Orthographic Projection

TOPICS OF “ENGINEERING GRAPHICS” (Mechanical Portion)Teacher : H. N. Soni

( C ) ORTHOGRAPHIC PROJECTIONS FROM GIVEN ISOMETRIC VIEW

( D ) ISOMETRIC VIEW/PROJECTIONS FROM GIVEN ORTHOGRPHIC VIEWS

Without Sections ( For First Int. Test)

With Sections ( For Second Int. Test)

View i.e. drawing Projections

For Third Internal Test

Topic no. Topic Content No. of Lectures

07

05

TYPES OF LINES USED IN

ENGINEERING DRAWING

APPLICATIONS OF LINES ON DRAWING

G2CUTTING PLANE

LINE (IN T.V)

CONTINUOUS THICK

A

A

G1CUTTING PLANE

LINE (IN F.V)G1

B CONTINUOUS THIN (WAVY)

B

C SHORT ZIGZAG THIN

C

DDD CONTINUOUS

THIN

D

ESHORT DASH

MEDIUM (DOTED LINE )

E

F LONG CHAIN THIN (CENTER

LINE)

F

40 30

2515

0

60

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.

Dimensioning Techniques

20

35

ALIGNED SYSTEM

(FOR A2 TO A5 SHEET SIZE)

UNIDIRECTIONAL SYSTEM

(FOR LARGE SIZED SHEETS)

35

20

ARROW HEADS

(H x 3H) 3H

H

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

SCALING OF A DRAWING (Full Size

1:1, Reduced 1:2 or Enlarged 5:1 )

VIEWES

METHODS OF PROJECTIONS WITH

THEIR SYMBOLS

(AS PER BUREAU OF INDIAN STANDARDS FOR ENGINEERING DRAWING.)

SCALING OF A 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

3. ENLARGED SCALE e.g. 50:1, 20:1, 10:1, 5:1, 2:1

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

PICTORIAL VIEWS OF PLANES OF ORTHO. PROJEC.

SKETCH – 1

FOR L.H.S.V. (Z1)

SKETCH – 2

FOR R.H.S.V.(Z2)

7

Y

4

82

Y

Z2

3

1

X

X

15

26

43

X

Y

Z1

Y

X

Lines, perpendicular to “Planes of projections (i.e.View planes)” called projectors

3

71

4

82

15

26

43

Y

X

X

Y

Vision directions :

XY is the line of intersection of V.P. (1 &2) and H.P. (3&4).

3

71

4

82

15

26

4 3Y

X

X

Y

Y Y

Y :- Vertically (downward) direction, for T.V. (i.e.Plan){on Pl.3 for I angle & on 4 for III angle)}

x x

X :- Horizontal direction, for F.V.(i.e.Elevation) {on Pl.1(for I angle) & on 2 (for III angle)}

Z1:- Horizontal (Perpendicular to pl.

5 & 6), for L.H.S. View, for I angle & III angle Z2:- Horizontal (Perpendicular to pl.

7 & 8), for R.H.S. View, for I angle & III angle

3

71

4

82

Z2

15

26

43

Y

X

X

Y

Z1

Y Y

x x

11

Plane Code

Plane, Called

View Projected on this

Of Proj. Method

Fixed or

Turned

1 Vertical Plane (V.P.) Above

H.P.

Front View (F.V.)

Ist AngleFixed Plane (Above XY)

XY

X Y

X X

X –FRONT VIEW DIRECTION

3D

(1,3 & 5/7)

Z2 – R.H.S.V. DIRE.X –FRONT VIEW

DIRECTION

7511

33

57

Horizontal Plane (H.P.) In front of V.P.

3 Top View (T.V.) Ist Angle

Turned Down(Below X Y)

L.H.S./R.H.S. View

Ist Angle Turned on R.H.S./L.H.S. Of 1

Profile Plane (P.P.)(On R.H.S./L.H.S of 1)

XY

X Y

Z1

Y Y

Z2X X

3D

(1,3 & 5/7)

Y – TOP VIEW DIRECTION

Z1 – L.H.S.V. DIRE.

Plane Code

Plane, Called


Of Proj. Method

Fixed or

Turned

22

44

2 Vertical Plane (V.P.)Below H.P.

Front View (F.V.)

IIIrd

AngleFixed Plane (Below XY)

Horizontal Plane (H.P.) Behind V.P.

4 Top View (T.V.)

IIIrd Angle

Turned Up(Above XY)

Plane Code

Plane, Called


Of Proj. Method

Fixed or

Turned

Y

X

X

Y

YY

XX

3D

(2, 4 & 6/8)

X –FRONT VIEW DIRECTION


86

3D

(2, 4 & 6/8)

X –FRONT VIEW DIRECTION Z2 – R.H.S.V. DIRE.


Z1 – L.H.S.V. DIRE.

Plane Code

Plane, Called


Of Proj. Method

Fixed or

Turned

Z1Z2

6/8L.H.S./R.H.S.

ViewIIIrd

Angle

Turned on L.H.S./R.H.S.

Of 2

Profile Plane (P.P.) (On

L.H.S./R.H.S of 2)

22

44Y

X

X

Y

YY

XX

1

2

3

4

X Y

V.P. above H.P.F.V. Plane

For Ist Angle

V.P. below H.P.F.V. Plane

For IIIrd Angle

H.P. In

front of V.P.

T.V.Plane for Ist Angle

H.P. Behind V.P.

T.V. Plane for IIIrd Angle

T.V. of

V.P. (1&2)

F.V. of H.P. (3&4)

F.V. of Pl. 5

F.V. Of PL.8

F.V. Of PL.6

F.V. of Pl. 7

Pl. 5 & 7 are infront of Pl. 1& Pl. 6 & 8 are behind Pl. 2

H.P. In

front of V.P.

H.P. Behind V.P.


1

2

3

4


For Ist Angle


For IIIrd Angle


IIIIII IV

5

6

L.H.S.V. Plane for IIIrd

Angle

Plane 1

Plane 2

Plane 3

Plane 4

L.H.S.V. of sketch – 1Showing Quadrants (I to IV)

Xx y

L.H.S.V. Plane for Ist Angle

5

8 6

7

Pl. 6 & 8 are behind Pl. 2Pl. 5 & 7 are infront of Pl. 1

I IIIIIIV

7

8

R.H.S.V. Plane for

IIIrd Angle

Plane 3

Plane 4

R.H.S.V. of sketchShowing Quadrants (I to IV)

X

R.H.S.V. Plane for Ist Angle

Plane 2

Plane 1

H.P. In

front of V.P.

H.P. Behind V.P.


1

2

3

4


For Ist Angle


For IIIrd Angle


x y7 5

8 6

Pl. 6 & 8 are behind Pl. 2Pl. 5 & 7 are infront of Pl. 1

SYMBOLS USED ON ENGINEERING DRAWING SHEET

FIRST ANGLE METHOD OF

ORTHOGRAPHIC PROJECTIONS

THIRD ANGLE METHOD OF

ORTHOGRAPHIC 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

OFL

F.V.T.V.

HS.V.F.V.

D S.V.T.V.

LHF.V.

LD

T.V.

HD

S.V.

FIRST ANGLE METHOD OF PROJECTIONS (FOR L.H.S.V.)

Z1

1 L.H.S.V.

T.V.

L

F.V.

L

X

F.V. Plane

T.V. Plane

L.H.S.V. Plane

Y

D

H

Y

XH

D

5

3

OBJECT IN FIRST

QUADRANT (FOR L.H.S.V.)

(i.e. within planes 1,3 &5)

Fig. 2(c) shows turning of the planes 3 & 5 with their respective hinges, considering plane 1 as fixed plane.

b) F.V is within L & H, T.V is within L & D, While L.H.S.V is within H & D.

It may be noted that :-(a) F.V. (X directional view) is on 1, T.V. (Y

directional view) is on 3, while L.H.S.V (Z1 directional view) is on 5

c) The symbol for Ist angle method of projections

is placed as shown on fig. 2(c)

Fig. 2(c)

X Y3

T.V.

L

1

F.V.

L.H.S.V.D

5

H

Note :-

XY line, boundary of planes 1,3,5 & hinges are not drawn, in actual otho. practice

Symbol here

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

X

Fig 2(b)

7

H

D

R.H.S.V.

Z2

Y

X

1

L

F.V.

3 T.V.

Z2

LD

H

Fig 2(a)

X

Y

YY

Note : Ist angle means, the block is assumed in

front of 1, above 3 and inside 7, as in

fig. 2(b) where the F.V. is projected on

1, seen in X direction, T.V. is projected

on 3, seen in Y direction & R.H.S.V. is

projected on 7, seen in Z2 direction

It may be noted that :-

a) F.V. (X directional view) is on 1, T.V. (Y directional view) is on 3, while R.H.S.V (Z2 directional view) is on 7


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)

Fig. 2(c)

3

T.V.

L

F.V.

1

X YR.H.S.V.

D

7

H

Note :-


Symbol here


(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

T.V.

4HL.H.S.V.

6

D

X

Y

Z1

X

Y

2

F.V.

L

Fig 3(b)

Y

Z1X

D

H

L

Fig 3(a)

Plane 4 turned up(above plane 2)

Plane 6 turned side way(towards left side of plane 2)

Note : IIIrd angle means, the block is

assumed behind 2, below 4 and inside

6, as in fig. 3(b) where the F.V. is

projected on 2, seen in X direction,

T.V. is projected on 4, seen in Y

direction & L.H.S.V. is projected on 6,

seen in Z1 direction

c) The symbol for IIIrd angle method of projections is placed as shown on fig. 3(c)

b) F.V is within L & H, T.V is within L & D, While L.H.S.V is within H & D.



a) F.V. (X directional view) is on 2, T.V. (Y directional view) is on 4, while L.H.S.V (Z1 directional view) is on 6

T.V.

4

D6

L.H.S.VH

2

F.V.

L

X Y

Fig. 3(c)

Note :-


Symbol here


(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

X

Y

X

Y

R.H.S.V.H

8

D

Z2

Fig. 4(b)

Planes 2, 4 & 8 are assumed as transparent

Y

Z2

Fig. 4(a)

X

4

DLT.V.

2 HL

F.V.

Note : IIIrd angle means, the block is assumed

behind 2, below 4 and inside 8, as in fig.

4(b) where the F.V. is projected on 2,

seen in X direction, T.V. is projected on

4, seen in Y direction & R.H.S.V. is

projected on 8, seen in Z2 direction.

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)



a) F.V. (X directional view) is on 2, T.V. (Y directional view) is on 4, while R.H.S.V (Z2 directional view) is on 8

XY line & boundary of planes 2,4 & 8 are not drawn, in actual otho. practice

YX

4

T.V.

D

2

F.V.

L

Fig. 4(c)Note :-

XY line, boundary of planes 2,4,8 & hinges are not drawn, in actual otho. practice.

8

R.H.S.V.

H

Symbol here

Step by step procedure

Suggested to prepare

Orthographic views (First angle

method) for The simple

component Shown pictorially in

figure

100

20

80

20

20

40

20

60

R40Ø40

ISOMETRIC ISOMETRIC VIEWVIEW XX

R40

20

100

80ø40

80

20

TOP VIEWTOP VIEW

FRONT VIEWFRONT VIEWR.H.S.VR.H.S.V

SCALE: 1:1SCALE: 1:1

SYMBOLSYMBOL IS IS NOT MARKEDNOT MARKED

20 20

R20

FIGURE SHOWS ISOMETRIC VIEW OF A SIMPLE OBJECT(WITHOUT DIMENSIONS) SHOW ITS THREE ORTHOGRAPHIC VIEWS

Use First Angle Method

1. Front View

2. Top View

3. L.H.S.ViewA

B

a

b

3

c

2

1

F.V

T.V

L.H.S.V.

B

a

bc

32

1

b

3

A

FIGURE SHOWS ISOMETRIC VIEW OF AN OBJECT(WITHOUT DIMENSIONS) SHOW ITS THREE ORTHO GRAPHIC VIEWS

Use Third Angle Method

1. Front View

2. Top View

3. L.H.S.View

1. Front View

2. Top View

3. L.H.S.ViewA

a

b

3 c

2

1

FRONT VIEWL.H.S VIEW

TOP VIEW

A

ab

3

c

2 1

Aim : Figure shows isometric view, of a simple machine component.

Draw its following Orthographic views, & dimension them.

1. Front View2. Top View3. R.H.S. View

Use First Angle Method of projection

10

10

Figure, is the isometric view

10

50

75

40

20

R25

30X

Figure

L = 75+25=100

H = 10+30=40

D=50

R2510

10

20

F.V.

5010

40

25 75

40

T.V.

R.H.S.V.

ORTHOGRAPHIC VIEWS

F.V L=100H=40

T.V L=100D=50

S.V D=50H=40

5

5

45

35

35

30

40

15

10

25 SQ

15 SQ

10

Ø30,Depth 1040 SQ

ISOMETRIC

ORTHO. VIEWS

25 Sq25 Sq

4040

1515

454535353535

15 Sq15 Sq

40 Sq40 Sq

Ø30Ø30

55

1010

3030

1010

551010

R.H.R.H.S.V.S.V.

F.V.F.V.

T.V.T.V.

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.

Exercise :-

ISOMETRIC ISOMETRIC VIEWVIEW

140

Ø40

Ø64

24

20

10

4850

25

1414

48

70

24

10

Ø40

50

Ø64

30

140

L.H.S.VL.H.S.VFRONT VIEWFRONT VIEW

TOP VIEWTOP VIEW

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.

Exercise :-Exercise :-

ISOMETRIC VIEW

16

20

4020

20

20

Ø24

R22

140

40

80 60

30

X

TOP VIEW

R22

2040

10

FRONT VIEWRIGHT SIDE

VIEW

14020

80

SCALE: 1:1

303066

26

30

108

20R20

100

45

16

20

25R8

10

30

30

ISOMETRIC

ORTHO. VIEWS

4530 8

20 25

16

R8

R2030

20

10

100

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.

50

50

50

10

3015

6040

30

15

R12.55

15

30

A

B

X

Figure shows isometric view of a machine component. Draw its

(1)Front view, Top view & L.H.S View, using 3rd angle method of projections.

(2)Sectional Front view, Top view & L.H.S.V., using 3rd angle method of projections.

10

50 50

604030

1525

5

30

50

15

Front View

Top View

L.H.S.View

1.

X

Ortho. Views (No sectioning)

A

B

A

B

X

Retained split of the machine parts

XIt will be nearer to V.P. in 1st angle method & against the vertical plane in 3rd angle method.

50 50

604030

1525

5

10

30

Top View

Sectional Front View -ABL.H.S. View

A B

A

B

B

A

2.(With sectioning)

120120

2828

2020

2020

28286060

Ø30Ø30Ø20

Ø20

1414

77AA

AA

XX

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

120120

2828

2020

Sketch shows the assumed cut model (retained part of the machine component / split against the observer) due to horizontal section plane passing through AB.

XX

120120

6060

2828

Ø30, 7deep Ø20Ø20

2020

2020

1414

F.V.F.V.

Sectional T.V.Sectional T.V.

L.H.S.V.L.H.S.V.

AA AAAA AA

6060

2020

9090

2020

4040

6060

10103030

R10R10

XXA

BFigure shows the pictorial view

of a machine components. Draw its following views, using 3rd angle method of projections.

(1) Front view from arrow X

(2) Top View

(3) Sectional R.H.S.V - AB

B

A

Retained split of the machine parts

Retained split, will be nearer to V.P. in 1st angle method & against the vertical plane in 3rd angle method.

No hatching in this area as not contained in the section plane

8080

2020

2020 2020

6060

9090

4040

3030

AA

AA

AAF.V.

T.V.

SEC.R.H.S.V

Ø30,2 HOLES

7

26

7

15

13

70

15

15

30

Ø30

R20

26

45

A

A

Ø30,2 HOLES

13

1212

2626

1515 7070

1515 15151010

2626

1313

3030

R20R20

ø30

ø30

77

6565

8181

SCECTIONAL F.V.-AASCECTIONAL F.V.-AA

TOP VIEWTOP VIEW

L.H.S.V.L.H.S.V.

7070

1010

00

A A

Aim:-Sketch-1, shows Isometric View of a Aim:-Sketch-1, shows Isometric View of a machine part. Draw its following machine part. Draw its following orthographic views using third angle orthographic views using third angle method of projections, giving dimensions.method of projections, giving dimensions.

(1) Sectional F.V.-AA(1) Sectional F.V.-AA

(2) T.V.(2) T.V.

(3) L.H.S.V(3) L.H.S.V

AA

AA

1414

88

6565

Φ20Φ20R35

R35

Φ36Φ36

7070100100

AA

AALEFT HAND SIDE VIEWLEFT HAND SIDE VIEW SECTIONAL FRONT VIEW AASECTIONAL FRONT VIEW AA

TOP VIEWTOP VIEW

XX

SCALE:- 1:1SCALE:- 1:1SYMBOL OF PROJECTION METHOD, NOT SHOWNSYMBOL OF PROJECTION METHOD, NOT SHOWN

Sketch-1Sketch-1

1414

3030

1414

7070

3434

2 HOLES,Ö 2 HOLES,Ö 1414

Ö36Ö36

Ö20Ö20

R35R3588

101000

1414

6565

1414 `̀

100

100

App

rox.

25A

ppro

x.25

AAAA

SOLUTION`SOLUTION`

1414

14141414

88

3030

7070 1414

14141414

88

100100

AA

AALEFT HAND SIDE VIEWLEFT HAND SIDE VIEW SECTIONAL FRONT VIEW AASECTIONAL FRONT VIEW AA

TOP VIEWTOP VIEWSCALE:- 1:1SCALE:- 1:1

SYMBOL OF PROJECTION METHOD, NOT SHOWNSYMBOL OF PROJECTION METHOD, NOT SHOWN

SOLUTION`SOLUTION`

App

rox.

25A

ppro

x.25

AAAA

100

100

1414

88

6565

Φ20Φ20R35

R35

Φ36Φ36

2 HOLES,Ö 2 HOLES,Ö 1414

XX

3434

Φ36Φ36

Φ20Φ20

R35R35

AA

AA

Aim:-Sketch-1, shows Isometric View of a Aim:-Sketch-1, shows Isometric View of a machine part. Draw its following machine part. Draw its following orthographic views using third angle orthographic views using third angle method of projections, giving dimensions.method of projections, giving dimensions.(1) Sectional F.V.-AA(1) Sectional F.V.-AA

(2) T.V.(2) T.V.

(3) L.H.S.V(3) L.H.S.V

1414

3030

Hatch (section) lines, to be kept at 1 to 1.5 mm apart, Hatch (section) lines, to be kept at 1 to 1.5 mm apart, at 45° normally, but depends on areas to be hatched. at 45° normally, but depends on areas to be hatched.

PROBLEM

Sketch, shows isometric view of a machine part.Draw its (1) F.V. or SEC. F.V.

(2) T.V.

(3) R.H.S.V.Use third angle method of orthographic projection. Dimension the view as per the align system.

R30

ø30

40

12

302045

20

100100

A

B

15

20

R20

Given Given Isometric Isometric viewview

L=100, D=100 & H= 100L=100, D=100 & H= 100

ø30

2045

1520

20

100

100

40

R30

100

12

60

R.H.S. VIEWR.H.S. VIEW FRONT VIEW FRONT VIEW

TOP VIEWTOP VIEW30

R20

A

B

2045

1520

20

100

100

40

ø40

R30

R20

30

100

12

BBR.H.S. VIEWR.H.S. VIEWSEC. FRONT VIEWSEC. FRONT VIEW

AATOP VIEWTOP VIEW

BBAA

60

The following figure shows the isometric view of a machine componentDraw its

1)Front view (without section &with section)2)Top view3)L.H.S view

Use First angle method of projections and dimensioning using aligned system only

PROBLEM - 1

140

25

45

12.5

12.5

35

60

55

60°

R 25

25 ,10 deep 2

5

6Web 10 th

ick

15

10

A

B

X

20

15

Z1

R 25

TOP VIEW

55

140

20

70

80

25

4525 60

451

2.5

60

10

10

6

10

10

Ø25

FRONT VIEW L.H.S. VIEW

B

55

140

20

70

80

R 25

25

45

25 60

451

2.5

60

A

B

A10

10

6

10

10

Ø25

SECTIONAL FRONT VIEW -ABL.H.S. VIEW -AB

TOP VIEW

HALF SECTION

SPECIALSECTIONS

A

C

B

HALF SECTIONAL F.V.-AB HALF SECTIONALLEFT S.V.-BC

TOP VIEW

In half section the hidden line should be used only on Un sectioned side of the view, provided that they are necessary for dimensioning or for clarity.

REMOVED & REVOLVED SECTIONS

SPECIAL SECTIONS

REMOVEDSECTION

REVOLVEDSECTION

REMOVEDSECTION

REVOLVED SECTION

REMOVED SECTION

REMOVED SECTIONS

NOTE:- (As per Previous I S 696 – 1972 Page 38)

When the cutting plane passes (contains) the center line of such elements as, Shafts, bolts, nuts, rods, rivets, keys, pins, pulley arms, spokes, webs (ribs), screws, ball or roller bearings or similar shapes - no section lining or sectioning is needed for the objects , i.e. the hatching should be eliminated.(See the next demonstrating exercises following the above rule)

Vertical Collared Shaft (supported on webbed and drilled flange) in Conventional section in F.V., along withthe T.V.

Note:- As a rule, all the hidden lines should be omitted from a sectional view. The only exemption is where the hidden lines are absolutely Indispensable for clarification or for dimensioning.

Actual or true projections are not preferred to draw

Section lines are to be staggered as

shown at R

OFFSET SECTION: The path of the cutting plane is bent to pass through features not located in a straight line, i.e. it is offset to pass through both principle features of the object. Example is shown below in Ex. 1 & Ex. 2.

B

BEx. 1.

R

AA

P Q

F.V (SECTION –AA)

Section lines are to be staggered as shown at P,Q

Ex. 2.

Off set sectioning

pulley

Tap bolt(fastener)

shaft

Shaft and pulley partly broken out to show internal fastening

This is used to show only a desired features of the object . No cutting plane lines are necessary , shown by wavy line

Partial (broken, local or Zonal)

Section.

See Ex. A,B & C

Ex. A

Partial (broken, local or Zonal)

Section.

Ex. B

SPECIAL SECTION SECTION IN TWO INTERSECTING PLANES

A

B

SEC. F.V. - ABR.H.S.V.

SPECIAL SECTION

Cross hatching of adjacent parts See at (1) & (2)

(1)

Hatching more than two adjacent components at (2)

(2)

A

B

C

(hatchedat 60 )

D45

45

hatchedat 30on D

SPECIAL SECTION

A B

F.V.

SEC.T.V.Two vertical plates ,fastened by a horizontalrivet is shown in its F.V. & T.V., cut by horizontalsection plane. Note the rivet is shown in section inT.V.

CONVENTIONAL REPRESENTATIONOF CYLINDER IN WHICH CIRCULAR OR RECTANGULAR HOLE CUT IN ITS F.V.Note:- The actual shape of hole or slot may be understood fromits side view.

For circular hole

For rectangular slot

ACTUALPROJECTIONS

AUXILARY SECTION

A

SECTION AA

A

It is the sectional view not in principal planes. it may be full, half ,broken out , removed or revolved. The section should be shown in its normal auxiliary position and clearly identified with a cutting plane with letters

AUXILIARY SECTION (as specialsection)

A

A

BC D

DCB

SECTIONAA SECTION

BBSECTION

CC

SECTIONDD

SUCCESSIVE SECTIONS (REMOVED TYPE)

A

A

BC D

DCB


SECTIONAA SECTION

BBSECTION

CCSECTION

DD


Orthographic Projection

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Transcript of Orthographic Projection