Transcript TOPICS OF “ENGINEERING GRAPHICS” (Mechanical Portion) Topic no. (C) Topic Content No. of Lectures ORTHOGRAPHIC PROJECTIONS FROM GIVEN ISOMETRIC VIEW Without Sections (D) With Sections ISOMETRIC VIEW/PROJECTIONS 05 FROM GIVEN ORTHOGRPHIC VIEWS View.

TOPICS OF “ENGINEERING GRAPHICS”
(Mechanical Portion)
Topic no.
(C)
Topic Content
No. of Lectures
ORTHOGRAPHIC PROJECTIONS
07
FROM GIVEN ISOMETRIC VIEW
Without Sections
(D)
With Sections
ISOMETRIC VIEW/PROJECTIONS 05
FROM GIVEN ORTHOGRPHIC VIEWS
View i.e. drawing
Projections
TYPES OF LINES
USED IN
ENGINEERING
DRAWING
APPLICATIONS OF
LINES ON
DRAWING
D
 40
 30
A
CONTINUOUS
THICK
B
CONTINUOUS
THIN (WAVY)
C
SHORT ZIGZAG
THIN
CONTINUOUS
THIN
SHORT DASH
MEDIUM (DOTED
D
D
150
25
E
D
LINE )
F
A
B
E
G1
C
 60
F
LONG CHAIN
THIN (CENTER
LINE)
G1
G2
CUTTING PLANE
LINE (IN F.V)
CUTTING PLANE
LINE (IN T.V)
Dimensioning Techniques
Trimmed and untrimmed drawing sheet
sizes are commercially designated as A0
(Maximum size), A1, A2, A3, A4 & A5 (Least
size).
In Engineering Graphics’ term work, all
the 4 sheets will be of A2 (approximately ½
Imperial) size
The following two systems are adopted for
dimensioning purposes on orthographic
views as well as on pictorial view.
UNIDIRECTIONAL
SYSTEM
(FOR A2 TO A5
SHEET SIZE)
(FOR LARGE SIZED
SHEETS)
20
ALIGNED
SYSTEM
20
35
H
35
ARROW HEADS
(H x 3H)
3H
ORTHOGRAPHIC PREOJECTIONS
(MULTI VIEW REPRESENTATIONS i.e. F.V.,
T.V. & S.V. – L.H.S.V OR R.H.S.V) FROM
ISOMETRIC VIEW
 PLANES OF PROJECTIONS
 QUADRANTS
 VISION DIRECTIONS
 VIEWES
 METHODS OF PROJECTIONS WITH
THEIR SYMBOLS
 SCALING OF A DRAWING (Full Size 1:1,
Reduced 1:2 or Enlarged 5:1 )
SCALING OF A DRAWING
(AS PER BUREAU OF INDIAN STANDARDS
FOR ENGINEERING DRAWING.)
RECOMMENDED SCALES
1.
FULL SCALE
e.g. 1: 1
In certain cases the engineering components may
be very large or very small for drawing purposes,
hence the corresponding scale may be preferred
from the following
2. REDUCED SCALE e.g. 1:2, 1:2.5, 1:5,
1:10, 1:20,
1:15, 1:100,
1:200, 1:500,
1:1000, 1:2000,
1:5000,
1:10000
3. ENLARGED SCALE e.g. 50:1, 20:1, 10:1,
5:1, 2:1
SYMBOLS USED ON
ENGINEERING DRAWING SHEET
FIRST ANGLE METHOD THIRD ANGLE METHOD
OF
OF
ORTHOGRAPHIC
ORTHOGRAPHIC
PROJECTIONS
PROJECTIONS
M/c. PARTS ARE NEVER ASSUMED IN SECOND
OR IN FOURTH QUADRANT, AS THE VIEWS
MAY OVERLAP ON ONE ANOTHER ABOVE XY
OR BELOW XY RESPECTIVELY.
ISOMETRIC VIEW
Y
OF
OBJECT IN
FIRST
QUADRANT
(FOR L.H.S.V.)
X
Z1
VP
PP
Y
HP
X
FIRST ANGLE METHOD OF PROJECTIONS (FOR L.H.S.V.)
Fig. 2(c) shows turning of the planes H.P & P.P
with their respective hinges, considering
V.P as fixed plane.
It may be noted that :(a) F.V. (X directional view) is on V.P, T.V. (Y
directional view) is on H.P, while L.H.S.V (Z1
directional view) is on P.P
b) F.V is within L & H, T.V is within L & D,
While L.H.S.V is within H & D.
c) The symbol for Ist angle method of projections
is placed as shown on fig. 2(c)
V.P
P.P
H
F.V.
Y
D
L.H.S.V.
X
L
T.V.
H.P
Fig. 2(c)
AIM: Fig. 2(a)
shows the Pictorial
(ISOMETRIC) view of a cut
block.
Draw
its
following
orthographic views using Ist angle
method of projections.
I. Front View
II. Top View
III.R. H. S.View
Y
Y
V.P
P.P
Fig 2(a)
Y
H.P
Z2
X
Fig 2(b)
X
Z2
Note : Ist angle means, the block is assumed in
front of V.P, above H.P and inside P.P,
as in fig. 2(b) where the F.V. is
projected on V.P, seen in X direction,
T.V. is projected on H.P, seen in Y
direction & R.H.S.V. is projected on
P.P, seen in Z2 direction
Fig. 2(c) shows turning of the planes H.P & P.P with
their respective hinges, considering plane V.P as
fixed plane.
It may be noted that :a) F.V. (X directional view) is on V.P, T.V. (Y
directional view) is on H.P, while R.H.S.V (Z2
directional view) is on P.P
b) F.V is within L & H, T.V is within L & D, While
R.H.S.V is within H & D.
c) The symbol for Ist angle method of projections is
placed as shown on fig. 2(c)
P.
P
V.P
H
D
F.V.
R.H.S.V.
Y
X
L
Fig. 2(c)
T.V.
H.P
AIM:
Fig.
3(a)
shows
the
Pictorial
(ISOMETRIC) view of a cut block.
Draw its following orthographic views
using IIIrd angle method of projections.
I.
Front View
II.
Top View
III.
Left Hand Side View
Y
Y
H.P
Y
P.P
Fig 3(a)
X
Plane H.P turned
up(above V.P)
X
V.P
Z1
Z1
Fig 3(b)
Plane P.P turned side
way(towards left side of
plane V.P)
X
Note : IIIrd
angle means, the block is
assumed behind V.P, below H.P and
inside P.P, as in fig. 3(b) where the F.V.
is projected on V.P, seen in X direction,
T.V. is projected on H.P, seen in Y
direction & L.H.S.V. is projected on
P.P, seen in Z1 direction
Fig. 3(c) shows turning of the planes H.P & P.P with
their respective hinges, considering plane V.P as
fixed plane.
It may be noted that :a) F.V. (X directional view) is on V.P, T.V. (Y
directional view) is on H.P, while L.H.S.V (Z1
directional view) is on P.P
b) F.V is within L & H, T.V is within L & D, While
L.H.S.V is within H & D.
c) The symbol for IIIrd angle method of projections
is placed as shown on fig. 3(c)
4
Fig.
3(c)
T.V.
Y
X
6
D
L
L.H.S.V
F.V.
2
AIM:
Fig.
4(a)
shows
the
Pictorial
(ISOMETRIC) view of a cut block.
Draw its following orthographic
views using IIIrd angle method of
projections.
I. Front View
II. Top View
III.Right Hand Side View
Y
Y
H.
P
X
X
Z2
Fig. 4(a)
V.P
H
Y
P.P
Fig. 4(b)
X
Z2
Planes H.P, V.P & P.P are assumed as transparent
Note : IIIrd angle means, the block is assumed
behind V.P, below H.P and inside P.P, as
in fig. 4(b) where the F.V. is projected
on V.P, seen in X direction, T.V. is
projected on H.P, seen in Y direction &
R.H.S.V. is projected on P.P, seen in Z2
direction.
Fig. 4(c) shows turning of the planes H.P &P.P with
their respective hinges, considering plane
V.P as fixed plane.
It may be noted that :a) F.V. (X directional view) is on V.P, T.V. (Y
directional view) is on H.P, while R.H.S.V (Z2
directional view) is on P.P
b) F.V is within L & H, T.V is within L & D,
While R.H.S.V is within H & D.
c) The symbol for IIIrd angle method of projections
is placed as shown on fig. 4(c)
H
.
P
D
Fig. 4(c)
T.V.
Y
X
P
.
P
H
L
F.V.
V
.
P
R.H.S.V.
Step
by
step
procedure
Suggested
to
prepare
Orthographic views (First angle
method)
for
The
simple
component Shown pictorially in
figure
60
ISOMETRIC
VIEW
20
R40
X
20
20
80
20
R.H.S.V
20
FRONT VIEW
SYMBOL IS
NOT MARKED
SCALE: 1:1
80
ø40
R40
100
TOP VIEW
FIGURE SHOWS ISOMETRIC VIEW OF A
SIMPLE OBJECT(WITHOUT DIMENSIONS)
SHOW ITS THREE ORTHOGRAPHIC VIEWS
a
1. Front View
2. Top View
3. L.H.S.View
2
Use First Angle
Method
3
c
1
b
B
A
b
B
2
3
A
1
F.V
L.H.S.V.
a
b
c
3
T.V
FIGURE SHOWS ISOMETRIC VIEW OF AN
OBJECT(WITHOUT DIMENSIONS) SHOW ITS
THREE ORTHO GRAPHIC VIEWS
a
1. Front View
2. Top View
c
3
3. L.H.S.View
b
Use Third
Angle Method
2
1
A
b
a
TOP VIEW
3
2
A
1
L.H.S VIEW
FRONT VIEW
c
Aim : Figure shows isometric
view, of a simple machine
component.
Draw its following Orthographic
views, & dimension them.
1. Front View
2. Top View
3. R.H.S. View
Use First Angle Method of projection
L = 75+25=100
H = 10+30=40
D=50
Figure
X
Figure, is the isometric view
L=100
H=40
T.V L=100
D=50
D=50
S.V H=40
F.V
10
F.V.
40
ORTHOGRAPHIC
VIEWS
25
75
T.V.
10
40 SQ
Ø30,Depth 10
30
25 SQ
10
15 SQ
ISOMETRIC
ORTHO. VIEWS
30
10
F.V.
10
5
R.H.
S.V.
15
45
25 Sq
10
40 Sq
35
40
35
5
Ø30
15 Sq
T.V.
Exercise : Figure shows the isometric
view of a vertical shaft support.
 Draw its all the three views,
using first angle method of
projections.
 Give the necessary dimensions
as per aligned system.
Ø64
ISOMETRIC
VIEW
50
24
Ø40
Ø40
50
24
Ø64
10
30
140
L.H.S.V
14
48
14
FRONT VIEW
70
TOP VIEW
Exercise :Isometric view of a rod support is
given.
Draw its all the three orthographic
views, using first angle method of
projections.
Give all the dimensions.
16
20
40
R22
X
ISOMETRIC VIEW
30
30
30
10
26
66
R22
40
20
FRONT VIEW
SCALE: 1:1
20
80
RIGHT SIDE
VIEW
140
TOP VIEW
20
10
30
R20
R8
ISOMETRIC
ORTHO. VIEWS
R20
10
30
20
8
20
16
45
30
100
25
R8
SECTIONING OF A
MACHINE COMPONENT
BY ANY ONE SECTION
PLA NE ,OUT OF THREE
FOLLOWING MENTIONED
SECTION PLANES
(1)BY A VERTICAL SECTION PLANE
(PARALLEL TO PRINCIPLE V.P.)
Hence ,
(a)The real or true shape of the section is
observed in its F.V.
(b)Section plane will be seen as a cutting
plane line (similar to center line ,thick
at
ends) with corresponding horizontal vision
direction arrows at the center of thick ends in
its T.V. & S.V.
(2)BY A HORIZONTAL SECTION PLANE
Hence,
(a)The real or true shape of the section is observed in
its T.V.
(b) The cutting or section plane will be observed as a
cutting plane line (similar to center line ,thick at
ends) with the corresponding vertically downward
vision direction arrows at the center of the thick
ends in its F.V. and in S.V.
(3) BY A SECTION PLANE , NORMAL TO
BOTH H.P. AND V.P.(i.e. parallel to
profile plane or side view plane)
Hence,
(a)The real or true shape of the section is observed in
its S.V.
(b) The cutting or section plane will be observed as a
cutting plane line (similar to center line ,thick at
ends) with the corresponding vertically downward
vision direction arrows at the center of the thick
ends in its F.V. and in T.V.
15
(2)Sectional Front view, Top
view & L.H.S.V., using 3rd
angle method of projections.
50
(1)Front view, Top view & L.H.S
View, using 3rd angle method
of projections.
15
Figure shows isometric view of a
machine component. Draw its
Ortho. Views (No sectioning)
10
1.
40
60
25
15
30
30
5
50
50
15
50
Top View
L.H.S.View
Front View
B
It will be nearer to V.P.
in 1st angle method &
against the vertical
plane in 3rd angle
method.
A
Retained split of the
machine parts
10
(With sectioning)
2.
40
60
15
25
5
A
50
A
30
30
B
50
Top View
B
L.H.S. View
Sectional Front View -AB
Figure shows the pictorial
view of a machine component.
Draw its following views as
per First angle method of
projections
(1) Front view from X direction.
(2) Sectional top view-AA
(3) L.H.S. View
20
20
60
A
A
X
20
Sketch shows the assumed cut model (retained part of
the machine component / split against the observer) due
to horizontal section plane passing through AB.
X
A
A
A
20
60
A
20
Ø20
Ø30, 7deep
14
28
120
F.V.
Sectional T.V.
L.H.S.V.
Figure shows the pictorial view
of a machine components.
Draw its following views,
using 3rd angle method of
projections.
30
B
(1) Front view from arrow X
60
(2) Top View
20
(3) Sectional R.H.S.V - AB
A
X
Retained split, will be
nearer to V.P. in 1st
angle
method
&
against the vertical
plane in 3rd angle
method.
A
B
No hatching in
this area as not
contained in the
section plane
Retained split of the
machine parts
A
40
T.V.
20 20
90
60
F.V.
20
80
A
A
SEC.
R.H.S.V
SPECIAL
SECIONS
HALF SECTION
HALF SECTIONAL F.V.-AB
B
A
C
TOP VIEW
HALF SECTIONAL
LEFT S.V.-BC
SPECIAL SECTIONS
REMOVED & REVOLVED
SECTIONS
REVOLVED
SECTION
REMOVEDSECTION
REMOVED
SECTION
REVOLVED SECTION
REMOVED SECTION
REMOVED SECTIONS