FIRST YEAR ENGINEERING

ENGINEERING GRAPHICS IPresented by Prof. N. P. Jadhav Prof. S. A. LadkatDepartment of Mechanical Engineering Sinhgad Academy of Engineering, Pune

SYLLABUS Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 Curves used in Engineering Practice Orthographic Projections Auxillary Projections Isometric Projections Interpretation of Given Views/Missing Views Freehand Sketching

Weightage for each Unit SECTION I Unit 1) Unit 2) Unit 3) Engineering Curves Orthographic Projections Auxillary Projections SECTION II Unit 4) Unit 5) Unit 6) Isometric Projections Missing Views Freehand Sketching 20 20 10 15 20 15

NATURE OF QUESTION PAPER SECTION I Q 1) Q 2) Q 3) Q 4) Q 5) Q 5) Engineering Curves OR Engineering Curves Orthographic Projections OR Orthographic Projections Auxillary Projections OR Auxillary Projections 15 15 20 20 15 15

NATURE OF QUESTION PAPER SECTION II Q 7) Q 8) Q 9) Q 10) Q 11) Q 12) Isometric Projections OR Isometric Projections Missing Views OR Missing Views Freehand Sketching OR Freehand Sketching 20 20 20 20 10 10

TERM WORK Sheet No. 1 Sheet No. 2 Engineering CurvesTo draw any four curves.

Orthographic ViewsTo draw two principal views, one sectional views for two objects

Sheet No. 3

Auxillary ViewsTo draw auxillary views from the given views for any two objects.

Sheet No. 4 Sheet No. 5

Isometric ViewsTwo problems

Missing ViewsTwo problems

BOOKS

1 2 3 4

N.D. Bhatt, Elementary Engineering Drawing P.S. Gill, Engineering Graphics D. N. Johle, Engineering Drawing Engineering Graphics by M. L. Dabhade.

ORTHOGRAPHICS PROJECTIONS

Contents : * * * * * * * * * * * Types of Drawing Theory of projections Types of projections Perceptive projections Oblique projections Isometric projections Orthographic projections Quadrant systems Principal planes Glass box concept First angle projection method

Contents : * Principal projections * Conversion of pictorial view in to orthographic views * Problems

Types of DrawingsPortraits ( human faces, expressions etc.)

Nature Drawings ( landscape, Geographical scenery etc.) Drawings ( maps etc.)

Botanical Drawings ( plants, flowers etc.)

Zoological Drawings (creatures, animals etc.)

Engineering Drawings

Building Related Drawings

Machine component Drawings

Orthographic Projections(FV,TV & SV.-Mech.Engg. terms) (Plan, Elevation- Civil Engg.terms) (Working Drawings 2-D type)

Isometric ( Mech.Engg.Term.)or Perspective(Civil Engg.Term) (Actual Object Drawing 3-D)

Theory of Projection

(Plan e of

Proje

Wallct)

ction

)

(Ob

r) roje rve (P se

rs) cto

(

bje O

dow Sha(P n ectio roj )

rch To

Ball t Rays Ligh

Projection means To throw Forward. In this Object are being thrown (projected) forward in the form of Projection. Torch Torch Ball Shadow Wall Projection Ball Shadow Observer Object Projection Plane of Wall

Types of Projection Perspective Projection Oblique Projection Isometric Projection Orthographic Projection

Perspective Projection * Observer is at finite distance. * Rays or Projectors are converging at observers eye. * It does not provides exact size and shape of object.of ne la oje pr o cti n

P

ObjectStation point

oje Pr

ion ct

Orthographic ProjectionLatin Origin

* ORTHO means Perpendicular. * Assume that observer is at infinite distance and rays or Projection lines are Parallel to each other and Perpendicular to the Plane of Projection. * Since the projectors are perpendicular to the plane of projection, the view is called Orthographic View and the projection method is called Orthographic projection.

Orthographic Projection * Orthographic projection is a two dimensional projection method. * FV : Length and height of Object9090 o o

FO R

F.V .

* As projectors are Parallel to each other, the size of Orthographic View of an object is equal to the actual size of an object.

Oblique Projection * Observer is at infinite distance. * Rays or Projectors are Parallel to each other. * Rays or Projectors are not Perpendicular to the Plane of projection. (i.e. projectors are inclined to the plane of projection i.e. oblique)of e lan roj p ctio e n 90o

P

Pro jew do ha

ctor

s

s

Object

Isometric Projection * Observer is at infinite distance. * Rays or Projectors are parallel to each other & perpendicular to the plane of projection. * All faces of the object are equally inclined to the planes of projection. * All faces of the object are visible in a single view.

Quadrant system

VP 2nd Quad. Y 1ST Quad.

ObserverHP

X 3rd Quad. 4th Quad.

Quadrant system

Quadrant

Observer; Object; Plane positions

Position of object w.r.t. planes of projection

First Second Third Fourth

Observer Object Plane Observer Plane Object Observer Plane Object Observer Object Plane

Above HP, In Front of VP Above HP, Behind VP Below HP, Behind VP Below HP, In Front of VP

PRINCIPAL PLANES

TYPESHORIZONTAL PLANE VERTICAL PLANE (H P) (VP) PROFILE PLANE (PP)

Glass box concept

1st angle projection method P. P. V. P.

H. P.

1st angle projection methodNOTE

F.

V.L.H .

S.V

.

Projectors are perpendicular to respective Reference Plane and are also Parallel to each others

T.V .

NOTE

F

. .V

L.H.S.V.

Horizontal plane is rotated clockwise from the left and profile plane is rotated anticlockwise from the top so that all the three principal planes lies in a single plane .

V. T.

V .P.

P .P.

FV

LHSV

TV H

V .P.

P .P.

FV

LHSV

TV H

X1

X

FV

LHSV

Y

TV Y1

Important points for first angle projection method * Object is situated in the First Quadrant. * Object lies between the observer & Principal Planes. * Orthographic projection of an object obtained on the VP is FV & always lies above the X-Y line. * Orthographic projection of an object obtained on the HP is TV & always lies below the X-Y line. * Orthographic projection of an object obtained on the PP is SV & always lies on the side of FV & above the X-Y line. * RHSV is drawn on the left side of FV. * LHSV is drawn on the right side of FV.

PRINCIPAL PROJECTIONSDirection of Sight Plane of Projection Name of Projection

Front Top

Right Hand Left Hand Profile Plane (PP)

Vertical Plane (VP) Horizontal Plane (HP) Profile Plane (PP)

FV or Elevation TV or Plan RHSV LHSV

Conversion of Pictorial view into Orthographic Views Study of the object. Find the overall size of object i.e. Length, Width & Height. Draw blocks for F.V. (L x H), T.V. (L x W) & S.V. (W x H) in their respective position according to the method of projection. Take suitable distance of above blocks from reference lines (X-Y & X1-Y1).

Draw the view first which gives maximum visibility & which is simple to draw. In respective block, first draw the contour of the view followed by visible edges & at the end draw the hidden details. After drawing all views give all necessary dimensions (specify major dimension).

IMPORANT POINTS

CASE 1 : If line is parallel to both Vertical Plane & Horizontal Plane then Front View & Top View of the line always gives True Length on respective plane.

TL

TLTL

If line is perpendicular to one of the reference plane (say to H.P.) then the view obtained is always Point view.

IMPORANT POINTS

CASE 2 : If Plane is Parallel to V.P. then in F.V. we get True Shape of Plane while in T.V. only Line View is observed.TS

TS

If Plane is Parallel to H.P. then in T.V. we get True Shape of Plane while in F.V. only Line View is observed.

FOR T V

PROBLEM 1ORTHOGRAPHIC PROJECTIONS

X1SV

R FO

L

H

FO R

FV

FV

L.H.S.V. Y

X

TVY1

FOR T V

PROBLEM 2

ORTHOGRAPHIC PROJECTIONS

X1SV

R FO

L

H

FO R

FV

FV

L.H.S.V.

X

Y

TVY1

PROBLEM 3 Length = 63 mm Height = 37 + 10 = 47 mm Width = 40 mm F.V. = L x H = 63 x 47 T.V. = L x W = 63 x 40 S.V. = W x H = 40 x 47 X

X1

X

Y

X

Y1

PROBLEM 4 Length = 27+20+27 = 74 mm Height = 8+8+25 = 41 mm Width = 41 mm

F.V. = L x H = 74 x 41 T.V. = L x W = 74 x 41 S.V. = W x H = 41 x 41 X

X1

X

Y

X

Y1

Problem5 - Pictorial view of the object is as shown in fig. draw 1) Front View in direction of Arrow X 2) Top View 3) Right hand side view.

XX

X1

W = 44 H = 44 R.H.S.V.

L = 86 F.V H = 44 W = 44 T.V L = 86Y1

X

Y

X1

X

Y

Y1