Orthographic Projections - Basics
1.
Drawing – The fact about
2.
Drawings - Types
3.
Orthographic (Definitions and Important terms)
4.
Planes - Classifications
5.
Pattern of planes & views
6.
Methods of orthographic projections
7.
1st angle and 3rd angle method – two illustrations
Conversion of pictorial views in to orthographic views.
1.
Explanation of various terms
2.
1st angle method - illustration
3.
3rd angle method – illustration
4.
To recognize colored surfaces and to draw three Views
5.
Seven illustrations (no.1 to 7) draw different orthographic views
6.
Total nineteen illustrations ( no.8 to 26)
DRAWINGS:
( A Graphical Representation)
The Fact about:
If compared with Verbal or Written Description,
Drawings offer far better idea about the Shape, Size & Appearance of
any object or situation or location, that too in quite a less time.
Hence it has become the Best Media of Communication
not only in Engineering but in almost all Fields.
Drawings
(Some Types)
Botanical Drawings
( plants, flowers etc.)
Nature Drawings
( landscape,
Geographical
scenery etc.)
Drawings
( maps etc.)
Building Related Drawings.
Orthographic Projections
(Fv,Tv & Sv.-Mech.Engg terms)
(Plan, Elevation- Civil Engg.terms)
(Working Drawings 2-D type)
Portraits
( human faces,
expressions etc.)
Zoological Drawings
(creatures, animals etc.)
Engineering Drawings,
(projections.)
Machine component Drawings
Isometric ( Mech.Engg.Term.)
or Perspective(Civil Engg.Term)
(Actual Object Drawing 3-D)
ORTHOGRAPHIC PROJECTIONS:
IT IS A TECHNICAL DRAWING IN WHICH DIFFERENT VIEWS OF AN OBJECT
ARE PROJECTED ON DIFFERENT REFERENCE PLANES
OBSERVING PERPENDICULAR TO RESPECTIVE REFERENCE PLANE
Different Reference planes are
Horizontal Plane (HP),
Vertical Frontal Plane ( VP )
Side Or Profile Plane ( PP)
And
Different Views are Front View (FV), Top View (TV) and Side View (SV)
FV is a view projected on VP.
TV is a view projected on HP.
SV is a view projected on PP.
IMPORTANT TERMS OF ORTHOGRAPHIC PROJECTIONS:
1 Planes.
2 Pattern of planes & Pattern of views
3 Methods of drawing Orthographic Projections
PLANES
1
PRINCIPAL PLANES
HP AND VP
AUXILIARY PLANES
Auxiliary Vertical Plane
(A.V.P.)
Auxiliary Inclined Plane
(A.I.P.)

A.V.P.
 to Hp &  to Vp

Profile Plane
( P.P.)
2
PATTERN OF PLANES & VIEWS (First Angle Method)
THIS IS A PICTORIAL SET-UP OF ALL THREE PLANES.
ARROW DIRECTION IS A NORMAL WAY OF OBSERVING THE OBJECT.
BUT IN THIS DIRECTION ONLY VP AND A VIEW ON IT (FV) CAN BE SEEN.
THE OTHER PLANES AND VIEWS ON THOSE CAN NOT BE SEEN.
PROCEDURE TO SOLVE ABOVE PROBLEM:TO MAKE THOSE PLANES ALSO VISIBLE FROM THE ARROW DIRECTION,
A) HP IS ROTATED 900 DOUNWARD
B) PP, 900 IN RIGHT SIDE DIRECTION.
THIS WAY BOTH PLANES ARE BROUGHT IN THE SAME PLANE CONTAINING VP.
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PP
VP
Y
FV
LSV
Y
X
X
TV
HP
900
HP IS ROTATED DOWNWARD
AND
BROUGHT IN THE PLANE OF VP.
900
PP IS ROTATED IN RIGHT SIDE
AND
BROUGHT IN THE PLANE OF VP.
ACTUAL PATTERN OF PLANES & VIEWS
OF ORTHOGRAPHIC PROJECTIONS
DRAWN IN
FIRST ANGLE METHOD OF PROJECTIONS
3
Methods of Drawing Orthographic Projections
First Angle Projections Method
Here views are drawn
by placing object
Third Angle Projections Method
Here views are drawn
by placing object
in 1st Quadrant
in 3rd Quadrant.
( Fv above X-y, Tv below X-y )
(
SYMBOLIC
PRESENTATION
OF BOTH METHODS
WITH AN OBJECT
STANDING ON HP ( GROUND)
ON IT’S BASE.
FV
X
Y
Tv above X-y, Fv below X-y )
TV
NOTE:-
X
1st
TV
HP term is used in
Angle method
&
For the same
Ground term is used
in 3rd Angle method of projections
Y
FV
G
L
FIRST ANGLE
PROJECTION
FOR T.V.
IN THIS METHOD,
THE OBJECT IS ASSUMED TO BE
SITUATED IN FIRST QUADRANT
MEANS
ABOVE HP & INFRONT OF VP.
OBJECT IS INBETWEEN
OBSERVER & PLANE.
PP
VP
FV
LSV
Y
X
TV
HP
ACTUAL PATTERN OF
PLANES & VIEWS
IN
FIRST ANGLE METHOD
OF PROJECTIONS
THIRD ANGLE
PROJECTION
IN THIS METHOD,
THE OBJECT IS ASSUMED TO BE
SITUATED IN THIRD QUADRANT
( BELOW HP & BEHIND OF VP. )
PLANES BEING TRANSPERENT
AND INBETWEEN
OBSERVER & OBJECT.
TV
X
Y
LSV
FV
ACTUAL PATTERN OF
PLANES & VIEWS
OF
THIRD ANGLE PROJECTIONS
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
{ MACHINE ELEMENTS }
OBJECT IS OBSERVED IN THREE DIRECTIONS.
THE DIRECTIONS SHOULD BE NORMAL
TO THE RESPECTIVE PLANES.
AND NOW PROJECT THREE DIFFERENT VIEWS ON THOSE PLANES.
THESE VEWS ARE FRONT VIEW , TOP VIEW AND SIDE VIEW.
FRONT VIEW IS A VIEW PROJECTED ON VERTICAL PLANE ( VP )
TOP VIEW IS A VIEW PROJECTED ON HORIZONTAL PLANE ( HP )
SIDE VIEW IS A VIEW PROJECTED ON PROFILE PLANE ( PP )
FIRST STUDY THE CONCEPT OF 1ST AND 3RD ANGLE
PROJECTION METHODS
AND THEN STUDY NEXT 26 ILLUSTRATED CASES CAREFULLY.
TRY TO RECOGNIZE SURFACES
PERPENDICULAR TO THE ARROW DIRECTIONS
FIRST ANGLE
PROJECTION
FOR T.V.
IN THIS METHOD,
THE OBJECT IS ASSUMED TO BE
SITUATED IN FIRST QUADRANT
MEANS
ABOVE HP & INFRONT OF VP.
OBJECT IS INBETWEEN
OBSERVER & PLANE.
PP
VP
FV
LSV
Y
X
TV
HP
ACTUAL PATTERN OF
PLANES & VIEWS
IN
FIRST ANGLE METHOD
OF PROJECTIONS
THIRD ANGLE
PROJECTION
IN THIS METHOD,
THE OBJECT IS ASSUMED TO BE
SITUATED IN THIRD QUADRANT
( BELOW HP & BEHIND OF VP. )
PLANES BEING TRANSPERENT
AND INBETWEEN
OBSERVER & OBJECT.
TV
X
Y
LSV
FV
ACTUAL PATTERN OF
PLANES & VIEWS
OF
THIRD ANGLE PROJECTIONS
FOR T.V.
FOR T.V.
1
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
x
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
y
TOP VIEW
FOR T.V.
2
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
FOR T.V.
3
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
4
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
FOR T.V.
5
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
Y
TOP VIEW
6
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
7
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
Y
TOP VIEW
STUDY
Z
ILLUSTRATIONS
8
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
50
X
Y
20
25
25
20
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
9
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
Y
TOP VIEW
10
ORTHOGRAPHIC PROJECTIONS
FOR T.V.
FRONT VIEW
X
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
Y
TOP VIEW
FOR T.V.
11
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
12
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
X
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
L.H.SIDE VIEW
Y
TOP VIEW
13
STUDY
Z
ILLUSTRATIONS
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
35
FV
35
10
x
20
10
40
70
O
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
TV
30
y
STUDY
Z
ILLUSTRATIONS
14
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FV
30
10
30
SV
30
10
30
x
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
y
TV
ALL VIEWS IDENTICAL
15
STUDY
Z
ILLUSTRATIONS
ORTHOGRAPHIC PROJECTIONS
FOR T.V.
ALL VIEWS IDENTICAL
FV
SV
y
x
10
40
60
40
TV
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
60
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
16
ALL VIEWS IDENTICAL
FV
SV
y
x
10
40
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
40
60
60
TOP VIEW
17
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
40
L.H.SIDE VIEW
30 SQUARE
20
50
20
X
10
Y
30
O
F.V.
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
60
S.V.
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
18
FV
40
X
10
O
Y
45
30 D
O
10
50
80
TV
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
FOR T.V.
19
ORTHOGRAPHIC PROJECTIONS
40
FV
O
X
10
Y
100
10
25
TV
10
30 R
20 D
30
10
25
O
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
ORTHOGRAPHIC PROJECTIONS
30
FOR T.V.
FV
RECT.
SLOT
10
50
35
10
X
20 D
TV
60 D
30 D
TOP VIEW
O
Y
20
21
ORTHOGRAPHIC PROJECTIONS
10
25
15
25
40
10
25
25
O
O
80
F.V.
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
25
S.V.
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
450
30
FV
40
X
Y
30 D
TV
40
O
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
15
40
22
23
ORTHOGRAPHIC PROJECTIONS
HEX PART
30
20
20
40
O
20
50
20
15
O
PICTORIAL PRESENTATION IS GIVEN
DRAW FV ABD SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
30
60
100
FRONT VIEW
L.H.SIDE VIEW
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
24
40
20
FRONT VIEW
F.V.
30
10
X
Y
O
10
30
10
30
O
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
80
T.V.
TOP VIEW
25
ORTHOGRAPHIC PROJECTIONS
10
10
15
25
25
X
Y
O
50
FV
10
LSV
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND LSV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
26
ORTHOGRAPHIC PROJECTIONS
30
10
20
20
15
10
15
O
30
15
15
Y
X
50
F.V.
LEFT S.V.