1.
Isometric Projections
Hareesha N G
Dept of Aeronautical Engg
Dayananda Sagar College of Engg
Bangalore-78
01/28/14
Hareesha N G, DSCE, Bengaluru
1

2.
ISOMETRIC DRAWING
IT IS A TYPE OF PICTORIAL PROJECTION
IN WHICH ALL THREE DIMENSIONS OF
AN OBJECT ARE SHOWN IN ONE VIEW AND
IF REQUIRED, THEIR ACTUAL SIZES CAN BE
MEASURED DIRECTLY FROM IT.
3-D DRAWINGS CAN BE DRAWN
IN NUMEROUS WAYS AS SHOWN BELOW.
ALL THESE DRAWINGS MAY BE CALLED
3-DIMENSIONAL DRAWINGS,
OR PHOTOGRAPHIC
OR PICTORIAL DRAWINGS.
HERE NO SPECIFIC RELATION
AMONG H, L & D AXES IS MENTAINED.
TYPICAL CONDITION.
IN THIS 3-D DRAWING OF AN OBJECT,
ALL THREE DIMENSIONAL AXES ARE
MENTAINED AT EQUAL INCLINATIONS
WITH EACH OTHER.( 1200)
NOW OBSERVE BELOW GIVEN DRAWINGS.
ONE CAN NOTE SPECIFIC INCLINATION
AMONG H, L & D AXES.
ISO MEANS SAME, SIMILAR OR EQUAL.
HERE ONE CAN FIND
EDUAL INCLINATION AMONG H, L & D AXES.
EACH IS 1200 INCLINED WITH OTHER TWO.
HENCE IT IS CALLED ISOMETRIC DRAWING
L
H
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H
H
Hareesha N G, DSCE, Bengaluru
2
PURPOSE OF ISOMETRIC DRAWING IS TO UNDERSTAND
OVERALL SHAPE, SIZE & APPEARANCE OF AN OBJECT PRIOR TO IT’S PRODUCTION.

3.
SOME IMPORTANT TERMS:
ISOMETRIC AXES, LINES AND PLANES:
The three lines AL, AD and AH, meeting at point A and making
1200 angles with each other are termed Isometric Axes.
The lines parallel to these axes are called Isometric Lines.
A
The planes representing the faces of of the cube as well as
other planes parallel to these planes are called Isometric Planes.
ISOMETRIC SCALE:
When one holds the object in such a way that all three dimensions
are visible then in the process all dimensions become proportionally
inclined to observer’s eye sight and hence appear apparent in lengths.
H
This reduction is 0.815 or 9 / 11 ( approx.) It forms a reducing scale which
Is used to draw isometric drawings and is called Isometric scale.
In practice, while drawing isometric projection, it is necessary to convert
true lengths into isometric lengths for measuring and marking the sizes.
This is conveniently done by constructing an isometric scale as described
on next page.
01/28/14
Hareesha N G, DSCE, Bengaluru
3

4.
TYPES OF ISOMETRIC DRAWINGS
ISOMETRIC VIEW
ISOMETRIC PROJECTION
Drawn by using True scale
( True dimensions )
Drawn by using Isometric scale
( Reduced dimensions )
D
4
3
H
E
RU
T 1
.
1 ISOM
0
0
G
EN
L
S
TH 2
300
C
4
3
2 TH S
NG
LE
450
A
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H
B
Isometric scale [ Line AC ]
requiredHareesha N G, Projection
for Isometric DSCE, Bengaluru
CONSTRUCTION OF ISOM.SCALE.
From point A, with line AB draw 30 0 and
450 inclined lines AC & AD resp on AD.
Mark divisions of true length and from
each division-point draw vertical lines
upto AC line.
The divisions thus obtained on AC
4
give lengths on isometric scale.

5.
1
AS THESE ALL ARE
2-D FIGURES
WE REQUIRE ONLY
TWO ISOMETRIC
AXES.
D
H
RECTANGLE
A
D
D
L
A
L
C
D
C
A
B
C
B
B
B
IF THE FIGURE IS
FRONT VIEW, H & L
1
AXES ARE REQUIRED.
H
TRIANGLE
B
IF THE FIGURE IS TOP
VIEW, D & L AXES
ARE REQUIRED.
2
Shapes containing
Inclined lines should
be enclosed in a
rectangle as shown.
Then first draw isom.
of that rectangle and
then inscribe that
01/28/14
shape as it is.
Isometric view if the Shape is
F.V.
or
T.V.
SHAPE
ISOMETRIC
OF
PLANE FIGURES
3
1
A
3
A
B
L
3
L
A
D
1
2
2
4
H
PENTAGON
E
1
4
D
A
E
1
D
B
D
E
A
D
C
2
4
B
Hareesha 3 G, DSCE, Bengaluru
N
C
2
3
L 1
C
A
2
B
5
L
3

6.
STUDY
Z
ILLUSTRATIONS
2
DRAW ISOMETRIC VIEW OF A
CIRCLE IF IT IS A TV OR FV.
B
FIRST ENCLOSE IT IN A SQUARE.
IT’S ISOMETRIC IS A RHOMBUS WITH
D & L AXES FOR TOP VIEW.
THEN USE H & L AXES FOR ISOMETRIC
WHEN IT IS FRONT VIEW.
FOR CONSTRUCTION USE RHOMBUS
METHOD SHOWN HERE. STUDY IT.
4
C
2
2
C
D
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1
Hareesha N G, DSCE, Bengaluru
D
1
A
4
3
3
B
A
6

7.
3
STUDY
Z
ILLUSTRATIONS
25 R
DRAW ISOMETRIC VIEW OF THE FIGURE
SHOWN WITH DIMENTIONS (ON RIGHT SIDE)
CONSIDERING IT FIRST AS F.V. AND THEN T.V.
50 MM
IF FRONT VIEW
100 MM
IF TOP VIEW
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Hareesha N G, DSCE, Bengaluru
7

8.
ISOMETRIC
OF
PLANE FIGURES
AS THESE ALL ARE
2-D FIGURES
WE REQUIRE ONLY
TWO ISOMETRIC
AXES.
SHAPE
IF F.V.
IF T.V.
4
HEXAGON
CIRCLE
IF THE FIGURE IS
FRONT VIEW, H & L
AXES ARE
REQUIRED.
IF THE FIGURE IS For Isometric of Circle/Semicircle use Rhombus method. Construct Rhombus
TOP VIEW, D & L
of sides equal to Diameter of circle always. ( Ref. topic ENGG. CURVES.)
AXES ARE
SEMI CIRCLE
REQUIRED.
For Isometric of
Circle/Semicircle
use Rhombus method.
Construct it of sides equal
to diameter of circle always.
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Hareesha N G, DSCE, Bengaluru
8
( Ref. Previous two pages.)

9.
5
STUDY
Z
ILLUSTRATIONS
ISOMETRIC VIEW OF
PENTAGONAL PYRAMID
STANDING ON H.P.
(Height is added from center of pentagon)
ISOMETRIC VIEW OF BASE OF
PENTAGONAL PYRAMID
STANDING ON H.P.
4
4
D
E
D
L
3
1
C
A
2
B
D
E
D
L
1
3
C
A
B
2
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Hareesha N G, DSCE, Bengaluru
9

10.
6
STUDY
Z
ILLUSTRATIONS
ISOMETRIC VIEW OF
PENTAGONALL PRISM
LYING ON H.P.
4
H
E
1
D
A
L
C
ISOMETRIC VIEW OF
HEXAGONAL PRISM
STANDING ON H.P.
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Hareesha N G, DSCE, Bengaluru
2
B
10
3

11.
7
STUDY
Z
ILLUSTRATIONS
CYLINDER STANDING ON H.P.
CYLINDER LYING ON H.P.
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Hareesha N G, DSCE, Bengaluru
11

12.
8
STUDY
Z
ILLUSTRATIONS
HALF CYLINDER
STANDING ON H.P.
( ON IT’S SEMICIRCULAR BASE)
HALF CYLINDER
LYING ON H.P.
( with flat face // to H.P.)
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Hareesha N G, DSCE, Bengaluru
12

13.
STUDY
Z
ILLUSTRATIONS
ISOMETRIC VIEW OF
A FRUSTOM OF SQUARE PYRAMID
STANDING ON H.P. ON IT’S LARGER BASE.
60
FV
X
40
Y
20
TV
01/28/14
Hareesha N G, DSCE, Bengaluru
13
9

14.
STUDY
ILLUSTRATION
10
PROJECTIONS OF FRUSTOM OF
PENTAGONAL PYRAMID ARE GIVEN.
DRAW IT’S ISOMETRIC VIEW.
SOLUTION STEPS:
FIRST DRAW ISOMETRIC
OF IT’S BASE.
y
x
1
4
THEN DRAWSAME SHAPE
AS TOP, 60 MM ABOVE THE
BASE PENTAGON CENTER.
D
E
THEN REDUCE THE TOP TO
20 MM SIDES AND JOIN WITH
THE PROPER BASE CORNERS.
A
TV 40 20
40
B
2
C
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60
20
60
FV
ISOMETRIC VIEW
OF
FRUSTOM OF PENTAGONAL PYRAMID
3
Hareesha N G, DSCE, Bengaluru
14

15.
ISOMETRIC VIEW OF
11
A FRUSTOM OF CONE
STANDING ON H.P. ON IT’S LARGER BASE.
STUDY
Z
ILLUSTRATIONS
60
FV
X
40
Y
20
TV
01/28/14
Hareesha N G, DSCE, Bengaluru
15

16.
STUDY
Z
ILLUSTRATIONS
PROBLEM: A SQUARE PYRAMID OF 30 MM BASE SIDES AND
50 MM LONG AXIS, IS CENTRALLY PLACED ON THE TOP OF A
CUBE OF 50 MM LONG EDGES.DRAW ISOMETRIC VIEW OF THE PAIR.
30
50
50
01/28/14
Hareesha N G, DSCE, Bengaluru
16
12

17.
13
STUDY
Z
ILLUSTRATIONS
PROBLEM: A TRIANGULAR PYRAMID
OF 30 MM BASE SIDES AND 50 MM
LONG AXIS, IS CENTRALLY PLACED
ON THE TOP OF A CUBE OF 50 MM
LONG EDGES.
DRAW ISOMETRIC VIEW OF THE PAIR.
c
a
p
o
b
a
p
o
c
b
SOLUTION HINTS.
TO DRAW ISOMETRIC OF A CUBE IS SIMPLE. DRAW IT AS USUAL.
BUT FOR PYRAMID AS IT’S BASE IS AN EQUILATERAL TRIANGLE,
IT CAN NOT BE DRAWN DIRECTLY.SUPPORT OF IT’S TV IS REQUIRED.
01/28/14
SO DRAW TRIANGLE AS A TV, SEPARATELY AND NAME VARIOUS POINTS AS SHOWN.
AFTER THIS PLACE IT ON THE TOP OF CUBE AS SHOWN.
THEN ADD HEIGHT FROM IT’S CENTER AND COMPLETE IT’S ISOMETRIC AS SHOWN.
Hareesha N G, DSCE, Bengaluru
17

18.
STUDY
Z
ILLUSTRATIONS
FV
PROBLEM:
A SQUARE PLATE IS PIERCED THROUGH CENTRALLY
BY A CYLINDER WHICH COMES OUT EQUALLY FROM BOTH FACES
OF PLATE. IT’S FV & TV ARE SHOWN. DRAW ISOMETRIC VIEW.
30
10
30
30 D
50
+
50
TV
01/28/14
Hareesha N G, DSCE, Bengaluru
18
14

19.
15
STUDY
Z
ILLUSTRATIONS
FV
PROBLEM:
A CIRCULAR PLATE IS PIERCED THROUGH CENTRALLY
BY A SQUARE PYRAMID WHICH COMES OUT EQUALLY FROM BOTH FACES
OF PLATE. IT’S FV & TV ARE SHOWN. DRAW ISOMETRIC VIEW.
30
10
30
40 SQUARE
TV
60 D
01/28/14
Hareesha N G, DSCE, Bengaluru
19

20.
16
STUDY
Z
ILLUSTRATIONS
F.V. & T.V. of an object are given. Draw it’s isometric view.
10
20
40
FV
40
X
Y
TV
50 D
30 D
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Hareesha N G, DSCE, Bengaluru
20

21.
Z
17
ISOMETRIC PROJECTIONS OF SPHERE & HEMISPHERE
r
300
Isom. Scale
r
r
r
C
R
R
r
P
TO DRAW ISOMETRIC PROJECTION
OF A HEMISPHERE
P
C = Center of Sphere.
P = Point of contact
R = True Radius of Sphere
r = Isometric Radius.
TO DRAW ISOMETRIC PROJECTION OF A SPHERE
01/28/14
r
R
P
C
R
r
Is
oDi
re
450
R
ct
io
n
STUDY
ILLUSTRATIONS
1. FIRST DRAW ISOMETRIC OF SQUARE PLATE.
2. LOCATE IT’S CENTER. NAME IT P.
3. FROM PDRAW VERTICAL LINE UPWARD, LENGTH ‘ r mm’
AND LOCATE CENTER OF SPHERE “C”
4. ‘C’ AS CENTER, WITH RADIUS ‘R’ Bengaluru
Hareesha N G, DSCE, DRAW CIRCLE.
THIS IS ISOMETRIC PROJECTION OF A SPHERE.
Adopt same procedure.
Draw lower semicircle only.
Then around ‘C’ construct
Rhombus of Sides equal to
Isometric Diameter.
For this use iso-scale.
Then construct ellipse in
this Rhombus as usual
And Complete
Isometric-Projection
of Hemi-sphere.
21

22.
18
PROBLEM:
A HEMI-SPHERE IS CENTRALLY PLACED
ON THE TOP OF A FRUSTOM OF CONE.
DRAW ISOMETRIC PROJECTIONS OF THE ASSEMBLY.
STUDY
ILLUSTRATIONS
Z
r
50 D
r
R
30 D
r
50
P
50 D
FIRST CONSTRUCT ISOMETRIC SCALE.
USE THIS SCALE FOR ALL DIMENSIONS
IN THIS PROBLEM.
450
R
r
01/28/14
300
Hareesha N G, DSCE, Bengaluru
22

23.
STUDY
Z
ILLUSTRATIONS
19
A SQUARE PYRAMID OF 40 MM BASE SIDES AND 60 MM AXIS
IS CUT BY AN INCLINED SECTION PLANE THROUGH THE MID POINT
OF AXIS AS SHOWN.DRAW ISOMETRIC VIEW OF SECTION OF PYRAMID.
3’ 4’
4
1’2’
3
X
Y
a
1
2
4
o
b
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d
1
Hareesha N G, DSCE, Bengaluru
2
3
c
23

24.
20
STUDY
Z
ILLUSTRATIONS
F.V. & T.V. of an object are given. Draw it’s isometric view.
50
X
O
Y
20
25
O
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25
Hareesha N G, DSCE, Bengaluru
20
24

25.
21
STUDY
Z
ILLUSTRATIONS
F.V. & T.V. of an object are given. Draw it’s isometric view.
35
FV
35
x
10
O
20
10
30
40
70
TV
O
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Hareesha N G, DSCE, Bengaluru
25
y

26.
STUDY
Z
ILLUSTRATIONS
24
F.V. & T.V. and S.V.of an object are given. Draw it’s isometric view.
ALL VIEWS IDENTICAL
FV
SV
y
x
10
40
40
60
TV
60
01/28/14
Hareesha N G, DSCE, Bengaluru
26

27.
STUDY
Z
ILLUSTRATIONS
F.V. & T.V. and S.V.of an object are given. Draw it’s isometric view.
ALL VIEWS IDENTICAL
FV
SV
y
x
10
40
40
60
TV
60
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25
Hareesha N G, DSCE, Bengaluru
27

28.
26
F.V. & T.V. and S.V.of an object are given. Draw it’s isometric view.
STUDY
Z
ILLUSTRATIONS
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
L.H.SIDE VIEW
20
20
x
20
O
y
50
20
30
20
20
O
20
TOP VIEW
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Hareesha N G, DSCE, Bengaluru
28

29.
27
STUDY
Z
ILLUSTRATIONS
F.V. and S.V.of an object are given.
Draw it’s isometric view.
30 SQUARE
40
20
50
20
10
O
30
F.V.
60
S.V.
O
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Hareesha N G, DSCE, Bengaluru
29

30.
28
STUDY
Z
ILLUSTRATIONS
F.V. & T.V. of an object are given. Draw it’s isometric view.
FV
40
O
10
45
30 D
10
50
O
80
TV
01/28/14
Hareesha N G, DSCE, Bengaluru
30

31.
STUDY
Z
ILLUSTRATIONS
40
FV
O
X
29
F.V. & T.V. of an object are given. Draw it’s isometric view.
10
Y
100
10
25
TV
10
30
10
25
O
30 R
20 D
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Hareesha N G, DSCE, Bengaluru
31

32.
STUDY
Z
ILLUSTRATIONS
30
F.V. & T.V. of an object are given. Draw it’s isometric view.
30
FV
RECT.
SLOT
10
50
35
10
X
O
Y
20 D
TV
60 D
30 D
01/28/14
O
Hareesha N G, DSCE, Bengaluru
32

33.
31
STUDY
Z
ILLUSTRATIONS
F.V. and S.V.of an object are given. Draw it’s isometric view.
10
25
15
25
40
10
25
25
O
O
80
F.V.
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Hareesha N G, DSCE, Bengaluru
25
S.V.
33

34.
STUDY
Z
ILLUSTRATIONS
32
F.V. & T.V. of an object are given. Draw it’s isometric view.
450
30
FV
40
X
Y
O
30 D
TV
40
01/28/14
O
40
Hareesha N G, DSCE, Bengaluru
15
34

35.
33
STUDY
Z
ILLUSTRATIONS
F.V. and S.V.of an object are given.
Draw it’s isometric view.
HEX PART
30
20
20
40
O
50
20
15
O
100
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20
Hareesha N G, DSCE, Bengaluru
30
60
35

36.
STUDY
Z
ILLUSTRATIONS
34
F.V. & T.V. of an object are given. Draw it’s isometric view.
40
20
F.V.
30
10
X
Y
O
10
30
10
30
O
80
T.V.
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Hareesha N G, DSCE, Bengaluru
36

37.
F.V. and S.V.of an object are given.
Draw it’s isometric view.
10
10
35
STUDY
Z
ILLUSTRATIONS
15
25
25
X
Y
O
50
FV
10
LSV
36
NOTE THE SMALL CHZNGE IN 2ND FV & SV.
DRAW ISOMETRIC ACCORDINGLY.
10
X
O
Y
FV
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LSV
Hareesha N G, DSCE, Bengaluru
37

38.
37
STUDY
Z
ILLUSTRATIONS
F.V. and S.V.of an object are given.
Draw it’s isometric view.
30
10
20
20
15
10
15
O
30
15
X
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O
15
Y
50
F.V.
Hareesha N G, DSCE, Bengaluru
LEFT S.V. 38

39.
38
STUDY
Z
ILLUSTRATIONS
F.V. and S.V.of an object are given.
Draw it’s isometric view.
30
10
60
O
30
O
40
F.V.
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40
S.V.
Hareesha N G, DSCE, Bengaluru
39