GE1X01 ENGINEERING GRAPHICS Dr. M. SENTHIL KUMAR Author of Best Selling Book “ENGINEERING...

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GE1X01 ENGINEERING GRAPHICS

Dr. M. SENTHIL KUMARAuthor of Best Selling Book“ENGINEERING GRAPHICS”

Published by D.D.Publications

Email: msk67@rediffmail.com

Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.PublicationsRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

ENGINEERING DRAWING IS THE

UNIVERSAL GRAPHIC LANGUAGE

OF ENGINEERS. IT IS THE

GRAPHICAL REPRESENTATION

OF A REAL THING. IT IS USED TO

DRAW, DEVELOP, RECORD AND

CONVEY THE IDEAS, FROM ONE

TO OTHER. Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.PublicationsRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

DRAWING INSTRUMENTS

METHOD OF DIMENSIONING: METHOD - 1

METHOD OF DIMENSIONING: METHOD - 2

GEOMETRICAL CONSTRUCTIONS

To draw a regular Hexagon of side edge = R.

To draw a regular pentagon - Method IV

1.618 X 30

ERatio = 1 : 1.618

1.618 X 30

ERatio = 1 : 1.618

CONICS

Draw an ellipse when the distance of focus from the directrix is equal to 35mm

and eccentricity is 3/4.

CF = 35mm

Eccentricity = 3/4 = FD/DCCF = 35mm

PLANE CURVES

CYCLOID: It is the curve obtained when a fixed point on the circumference of a circle rolls on a plane surface, without slip. This cycloidal profile is used in designing gears tooth profiles used in clocks, conveyor linkages, …

INVOLUTE: It is the curve traced by an end of a string when unwound from a circle or a regular polygon. This involute profile is used in designing gear tooth profiles, used in designing the impeller of the centrifugal pumps, …

CYCLOID

INVOLUTE

CYCLOID

Construct a cycloid given the diameter of the generating

circle radius = 30mm.

A 1 2 3 4 5 6 7 8 9 10 11 B

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5 6 7 8 9 10 11 B

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5 6 7 8 9 10 11 B

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5 6 7 8 9 10 11 B

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5 6 7 8 9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5 6 7 8 9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5

6 7 8 9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5

7 8 9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4 5

6 7R 8 9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4

6 7R 8

9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

A 1 2 3 4

6R 7 8

9 10 11 B

10 111

CO O O O O O O

1 2 3 5 7 9 10

INVOLUTE

Construct an involute of a circle of radius 30mm. Also draw a tangent to a

point on the involute

1 2 3 4 5 6 7 8 9 10 11

1 2 3 4 5 6 7 8 9 10 111

1 2 3 4 5 6 7 8 9 10 11

1 2 3 4 5 6 7 8 9 10 114

1 2 3 4 5 6 7 8 9 10 11

PROJECTIONS OF STRAIGHT LINES

VARIOUS POSITIONS OF A STRAIGHT LINE The position of a straight line in space can be described with respect to the two reference planes are as follows

Line parallel to both the HP and VP.

Line parallel to one plane and perpendicular to other.

Line parallel to HP and perpendicular to VP.Line parallel to VP and perpendicular to HP.

Line parallel to one plane and inclined to other.Line parallel HP and inclined to VP.Line parallel to VP and inclined to HP.

Line contained by one or both the planes.Line in HP.Line in VP.Line both in HP and VP.

Line inclined to both the planes. Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.PublicationsRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

A 60mm long line CD is parallel to VP and inclined at

35° to HP. One end C is 30mm above HP and 15mm

infront of VP. Draw the projections of the line.

a’ 30

A line 70mm long has one end is 10mm above HP and

20mm infront of VP.The line is inclined at 35° to the HP and 40° to the VP.Draw the

projection of the line.

a’ 10

35°a'

a’ 10

35°a'

a’ 10

35°a'

a’ 10

35°a'

a’ 10

Locus of b

35°a'

Locus of b'

a’ 10

Locus of b

35°a'

Locus of b'

a’ 10

Locus of b

35°a'

Locus of b'

a’ 10

Locus of b

35°a'

Locus of b'

a’ 10

Locus of b

35°a'

Locus of b'

a’ 10

Locus of b

35°a'

Locus of b'

a’ 10

PROJECTIONS OF SOLIDS

A pentagonal prism of base side 30mm, axis height 70mm is lying on the ground on one of its base edges such that the axis is parallel to VP and the base is inclined at 30° to HP.

Draw the projections

(5)(4)

1' 2' 3'(5')

(5)(4)

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

a' b' c'

1' 2' 3'

(e') (d')

(5')(4')

(5)(4)

(4')30°

A right pentagonal pyramid of base side 20mm and altitude

60mm rests on one of its edges of the base in HP, the base being

lifted up until the highest corner in it is 30mm above HP. Draw the elevation of the pyramid when the

edge on which it rests is made perpendicular to VP

a' c'b' (e') (d')

a' c' c'b' (e') (d')

c'b' (e') (d')

b' (e') (d')

SECTIONS OF SOLIDS

Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

TERMS USED IN THE SECTIONS OF SOLIDSSECTION PLANE: AN IMAGINARY PLANE BY WHICH THE OBJECT IS CUT IS CALLED THE SECTION PLANE. THE LINE TYPE TO REPRESENT THIS SECTION LINE IN THE VIEW IS A THIN CHAIN LINE THICK AT THE ENDS

SECTION: THE SURFACE OF THE OBJECT CUT BY THE SECTION PLANE IS CALLED SECTIONRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

TERMS USED IN THE SECTIONS OF SOLIDS

NOTECutting plane inclined to HP and perpendicular to VP will have VT in the elevation and the top view shows the apparent section.

TERMS USED IN THE SECTIONS OF SOLIDS

SECTIONAL VIEW: THE PROJECTION OF

THE SECTION ALONG WITH THE

REMAINING PORTION OF THE OBJECT IS

CALLED SECTIONAL VIEW.

TRUE SHAPE OF THE SECTION: THE

SECTIONAL VIEW OBTAINED ON A PLANE

PARALLEL TO THE SECTION PLANE IS

CALLED THE TRUE SHAPE OF THE

SECTION.Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

A pentagonal prism axis vertical and base edge 40mm is 80mm high. It is cut by a plane perpendicular to VP,

inclined at 40° to HP bisecting the axis. Draw the true shape

of the section

Portion removed

Portion remaining

Portion removed

Portion remaining

a' e' b' d' c'

Portion removed

Portion remaining

a' e' b' d' c'

Portion removed

Portion remaining

a' e' b' d' c'

Portion removed

Portion remaining

a' e' b' d' c'

Portion removed

Portion remaining

a' e' b' d' c'

Portion removed

Portion remaining

a' e' b' d' c'

DEVELOPMENT OF SURFACES

AN OBJECT CAN BE MADE OUT OF A

SHEET METAL. WHEN ALL THE

SURFACES OF A SOLID ARE OPENED

OUT ON A PLANE, THEN THE PLANAR

PROFILE OBTAINED IS CALLED

“DEVELOPMENT”. EACH AND EVERY

LINE ON THE DEVELOPMENT SHOULD

BE THE TRUE LENGTH OF THE

RESPECTIVE LINE IN THE SURFACE

When Flat After folding

THE FOLLOWING ARE THE FOUR TYPES OF DEVELOPMENT OF SOLIDS

1.PARALLEL LINE METHOD (STRETCH-OUT METHOD)

2.RADIAL METHOD

3.TRIANGULATION METHOD

4.APPROXIMATE METHOD

METHOD OF DEVELOPMENT

While developing the solids, the bases / ends of the solid are generally omitted unless they are specifically asked and only the lateral or side faces are developed.

A pentagonal prism of base side 25mm and height 45mm

is cut by a plane perpendicular to VP and 35°

to HP and passing through the axis 25mm above the base.

Draw the development of the lower portion of the solid

a' b' e' c' d'

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

a' b' e' c' d'1'

D C B A E D

A hexagonal pyramid of base side 25mm and height 55mm rests on

its base on the ground with a base edge parallel to VP. It is cut by a

plane perpendicular to VP, inclined at 65° to HP and meets the axis at 30mm from the base.

Draw the lateral surface development

a' b' c' d'

OA=o'd'

a' b' c' d'

DEVELOPMENT SURFACES OF SOLIDS WITH SQUARE CUTOUTS

A square prism of base side 40mm and axis height 60mm is resting on the

ground on its base with all bases edge equally inclined to VP. A square hole of side 30mm is drilled centrally with

the axis perpendicular to VP, bisecting and intersecting the axis of the prism at right angles with all its rectangular faces are equally inclined to HP. Draw the development of the lateral surfaces

of the prismRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

a' b' (d') c'

A B C D A

a' b' (d') c'

A B C D A

a' b' (d') c'

A B C D A

a' b' (d') c'

A B C D A1 3

a' b' (d') c'

A B C D A1 3

a' b' (d') c'

A B C D A1 3

a' b' (d') c'

A B C D A1 3

a' b' (d') c'

A B C D A1 3

DEVELOPMENT SURFACES OF SOLIDS WITH CYLINDRICAL

CUTOUTS

A hexagonal prism of base 25mm and axis height 65mm is resting on the

ground on its base with an edge parallel to VP. A circular hole of

diameter 40mm is drilled centrally with the axis perpendicular to VP,

bisecting and intersecting the axis of the prism at right angles. Draw the

development of the lateral surfaces of the prism

1' 2' 3' 4'

b'c' d'

1' 2' 3' 4'

b'c' d'

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

b'c' d'

1 2 3 4 5 6 1

1' 2' 3' 4'

1 2 3 4 5 6 1

1' 2' 3' 4'

1 2 3 4 5 6 1

ISOMETRIC PROJECTIONS

Isometric axes: The three principal axes, which are making 120° with each other are called isometric axes

Isometric lines: The lines parallel to any one of the isometric axes are called isometric lines.

Non-Isometric lines: The lines that are not parallel to any one of the isometric axes are called non-isometric lines.

TERMS USED IN ISOMETRIC PROJECTION

ISO-LEFT

ISO-TOP

ISO-RIGHT

ISO-LEFT

ISO-RIGHT

ISO-TOP

Isometric planes: the planes containing any two isometric axes or isometric lines are called isometric planes.

Non-Isometric Planes: These are the planes that are not parallel to any of the isometric planes.

Isometric View: It is the pictorial view showing all the three dimensions of the solid with no reduction in size of the edges.

NOTEWhile drawing the isometric view of an object, only the true lengths should be used.

ISOMETRIC SCALE

ISOMETRIC LENGTHSTRUE L

ENGTHS

1 2 3 4

TRUE LENGTHS

ISOMETRIC LENGTHS

90°45°

Fig (a)

Fig (b)Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

32.6616.33

30°30°30°30°Orthographic

View IsometricProjection

IsometricView

(b) (c)

DIFFERENCE BETWEEN ISOMETRIC PROJECTION AND ISOMETRIC VIEW

OrthographicView

TO DRAW A PENTAGON IN ISOMETRIC VIEW

OrthographicView

Isometric onRight Isometric

Isometric onLeft Isometric

Isometric onTop Isometric

30° 30° 30° 30°

OrthographicView

30° 30° 30° 30°

OrthographicView

A30° 30° 30° 30°

OrthographicView

A30° 30° 30° 30°

TO DRAW THE ISOMETRIC VIEW OF A CIRCLE BY FOUR CENTRE METHOD

(i) (ii)1

30° ba

(i) (ii)1

30° b

(i) (ii)

30° b

(i) (ii)

30° b

(i) (ii)

30° b

(i) (ii)

30° b

(i) (ii)

30° b

(i) (ii)

Draw the isometric view of a rectangular prism of base size 40 X 20mm and height 60mm. Also draw the isometric view of a rectangular pyramid of the same base size and axis

height

Prism Pyramid

30° 30°

30°30°

Prism Pyramid

30° 30°

30°30°

Prism Pyramid

30° 30°

30°30°

Prism Pyramid

30° 30°

30°30°

Prism Pyramid

30° 30°

30°30°

Prism Pyramid

30° 30°

30°30°

Prism Pyramid

30° 30°

30°30°

A square prism of base side 30mm, axis 50mm height rests on

its base on the ground with its vertical faces equally inclined to VP. It is cut by a cutting plane

perpendicular to VP, inclined at 30° to the HP & bisecting the axis.

Draw the isometric view of the truncated prism

g' (f') h' e'

a'(b')

g' (f') h' e'

a'(b')

4'(2')

g' (f') h' e'

a'(b')

4'(2')

g' (f') h' e'

a'(b')

4'(2')

30°30°

g' (f') h' e'

a'(b')

4'(2')

130°30°

g' (f') h' e'

a'(b')

4'(2')

30°30°

g' (f') h' e'

a'(b')

4'(2')

30°30°

g' (f') h' e'

a'(b')

4'(2')

30°30°

g' (f') h' e'

a'(b')

4'(2')

30°30°

g' (f') h' e'

a'(b')

4'(2')

30°30°

PERSPECTIVE PROJECTIONS

It is a type of pictorial projection of an

object, which is capable of giving more

realistic appearance of the object.

When an object is viewed from a fixed

definite position, the representation of

the object on a flat plane (called picture

plane) as it would appear to the eye is

called perspective projection or

drawing

PERSPECTIVE PROJECTIONS

TERMINOLOGIES USED IN PERSPECTIVE

Auxiliary Ground Plane (AGP): It is a

horizontal plane placed above the

horizon plane. As per the third angle

projection the top view of the object is

obtained on this plane.

Picture Plane (PP): It is the vertical

transparent plane perpendicular to the

ground plane in which the perspective

of the object is obtained.Read Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

Station Point: It is the location of the

eye of the observer while viewing the

object.

Central Plane (CP): It is an imaginary

vertical plane perpendicular to both PP

and GP that contains the station point.

Ground Line (GL): It is the line of

intersection of the PP with the ground

plane.

Horizon Line (HL): It is the line of

intersection of the PP with the horizon

plane.

Perpendicular Axis (PA): (line of sight

or Axis or vision) It is the line drawn

through the station point perpendicular

to PP. It is contained by the Central

Plane.

Centre of Vision (C): It is the point of

intersection of perpendicular axis with

the picture, which lies on horizon lineRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

METHODS OF DRAWING PERSPECTIVE VIEWS

The following are the two methods to obtain perspective of an object

Visual Ray Method Vanishing Point Method

NOTEThe edges or planes, which are on PP, will retain its shape and size, even in perspective.

The faces, which are parallel to PP, will have the similar shape of the face in perspective. But the size of it depends on its position with respect to PP.

PERSPECTIVE PROJECTION BY VISUAL RAY METHOD

A point A is 10mm behind PP and 15mm above GP. The

central plane is 25mm to the left of the point. The station point is 40mm infront of PP and 50mm above GP. Draw the perspective view of the

pointRead Engineering Graphics by Dr.M.S.Kumar ; Published by D.D.Publications

A cube of side 50mm is resting on the ground on one of its faces,

with a vertical face in P.P. and the rest behind it. The central plane is

located 60mm to the left of the center of the cube. The station

point is 50mm infront of PP and 70mm above GP. Draw the perspective view of the solid

a (e) b(f)

(d') b'

(g')e' (h')GP

a (e) b(f)

(d') b'

(g')e' (h')GP

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

a (e) b(f)

(d') b'

(g')e' (h')

PICTORIAL TO ORTHOGRAPHIC PROJECTION &

FREE HAND SKETCHING

Free hand sketching is one of the most

easier and effective techniques to

communicate designs and ideas. The

idea pertaining to a new design can be

expressed on a paper, without loss of

information. Later it can be updated or

modified into suitable scale for actual

work. It is generally done without the

use of any drawing instruments.

FREE HAND SKETCHING

There are two types of freehand sketches. They are

1.Orthographic sketches / projections

2. Pictorial sketches / projections

TYPES OF FREEHAND SKETCHES

Sketch the object lines and complete the details in the views and darken the lines which are visible by thick continuous line type and the hidden ones by thick dashed line type. Draw the center mark lines for all the circles using chain line type.

Mark the dimensions, notes, … in the orthographic views.

DRAWING ORTHOGRAPHIC PROJECTIONS

Draw the Front view, Top view & Side view for the component given

THANK YOU

Dr. M. SENTHIL KUMARAuthor of Best Selling Book“ENGINEERING GRAPHICS”

Published by D.D.Publications

Email: msk67@rediffmail.com

GE1X01 ENGINEERING GRAPHICS Dr. M. SENTHIL KUMAR Author of Best Selling Book “ENGINEERING...

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