the floor. The same two ends are found to be 0.1 m

and 0.7 m respectively in front of the screen arranged behind the

stick. Adopting a suitable scale, draw the projections of the stick.

Also, find the true length of the stick and its true angles of

inclinations with the floor and the vertical screen.

10. A line PQ is inclined at 350

to VP has its ends 25mm and 55mm above

the HP. The length of the front view is 60 mm and its VT is 15mm

above HP. Determine the true length of PQ, its inclination with HP and

its HT.

Assignment 1: Orthographic Projection of Straight Lines

L1. A line AB 75 mm long has one of its ends 60 mm in front of VP and 20

mm above HP, the other end is 20 mm in front of VP and is above HP.

The top view of the line is 55 mm long. Draw the front view.

L2. A line measuring 80 mm long has one of its ends 60 mm above HP and

20 mm in front of VP. The other end is 15 mm above HP and in front

of VP. The front view of the line is 60 mm long. Draw the top view.

L3. A line AB has its end A 15 mm above HP and 20 mm in front of VP. The

end B is 60 mm above HP and the line is inclined at 300

to HP. The

distance between the end projectors of the line is 55 mm. Draw the

projections and find its inclinations with VP. Determine its V.T & H.T

L4. The top view of a 75mm long line AB measures 65mm, while the

length of its front view is 50mm. It’s one end A is in the HP and

122mm in front of the V.P. Draw the projections of AB and determine

its inclinations with the H.P. and the V.P.

L5. The projections of a line measure 80 mm in the top view and 70 mm

in the front view. The mid-point of the line is 45 mm in front of VP

and 35 mm above HP. One end is 10 mm in front of VP and nearer to

it. Draw the projections. Find true length and true inclinations with

reference planes.

Orthographic Projection of Planes / Sheet / Lamina / Plate

1. A square lamina of 50 mm side rests on one of the corners on the H.P.

The diagonal through that corner makes 300

to the V.P. The side

containing this corner makes equal inclinations with H.P. The surface

of the lamina makes 450

to the H.P. Draw it’s projections.

2. A hexagonal plate of size 25 mm rests on HP on one of the sides

inclined at 450

to VP. The surface of the plate makes an angle of 300

with HP. Draw the front view and top view of the plate.

3. A thin rectangular plate of sides 60 mm x 30 mm has its shorter side

in VP and inclined at 300

to HP. Project its top view when its front view

is a square of 30 mm long sides.

4. A hexagonal lamina of 20 mm side rests on one of its corners on the

HP. The diagonal passing through this corner is inclined at 450

to the

HP. The lamina is then rotated through 900

such that the top view of

this diagonal is perpendicular to the VP and the surface is still

inclined at 450

to the HP.

5. A pentagon of side 30 mm rests on the ground on one of the corners

with sides containing the corner being equally inclined to the ground.

The side opposite to the corner on which it rests is inclined at 300

to

VP and is parallel to HP. The surface of the pentagon makes 500

with

the ground. Draw the projections of the pentagon.

6. A semicircular lamina of 60 mm diameter has its straight edge in VP

and inclined at an angle of 450

to HP. The surface of the lamina makes

an angle of 300

with VP. Draw the projections.

7. A circular lamina of 50 mm diameter rests above HP on a point P on

its circumference. If its plane is inclined at 450

to HP and the top view

of the diameter PQ makes an angle of 500

with VP, draw the

projections of the lamina.

8. A circular lamina of diameter 70 mm has the end A of the diameter AB

on HP and B on VP. Draw its projections when its surface is inclined at

500

to HP and 400

to VP.


Department of Mechanical Engineering, Sri Eshwar College of Engg 4/12

Assignment 2: Orthographic Projection of Planes

P6. A square ABCD of 40 mm side has its plane inclined at 300

to the V.P.

It’s one side is inclined at 600

to the H.P. and parallel to the V.P. Draw

its projections.

P7. A rhombus of diagonals 25mm and 15mm with longer diagonal being

parallel to XY-line represents the top view of a square of diagonal

25mm, with a corner on H.P. Draw its front view of the lamina when

the edge about which is tilted, is inclined at 450

to V.P

P8. A thin 300

– 600

set-square has its longest edge in V.P. and inclined at

300

to H.P. Its surface makes 450

with V.P. Draw its projections.

P9. A hexagonal plate of 25 mm side is resting on H.P. such that one of its

corners touches both H.P. and V.P. It makes 300

with H.P. and 600

with

V.P. Draw the projections by change of position method.

P10. A circular lamina of 60 mm diameter rests on H.P. on a point 1 on

the circumference. The lamina is inclined to H.P. such that the top

view of it is an ellipse of minor axis 35 mm. The top view of the

diameter through the point 1 makes an angle of 450

with V.P. (i) Draw

the projections. (ii) Determine the angle made by the lamina with H.P.

Orthographic Projection of Solids

1. A hexagonal prism of base side 25 mm and axis height 55 mm resting

on HP with one of its base edges, such that, the axis is inclined at 300

to HP and parallel to VP. Draw the projections of the prism.

2. A pentagonal prism of base side 25 mm and height 55 mm is resting

on HP with one of its base edges, such that the lateral surface

containing the edge is inclined at 500

to HP and perpendicular to VP.

Draw the projections.

3. A right pentagonal pyramid of side 20 mm and altitude 50 mm rests

on one of its edges of the base in the HP. The base being tilted up

such that the apex is 30 mm above HP. Draw the projection of the

pyramid when the edge on which it is resting is perpendicular to VP

4. A cylinder of diameter 35 mm and axis height 55 mm is resting on the

ground on its base. It is then tilted such that a solid diagonal is

vertical. Draw its projections.

5. A cone of diameter 35 mm and height 55 mm is lying on the ground

with a point of base on HP. The generator line passing through that

point makes an angle of 450

with HP and parallel to VP. Draw its

projections.

6. Draw the projections of a pentagonal pyramid of base side 25 mm and

axis height 60 mm with a triangular face perpendicular to HP and VP.

7. A hexagonal prism of base side 30mm and axis length 60mm rests on

the HP on one of the base corners with the base edges containing it

being equally inclined to HP. The axis is inclined at 45° to the HP and

parallel to VP. Draw the projections of the prism.

8. A cone of diameter 35mm, height 55mm is lying on the ground with

one of its generators parallel to VP and on the HP. Draw its projection.

9. A pentagonal prism of base side 25 mm and axis length 55 mm is

resting on HP on one of its rectangular faces with the axis inclined at

450

to VP. Draw its projections.

10. A cone of diameter 40mm and height 60mm is freely suspended from

one of its base points such that the axis is parallel to VP. Draw the

projection.

11. A tetrahedron of edges 35 mm rests on one of its edges on the HP.

The resting edge is perpendicular to VP and one of the triangular faces

containing the resting edge is inclined at 350

to HP. Draw the

projections of the tetrahedron.

12. A tetrahedron of side 45 mm is resting on an edge on the HP such

that the face containing that edge is seen as a triangle of base 45 mm

and altitude 25 mm in top view (TV). The axis of the tetrahedron is

parallel to the VP. Draw the projections of the tetrahedron.

UNIT III - PROJECTION OF SOLID

Projection of simple solids by rotating object method



Assignment 3: Orthographic Projection of Solids

S1. Draw the top front views of a right circular cylinder of base 45mm

diameter and 60mm long when it line on HP, such that its axis is

inclined at 30° to HP and the axis appears to parallel to the VP in the

top view

S2. Draw the projections of a pentagonal pyramid of base side 25 mm and

axis height 60 mm with a slant edge perpendicular to HP and VP.

S3. A cone of base diameter 35 mm and axis length 55 mm is resting on

HP on a point on circumference of the base. Draw the projections

when the base is perpendicular to both HP and VP.

S4. A pyramid has rectangular base of size 70 mm x 40 mm and height 85

mm. Its longer edge of base is perpendicular to HP. The axis of

pyramid is inclined at 250

to the solid assuming the apex nearer to the

observer.

S5. Draw the projections of a cube of side 30mm when it rests on one of

its corners with diagonal of the solid vertical

S6. A tetrahedron of edges 30 mm rests on one of its edges on the VP.

That edge is normal to the HP. One of the faces containing the resting

edge is inclined at 30° to the VP. Draw the projections of the

tetrahedron

S7. A Hexagonal prism, side of base 25 mm and axis 50mm long is freely

suspended from one of its base corners, such that the axis is parallel

to VP. Draw the front view and top view of the solid in the above

position.

Section of Solids

1. A cube of side 35 mm is placed on HP on a face, with two of the

vertical faces equally inclined to VP. It is cut by a plane inclined at 540

to the HP and bisecting the axis. Draw the sectional top view and find

the true shape.

2. A pentagonal pyramid of base side 25 mm and altitude 50 mm rests

on its base on HP with one of the base edges perpendicular to the VP.

It is cut by a plane inclined at 450

to the base. The cutting plane meets

the axis at 20 mm above the base. Draw the front view, sectional top

view and true shape of the section.

3. A cylinder of base diameter 35 mm and height 55 mm rests on its base

on HP. It is cut by a plane perpendicular to VP and inclined at 450

to

HP. The cutting plane meets the axis at a distance of 15 mm from the

top base. Draw the sectional plan and true shape of the section.

4. A cone of base diameter 35 mm and altitude 55 mm is resting on HP

on its base. It is cut by a plane perpendicular to VP and parallel to a

contour generator and is 10 mm away from it. Draw the front view

and sectional top view and true shape of the section.

5. A hexagonal prism of base side 25 mm and height 50 mm rests on the

HP on one of its ends with two rectangular faces parallel to the VP. It

is cut by a plane perpendicular to the HP and inclined at 500

to the VP.

It is cut by a plane perpendicular to HP and inclined at 500

to VP at a

distance of 10 mm away from the axis. Draw the top view, sectional

front view and true shape of the section.

UNIT IV - PROJECTION OF SECTIONED SOLIDS AND

DEVELOPMENT OF SURFACES

Sectioning of solids to obtain true shape of section.

Development of lateral surfaces of simple, sectioned solids and

solids with cut-outs and holes



6. A right circular cone of base diameter 40 mm and axis length 50 mm

rests on its base on HP. It is cut by a plane perpendicular to the HP

and inclined at 550

to the VP. The shortest distance between the

cutting plane and the top view of the axis is 10 mm. Draw the top

view, sectional front view and true shape of the section.

7. A pentagonal prism of base side 40 mm and axis length 80 mm is

lying on the HP on one of its rectangular faces with the axis parallel to

both HP and VP. It is cut by a plane perpendicular to HP and inclined

at 300

to VP. The section plane meets the axis at 16 mm from one of

its ends. Draw the top view, sectional front view and true shape of the

section.

8. A tetrahedron of side 60mm is resting on HP on one of its faces. It is

cut by a plane perpendicular to the VP, so that the true shape of the

cut section is a triangle of base 40mm and altitude 30mm. Locate the

plane and determine the angle of inclination of the VT with the

reference line XY. Draw the sectional top view and true shape of the

section.

Development of Surface

1. Draw the development of a cube of side 20 mm.

2. Draw the development of a pentagonal prism of side 25 mm and

height 60mm.

3. Draw the development of a cylinder of base diameter 25 mm and

height 30 mm.

4. Draw the development of a square pyramid of base side 30 mm and

height 45 mm.

5. Draw the development of a cone of base diameter 50 mm and height

60 mm.

6. Draw the development of a cube of side 40 mm resting on its face

with all the edges equally inclined to VP, which is cut by a plane

inclined at 300

to HP and perpendicular to VP and passing through the

cube at the top left corner of the cube.

7. A square pyramid of base side 30 mm and height 50 mm rests on its

base on HP, with a base edge parallel to VP. It is cut by a plane

perpendicular to VP, 500

to HP meeting the axis 30 mm above HP.

Draw the development of the lateral surfaces.

8. A lamp shade is formed by cutting a cone of base diameter 144 mm

and height 174 mm by a horizontal plane at a distance of 72 mm from

the apex and another plane inclined at 30 to HP, passing through one

of the extremities of the base. Draw the development of the shade.

Draw the development of the shade. Adopt a suitable scale.

9. A pentagonal prism of base side 30 mm and height 60 mm is cut by a

plane perpendicular to VP and 500

to HP and passing through the axis

35 mm above the base. Draw the development of the lower portion of

the solid.

10. A cylinder of diameter 40 mm, height 75 mm is cut by plane

perpendicular to VP inclined at 550

to HP meeting the axis at the top

face. Draw the lateral development of the solid.

11. A pentagonal pyramid of base side 25 mm and axis height 60 mm is

lying on the ground on its base such that one of the base edges is

parallel to and far away from VP. It is cut by cutting planes, one is

perpendicular to VP, inclined at an angle of 400

to HP and meeting the

axis at 14 mm from the base. The other plane is parallel to HP and

perpendicular to VP meeting the axis at a distance of 28 mm from the

base. Draw the lateral surface development of the cut solid.

12. A cone of 45 mm diameter and 60mm height is cut by a horizontal

plane at a distance of 15 mm from the apex and another plane

inclined at 300

to HP and meet the axis at 15 mm above the base. Draw

the development of the cone.

13. A right regular cone of 50 mm base diameter and axis 60 mm long

stands on its base on HP. A circular hole of 12 mm radius is drilled

through the axis of the cone at a height of 15 mm above the base of

the cone. The axis of the hole is perpendicular to VP. Draw the

development of the lateral surface of the cone with holes in it.



14. A hexagonal prism of side of base 35 mm and axis height 60 mm

stands on its base in HP with two of its rectangular faces parallel to

VP. A square hole of side 30 mm is drilled, such that the axis of the

hole is perpendicular to VP with all the rectangular faces of the square

hole are equally inclined to HP and bisects the axis of the prism. Draw

the development of the lateral surface of the prism showing the shape

of the hole formed in it.

Assignment 4: Sectioned Solids and Development of Surfaces

SD1. A pentagonal pyramid of base side 25 mm and altitude 60 mm

rests on the HP on one of its base with an edge parallel to the VP at a

distance of 8 mm form the axis. Draw the top view, sectional front

view and true shape of the section.

SD2. A hexagonal prism of base side 25 mm and altitude 55 mm rests

on its base on HP with two edges of the base parallel to VP. A cutting

plane parallel to the HP cuts the prism at a height of 25 mm above the

base. Draw the front view and the sectional top view.

SD3. A cone of base diameter 40 mm and altitude 50 mm rests on its

base on HP. It is cut by a section plane perpendicular to both HP and

VP, 10 mm to the right of the axis. Draw the top view, front view and

sectional side view.

SD4. A cube of side 30 mm rests on its base on the HP with a vertical

face inclined to VP. It is cut by a plane perpendicular to the VP and

inclined at 500

to HP. The plane bisects the axis of the cube. Draw the

development of the surfaces of the right portion of the cut cube.

SD5. A pentagonal pyramid of base side 30 mm and height 50 mm rests

on its base on HP, with a base edge parallel to VP. It is cut by a plane

perpendicular to VP, 500

to HP meeting the axis 30 mm above HP.

Draw the development of the lateral surfaces.

SD6. A cylinder 40mm diameter and 70mm height is resting on its base

on V.P. It is cut by plane passing through a point 50mm from the base

and inclined at 40° to V.P. A through hole of 20mm diameter is drill at

30mm above the base. Develop the lateral surface of the cylinder.

Isometric Projection

1. Draw the isometric view of a frustum of a cone of base diameter

50mm, top diameter 30mm which is resting on its base on HP with its

axis perpendicular to HP.

2. A hexagonal prism of base side 20 mm and height 40 mm has a square

hole of side 16 mm at the Centre. The axes of the square and hexagon

coincide. One of the faces of the square hole is parallel to the face of

the hexagon. Draw the isometric projection of the prism with hole to

full scale.

3. A hexagonal prism of base side 25mm and axis height 50mm rests on

HP on its base with a base edge parallel to VP. It is cut by a plane

inclined at 50° to HP and perpendicular to VP and is bisecting the axis.

Draw the isometric view of truncated prism.

4. A cylinder of 50 mm diameter and 75 mm height stands with its base

on H.P. It is cut by a section plane inclined at 45° to H.P and

perpendicular to V.P, passing through a point on the axis 20 mm

below the top end. Draw the isometric projection of the truncated

cylinder.

5. A pentagonal pyramid of base side 30 mm and axis length 65 mm is

resting on HP on its base with a side of base perpendicular to VP. It is

cut by a plane inclined at 30° to HP and perpendicular to VP and

passing through a point ON the axis at a distance of 30 mm from the

apex. Draw the isometric view of the truncated cylinder.

UNIT V - ISOMETRIC AND PERSPECTIVE PROJECTIONS

Principles of isometric projection of simple solids and

truncated solids, combination of two solid objects.

Perspective projection of simple solids - Prisms, pyramids and

cylinders by visual ray method.



6. A cone of base diameter 50mm and axis height 70 mm rests on HP on

its base. It is cut by a plane inclined at 30° to HP and perpendicular to

VP and bisects the axis. Draw the isometric view of the truncated

cone.

7. A square pyramid of base of 25mm side and 50mm long axis rests

centrally over a trapezoidal block of top and bottom bases of 40mm

and 60mm sides respectively with the thickness 30mm. Draw the

isometric projection of the arrangement.

Perspective Projection

1. A cube of 30 mm edge is resting on a face on the ground such that one

of its faces is parallel to PP and the center of the solid is 50 mm behind

the PP. The station point is 40 mm in front of the picture plane, 45 mm

above the ground plane and lies in a central plane which is 30 mm to

the left of the nearest vertical face of the cube.

2. Draw the perspective projection of a cube of 25 mm edge, lying on a

face on the ground plane, with an edge touching the picture plane and

all vertical faces equally inclined to the picture plane. The station

point is 50 mm in front of the picture plane, 35 mm above the ground

plane and lies in a central plane which is 10 mm to the left of the

center of the cube.

3. A rectangular prism of base size 25x40x60 mm rests with it’s on the

ground such that the longer base edge recedes 30° to the right of PP

with one end of it behind PP. The station point is 45mm in front of PP,

35 mm above GP and lying on a central plane 35 mm from the nearest

vertical edge. Draw the perspective view.

4. Draw the perspective projection of a pentagonal prism of base side 20

mm and height 40 mm when it rests on its base on the GP with one of

its rectangular faces parallel to and 20 mm behind the PP. The SP is 45

mm in front of PP and 60mm above GP. The observer is 30 mm to the

left of the axis.

5. A regular hexagonal pyramid of base edge 20 mm and height 35 mm

rests on its base on the ground plane with one of its base edges

touching the picture plane. The station point is 30 mm above the

ground plane and 40 mm in front of the PP. The central plane is 30 mm

to the right of the axis. Draw the perspective projection of the

pyramid.

6. A cylinder of diameter 50 mm and length 60 mm lies on ground with

its axis perpendicular to the PP and one of its circular base touching

the PP. The SP is 45 mm to the right of the axis of the cylinder, 40 mm

in front of the PP and 70mm above GP. Draw the perspective projection

of the cylinder.

Assignment 5: Isometric and Perspective Projections

IP1. A cylinder of 35 mm diameter and 55 mm height stands with its base

on H.P. It is cut by a section plane inclined at 55° to H.P and meeting

the axis at 15mm from the top end. Draw the isometric projection of

the truncated cylinder.

IP2. A cone of base diameter 25mm and height 40mm rests centrally over

a frustum of a hexagonal pyramid of base side 40mm, top base 30mm

and 60mm height. Draw the isometric view of the solid

IP3. A cylinder of diameter 50 mm rests on ground vertically with its axis

5 mm behind PP. The observer point is 40mm infront of PP, 100 mm

above GP and is 10 mm to the right of the nearest base corner point. a

central plane passing through the apex. Draw the perspective

projection.

IP4. A square prism of 55 mm edge of base and 70 mm height is placed on

the ground behind the PP with its axis vertical and one of the edges of

the base receding to the left at an angle of 40° to the PP. The nearest

vertical edge of the solid is 20 mm behind PP and 25 mm to the left of

the observer who is at a distance of 120 mm in front of PP. The height

of the observer above the ground is 100 mm. Draw the perspective

view of the prism.

IP5. A pentagonal pyramid side of base 25 mm a and height 50 mm rests

with one of its corner of the base touching the e picture plane and the

base edges passing through this corner making equal inclinations with



the picture plane. The station point is on the central line, 100 mm in

front of the picture plane and 75 mm above the e ground. Draw the

perspective view of the pyramid.

Engineering Curves: Ellipse, Parabola & Hyperbola

1. Draw the locus of a point P moving so that the ratio of its distance

from a fixed point F to its distance from a fixed straight line DD’ is ¾.

Also draw tangent and normal to the curve from any point on it.

2. Construct an ellipse given the distance of the focus from the directrix

as 60 mm and eccentricity as 2/3. Also draw tangent and normal to

the curve at a point on it 20 mm above the major axis.

3. Construct a parabola given the distance of the focus from the directrix

as 50 mm. Also draw tangent and normal to the curve from any point

on it.

4. The focus of a conic is 50 mm from the directrix. Draw the locus of a

point ‘P’ moving in such a way that its distance from the directrix is

equal to its distance from the focus. Name the curve. Draw a tangent

to the curve at a point 60 mm from the directrix.

5. Draw a hyperbola when the distance between the focus and directrix

is 40 mm and the eccentricity is 4/3. Draw a tangent and normal at

any point on the hyperbola.

6. Draw a hyperbola when the distance between its focus and directrix is

50 mm and eccentricity is 3/2. Also draw the tangent and normal at a

point 25 mm from the directrix.

Construction of Cycloid

1. A circle of 50 mm diameter rolls along a straight line without slipping.

Draw the curve traced by a point P on the circumference for one

complete revolution. Draw a tangent and normal on it 40 mm from the

base line.

2. Construct a cycloid having a rolling circle diameter as 50 mm for one

revolution. Draw a normal and tangent to the curve at a point 35 mm

above the directing line.

3. Draw an epicycloids generated by a rolling circle of diameter 40 mm

and the diameter of the directing circle is 140 mm. Also draw tangent

and normal to the curve from any point on it.

4. Draw a hypocycloid generated by a rolling circle of diameter 50 mm

and the diameter of the directing circle is 240 mm. Also draw tangent

and normal to the curve from any point on it.

Construction of Involutes

1. Draw the involute of a square of side 30 mm. Also draw tangent and

normal to the curve from any point on it.

2. A coir is unwound from a drum of 30mm diameter. Draw the locus of

the free end of the coir for unwinding through an angle of 360°. Draw

also a tangent and normal at any point on the curve.

3. An inelastic string of length 100 mm is wound round a circle of 26

mm diameter. Draw the path traced by the end of the string.

UNIT I - PLANE CURVES AND FREE HAND SKETCHING

Curves used in engineering practices

Conics – Construction of ellipse, parabola and hyperbola

by eccentricity method

Construction of cycloid

Construction of involutes of square and circle

Scales: Construction of Diagonal and Vernier scales.

Free hand sketching of multiple views from pictorial views of

objects



Scales

1. Construct a diagonal scale of R.F 1:30 to read meters,

decimeters and centimeters and long enough to measure up to

3m. Also mark a length of 1.76m on the scale.

2. The distance between Chennai and Madurai is 400 km. It is

represented by a distance of 8 cm on a railway map. Find the

R.F. and construct a diagonal scale to read kilometers. Show on

it the distance of 543 km, 212 km and 408 km.

3. Construct a vernier scale to read meters, decimeters and centimeters

and long enough to measure up to 4m. R.F of the scale is 1/20. Mark

on your scale a distance of 2.28m.

4. The actual length of 300m of an auditorium is represented by a line of

10 cm on a drawing. Draw a vernier to read up to 400m. Mark it, a

length of 343m.

Free Hand Sketching

1. Make free-hand sketches of front, top and right side views of the

pictorial view shown in the figure

2. Draw the orthographic projections of the following component using

free hand.





/12



Assignment6: Plane Curves and Free Hand Sketching

CF1. Draw the locus of a point P which moves in n a plane in such a

way that the ratio of its distances from a fixed point F and a fixed

straight line AB is always 2/3. The distance between the fixed point F

and fixed straight line is 50 mm. Also draw a tangent and normal on a

point on the locus at a horizontal distance of 55 mm from the fixed

straight line.

CF2. Draw the locus of a point P moving so that the ratio of its distance

from a fixed point F to its distance from a fixed straight line DD’ is 1.

Also draw tangent and normal to the curve from any point on it.

CF3. The vertex of a hyperbola is 30 mm from its directrix and the

eccentricity is 3/2 .Draw the hyperbola and draw the tangent and

normal at any point on the curve.

CF4. Draw the involute of a circle of diameter 40 mm and draw the

tangent and the normal to the involute at a point 95 mm from the

centre of the curve.

CF5. Draw a hypocycloid of a circle of 40 mm diameter which rolls

inside another circle of 200 mm diameter for one revolution.

CF6. Draw an epicycloid if a circle of 40 mm diameter rolls outside

another circle of 120 mm diameter for one revolution.

CF7. Draw the orthographic projections of the following component

using free hand.

Table of Content

S.No. Topic Page

No.

1 Drawing Vs. Engineering Drawing……………………………… 2

Standards 2

Drawing Sheets 2

Orientation of Drawing Sheet 3

Drawing Pencils 3

Drawing Scales 3

Line Types 4

Projection Method 4

Quadrant System 5

First Angle Projection Vs Third Angle Projection 5

Lettering Technique 5

2 Conic Sections …………………………………………………………… 6

Engineering Curves 6

3 Points …………………………………………………………………………. 7

Lines 7

Planes 8

4 Solids …………………………………………………………………………. 9

5 Sectioning of Solid ……………………………………………………. 9

Development of Surfaces of Solids. 10

6 Isomeric Projection ……………………………………………………. 10

Perspective Projection 11

Multiple Choice Quiz 11


Department of Mechanical Engineering

Basic Concepts on


Mr.S.Gokul

Assistant Professor


Sri Eshwar College of Engineering Page 2 of 12

Drawing vs. Engineering Drawing

Drawing: Describing any object/ information diagrammatically

Engineering Drawing: A drawing of an object that contains all

information like actual shape, accurate size, manufacturing

methods, etc., required for its construction without the barrier

of a language.

Standards

Standardization is the process of formulating and applying rules for

an orderly approach to a specific activity for the benefit

Standard Code

BIS standards

BIS Code Topics

IS 10711:2001 Size and Layout of Drawing

sheets

IS 10714:1983 Line Types and Uses

IS 9609:2001 Lettering

IS 15021:2001 Projection Methods

IS 11669:1986 Dimensioning

Drawing Sheets


A0 841 × 1189

A1 594 × 841

A2 420 × 594

A3 297 × 420

A4 210 × 297

A5 148 × 210

A6 105 × 148

A7 74 × 105


Page 3 of 12 Sri Eshwar College of Technology

Orientation of drawing sheet

Orientation of A3 drawing sheet

Drawing Pencils

Wooden pencils – are graded and designated by numbers and

letters

“H” for hardness “ B” for blackness

7B, 6B, 5B, 4B, 3B, 2B, B - in decreasing order of softness

and blackness

HB to F – Medium grade

H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H – increasing order of

hardness.

Drawings are done using 2H pencils and finished with H and HB

pencils – to be practiced in this course.

Drawing Scales

Scale is the ratio of the linear dimension of an element of an

object shown in the drawing to the real linear dimension of the

same element of the object.

Designation of a scale consists of the word “SCALE” followed by the

indication of its ratio, as follow

SCALE 1:1 for full size

SCALE X:1 for enlargement scales (X > 1)

SCALE 1:X for reduction scales (X > 1)



Standard reducing scales are,

1:2, 1:5, 1:10, 1:20, 1:50, 1:100

Standard enlarging scales are,

2:1, 5:1, 10:1, 20:1, 50:1, 100:1

Dimension numbers shown in the drawing are correspond to “true

size” of the object and they are independent of the scale used in

creating that drawing.

Line types

PROJECTION METHOD

PROJECTION THEORY

The projection theory is used to graphically represent 3-D objects

on 2-D media (paper, computer screen).

The projection theory is based on two variables:

1) Line of sight

2) Plane of projection (image plane or picture plane)

Line of sight is an imaginary ray of light between an

observer’s eye and an object.

Plane of projection is an imaginary flat plane which the

image is created.



Quadrant system – in 3D

Quadrant system – in 2D

First angle Projection vs Third angle Projection

First angle Projection Third angle Projection

Object placed in First Quadrant

is above HP and in front of VP

Object placed in Third Quadrant

is below HP and behind of VP

Front view is draw above

reference line

Front view is draw below

reference line

Top view is arranged below FV Top view is arranged above FV

Left side view is on the right

side of FV and Right view is on

the left side of FV

Left side view is on the left side

of FV and Right view is on the

right side of FV

Symbol

Symbol



Lettering Technique

CONIC SECTIONS

Ellipse, Parabola and Hyperbola are called conic sections because

these curves appear on the surface ff a cone when it is cut by some

typical cutting planes.

These are the loci of points moving in a plane such that the ratio of

it’s distances from a fixed point And a fixed line always remains

constant.

The Ratio is called ECCENTRICITY. (E)

A) For Ellipse E<1

B) For Parabola E=1

C) For Hyperbola E>1

Engineering curves

A curve is defined as a continuous line traced out by a moving

point, moving by constantly changing its direction

A cycloid is the curve traced by a point on the rim of a circular

wheel as the wheel rolls along a straight line.

A epicycloid is the curve traced by a point on the circumference

of a circular wheel which rolls without sipping, around the

outside of a fixed circle

A hypocycloid is the curve traced by a point on the

circumference of a circular wheel which rolls without sipping,

along the inside surface of a base circle.

Involute: it is a curve traced by an end of a string or thread, when

it’s unwounded from a circle or a polygon, the thread being kept

tight.



Points in Space

A Point may lie in space, in any one of the four quadrants, formed

by the two references planes of projections, namely, H.P and V.P.

showing the four quadrants formed by H.P. and V.P.

Positions of a Point

When a point lies in the first quadrants, it will be above H.P.

and in front of V.P.

When the point lies in the second quadrant, it will be above

H.P. and behind V.P.

When the point lies in the third quadrant, it will be below H.P.

and behind V.P.

When the point lies in the fourth quadrant, it will be in front of

V.P. and Below H.P

Lines: It’s the locus of a point which moves along the shortest

path joining two given points



Planes: A plane is a two dimensional entity (surface, Area or

object) having only length and breadth.



Solids: it’s defined as an object having three dimensions

SECTIONING OF SOLID.

A solid object is cut by some imaginary cutting plane to understand

internal details of that object.

Two cutting actions means section planes are recommended.

A) Section Plane perpendicular to Vp and inclined to Hp.

Development

B) Section Plane perpendicular to Hp and inclined to Vp.



ILLUSTRATION SHOWING IMPORTANT TERMS IN SECTIONING

DEVELOPMENT OF SURFACES OF SOLIDS

Development of surface of a solid is defined as the process of

opening out all the surfaces of a three dimensional body on to a

flat plane.

Isomeric projection: it’s a pictorial projection of an object in

which the three dimensional view of the object is shown

Isomeric projection: 0.816 times of Isomeric projection scale



Perspective Projection: it’s a drawing of any object as it appears

to the human eye.

Multiple Choice Quiz

Hidden lines are drawn as

(a) dashed narrow lines

(b) dashed wide lines

(c) long-dashed dotted wide line

(d) long-dashed double dotted wide line

Ans: (a)

Line composed of closely and evenly spaced short dashes in a

drawing represents

(a) visible edges

(b) hidden edges

(c) hatching

(d) pitch circle of gears

Ans: (b)

Lettering on a drawing sheet should have

(a) all alphabets in capital letters

(b) all alphabets in small letters

(c) In a sentance only first alphabet in capital letter

(d) In a sentance only abbreviations are capital letter

Ans: (a)

The line connecting a view to note is called

(a) dimension line

(b) projection line

(c) leader

(d) arrowheads

Ans: (c)

The dimension figure for radius of a circle should be preceded

by

(a) R

(b) CR

(c) SR

(d) RAD

Ans: (b)

Methods of arrangement of dimensions includes

(a) Parallel, continuous and combined

(b) Perpendicular, parallel and combined

(c) Perpendicular, continuous and combined

(d) Perpendicular, parallel and continuous

Ans: (a)

Superimposed dimensioning is a simplified method of

(a) chain dimensioning

(b) parallel dimensioning

(c) combined dimensioning

(d) tabular dimensioning

Ans: (b)

A curve drawn for Boyle’s law (PV = constant) on a P-V chart

has a characteristic shape of

(a) ellipse

(b) parabloa

(c) oblique hyperbola

(d) rectangular hyperbola

Ans: (d)

The profile of a gear teeth is in the form of

(a) parabola

(b) involute

(c) spiral

(d) helix

Ans: (b)

When two angles together make 90º, they are called

(a) obtuse angle

(b) reflex angle

(c) complementary angles

(d) supplementary angles

Ans: (c)



The included angle of a hexagon is

(a) 30º

(b) 60º

(c) 120º

(d) 150º

Ans: (c)

The curve generated by a point on the circumference of a circle,

which rolls without slipping along outside of another circle is

known as

(a) Hypocycloid

(b) Epicycloid

(c) Cycloid

(d) Trochoid

Ans: (b)

In orthographic projections, the rays are assumed to

(a) diverge from station point

(b) converge from station point

(c) be parallel

(d) None of these

Ans: (c)

If an object lies in third quadrant, its position with respect to

reference planes will be

(a) infront of V.P, above H.P

(b) behind V.P., above H.P.

(c) behind V.P., below H.P.

(d) infront of V.P., below H.P.

Ans: (c)

If the Vertical Trace (V.T.) of a line lies 30 mm above reference

line (XY), then its position will be

(a) 30 mm infront of V.P.

(b) 30 mm behind V.P.

(c) 30 mm above H.P.

(d) 30 mm below H.P.

Ans: (c)

When an object is cut by a section plane parallel to H.P and

perpendicular to V.P, then the sectional view of the object is

obtained in

(a) top view

(b) front view

(c) left side view

(d) right side view

Ans: (a)

Which of the following object gives a circular section, when it is

cut completely by a section plane (irrespective of the angle of

the section plane)

(a) Cylinder

(b) Sphere

(c) Cone

(d) Circular lamina

Ans: (b)

Comparative scale is a pair of scale having a common

(a) units

(b) representative fraction

(c) length of scale

(d) least count

Ans: (b)

An angle can be set off and measured with the help of

(a) plane scale

(b) diagonal scale

(c) comparative scale

(d) Scale of chords

Ans: (d)

ge8152 - engineering graphics · 2018-01-30 · ge8152 - engineering graphics mr.s.gokul (asst....

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