1. 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.
3. 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
4. PLANES
1
PRINCIPAL PLANES
HP AND VP
AUXILIARY PLANES
Auxiliary Vertical Plane Auxiliary Inclined Plane Profile Plane
(A.V.P.) (A.I.P.) ( P.P.)
A.V.P.
to Hp & to Vp
5. PATTERN OF PLANES & VIEWS (First Angle Method)
2
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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VP PP
Y
FV LSV
X Y
X TV
HP
ACTUAL PATTERN OF PLANES & VIEWS
HP IS ROTATED DOWNWARD 900 PP IS ROTATED IN RIGHT SIDE 900 OF ORTHOGRAPHIC PROJECTIONS
AND AND DRAWN IN
BROUGHT IN THE PLANE OF VP. BROUGHT IN THE PLANE OF VP. FIRST ANGLE METHOD OF PROJECTIONS
6. 3 Methods of Drawing Orthographic Projections
First Angle Projections Method Third Angle Projections Method
Here views are drawn Here views are drawn
by placing object by placing object
in 1st Quadrant in 3rd Quadrant.
( Fv above X-y, Tv below X-y ) SYMBOLIC ( Tv above X-y, Fv below X-y )
PRESENTATION
OF BOTH METHODS
WITH AN OBJECT
STANDING ON HP ( GROUND) TV
FV ON IT’S BASE.
X Y NOTE:- X Y
HP term is used in1st Angle method
& FV
TV
For the same
G L
Ground term is used
in 3rd Angle method of projections
7. FIRST ANGLE
FOR T.V.
PROJECTION
IN THIS METHOD,
THE OBJECT IS ASSUMED TO BE
SITUATED IN FIRST QUADRANT
MEANS
ABOVE HP & INFRONT OF VP.
OBJECT IS INBETWEEN
OBSERVER & PLANE.
VP PP
FV LSV
X Y
TV
HP
ACTUAL PATTERN OF
PLANES & VIEWS
IN
FIRST ANGLE METHOD
OF PROJECTIONS
8. THIRD ANGLE FOR T.V.
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
9. 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
10. FIRST ANGLE
FOR T.V.
PROJECTION
IN THIS METHOD,
THE OBJECT IS ASSUMED TO BE
SITUATED IN FIRST QUADRANT
MEANS
ABOVE HP & INFRONT OF VP.
OBJECT IS INBETWEEN
OBSERVER & PLANE.
VP PP
FV LSV
X Y
TV
HP
ACTUAL PATTERN OF
PLANES & VIEWS
IN
FIRST ANGLE METHOD
OF PROJECTIONS
11. FOR T.V.
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
12. FOR T.V.
1
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
x y
PICTORIAL PRESENTATION IS GIVEN TOP VIEW
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
13. FOR T.V.
2
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
14. FOR T.V.
3
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
15. 4
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
16. FOR T.V.
5
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
PICTORIAL PRESENTATION IS GIVEN
TOP VIEW
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
17. 6
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
18. 7
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
PICTORIAL PRESENTATION IS GIVEN TOP VIEW
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
19. STUDY 8
FOR T.V.
Z
ILLUSTRATIONS 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
20. 9
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
21. 10
FOR T.V. ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
PICTORIAL PRESENTATION IS GIVEN TOP VIEW
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
22. FOR T.V. 11
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
23. 12
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
X Y
PICTORIAL PRESENTATION IS GIVEN TOP VIEW
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
24. STUDY 13
Z
ILLUSTRATIONS FOR T.V.
ORTHOGRAPHIC PROJECTIONS
35
FV
35
10
x y
10 20 30
40
70
TV
O
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
25. STUDY
Z 14
ILLUSTRATIONS
FOR T.V. ORTHOGRAPHIC PROJECTIONS
FV
30 10 30 SV
30
10
30
x y
ALL VIEWS IDENTICAL
TV
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
26. STUDY 15
Z
ILLUSTRATIONS
ORTHOGRAPHIC PROJECTIONS
FOR T.V.
ALL VIEWS IDENTICAL
FV SV
x y
10
40 60
40
TV
60
PICTORIAL PRESENTATION IS GIVEN
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
27. FOR T.V.
ORTHOGRAPHIC PROJECTIONS 16
ALL VIEWS IDENTICAL
FV SV
x y
10
40 60
PICTORIAL PRESENTATION IS GIVEN TOP VIEW
40
DRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD 60
28. 17
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW L.H.SIDE VIEW
30 SQUARE
40 20
50
20
10
X Y
30
O 60
F.V.
S.V.
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
29. FOR T.V.
ORTHOGRAPHIC PROJECTIONS 18
FV
40
X 10 Y
O
30 D 45
O
10
50
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
80
TV
30. 19
FOR T.V.
ORTHOGRAPHIC PROJECTIONS
FV 40
X O 10 Y
100
10
25
TV
10 30 10
25
30 R O
20 D
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
31. PICTORIAL PRESENTATION IS GIVEN ORTHOGRAPHIC PROJECTIONS 20
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
30
FOR T.V.
FV
RECT.
SLOT
10 50
35
10
X Y
20 D
TV
60 D
30 D
TOP VIEW
O
32. 21
ORTHOGRAPHIC PROJECTIONS
10
25 15
25
40 10
25
25
O O
80 25
F.V. S.V.
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
33. FOR T.V.
22
ORTHOGRAPHIC PROJECTIONS
450
30
FV
40
X Y
30 D
40 TV
O
PICTORIAL PRESENTATION IS GIVEN
15
DRAW FV AND TV OF THIS OBJECT 40
BY FIRST ANGLE PROJECTION METHOD
34. 23
ORTHOGRAPHIC PROJECTIONS
HEX PART
30
20
20
40
20
O 50
20
15
O 30
100 60
PICTORIAL PRESENTATION IS GIVEN FRONT VIEW L.H.SIDE VIEW
DRAW FV ABD SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
35. FOR T.V.
ORTHOGRAPHIC PROJECTIONS 24
20 40
FRONT VIEW
F.V.
30
10
X Y
O
10
30
10
30
O 80
PICTORIAL PRESENTATION IS GIVEN T.V. TOP VIEW
DRAW FV AND TV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
36. 25
ORTHOGRAPHIC PROJECTIONS
10 10 15
25
25
X Y
O 50 10
FV LSV
PICTORIAL PRESENTATION IS GIVEN
DRAW FV AND LSV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
37. PICTORIAL PRESENTATION IS GIVEN
26 DRAW FV AND SV OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
ORTHOGRAPHIC PROJECTIONS
30 20 10 20
15
10
15
O
15
30
15
X Y
50
F.V. LEFT S.V.