Contents
(ix)
Contents Preface ..............................................................................................................................(v) Acknowledgement........................................................................................................... (vii)
CHAPTER 1
Introduction 1.1
Graphics: A Tool to Communicate Ideas ....................................................... 1
1.2
Drawing Instruments and Accessories ........................................................... 2
1.3
1.2.1
Drawing Board ............................................................................. 2
1.2.2
T-Square ....................................................................................... 4
1.2.3
Set Square ..................................................................................... 4
1.2.4
Mini Drafter or Drafting Machine ................................................ 4
1.2.5
Instrument Box ............................................................................. 5
1.2.6
Drawing Pencils............................................................................ 7
1.2.7
Drawing Clips/Pins ....................................................................... 8
1.2.8
Sand Paper Block ......................................................................... 8
1.2.9
Eraser ............................................................................................ 8
1.2.10
Scale (Ruler) ................................................................................. 8
1.2.11
Engineer’s Scale .......................................................................... 9
1.2.12
French Curves ............................................................................... 9
1.2.13
Protractor ...................................................................................... 9
1.2.14
Drawing Sheet ............................................................................ 10
1.2.15
Pencil Sharpener ......................................................................... 11
1.2.16
Handkerchief or Towel Cloth ..................................................... 11
Lines ............................................................................................................. 11
Contents
(x)
1.4
Lettering ...................................................................................................... 12 1.4.1
Single Stroke Letters........................................................................ 13
1.4.2
Gothic Letters .................................................................................. 16
1.4.3
General Rules for Lettering ............................................................. 16
1.5 Dimensioning .................................................................................................. 16 1.5.1
Dimensioning Terminology ............................................................. 16
1.5.2
System of Dimensioning.................................................................. 18
1.5.3
Types of Dimensions ....................................................................... 18
1.5.4
General Rules of Dimensioning....................................................... 19
1.6 General Preparation before Commencing Engineering Drawing.................... 21 1.7 Geometrical Constructions ............................................................................. 21 1.7.1
Basic Constructions ......................................................................... 21
1.7.2
Construction of Regular Polygon .................................................... 24
1.7.3
General Methods for Regular Polygons........................................... 28
Exercises ......................................................................................................... 29
CHAPTER 2
Scales 2.1 Introduction ..................................................................................................... 31 2.2 Representative Fraction (R.F) ......................................................................... 32 2.3 Units of Measurements ................................................................................... 32 2.4 Types of Scale ................................................................................................. 33 2.5 Plain Scale ....................................................................................................... 33 2.5.1
Information Required for Construction of a Plain Scale ................. 34
2.5.2
Construction of a Plain Scale (Step-by-Step Construction)............. 34
2.6 Diagonal Scale ................................................................................................ 47 2.6.1
Principle of Diagonal Division ........................................................ 47
2.6.2
Construction of Diagonal Scale ....................................................... 48
2.7 Scale of Chords ............................................................................................... 56 Exercises ......................................................................................................... 59
Contents
(xi)
CHAPTER 3
Conic Sections 3.1 Introduction ..................................................................................................... 61 3.2 The Cone ......................................................................................................... 61 3.3 Conic Sections and their Applications ............................................................ 61 3.4 General Definition of a Conic ......................................................................... 65 3.5 Ellipse.............................................................................................................. 65 3.5.1 Construction of Ellipse .................................................................... 66 3.5.2 Construction of Ellipse by General Method (Eccentricity Method) ...................................................................... 66 3.5.3 Construction of Ellipse by Arcs of Circle Method .......................... 70 3.5.4 Construction of Ellipse by Concentric Circles Method ................... 72 3.5.5 Construction of Ellipse by Oblong (Rectangle) Method ................. 75 3.6 Parabola 3.6.1 3.6.2 3.6.3 3.6.4
......................................................................................................... 78 Construction of Parabola by General Method ................................. 79 Construction of Parabola by Offset Method .................................... 80 Construction of Parabola by Oblong Method .................................. 82 Construction of Parabola by Tangent Method ................................. 84
3.7 Hyperbola ........................................................................................................ 86 3.7.1 Construction of Hyperbola by General Method (Eccentricity Method) ........................................... 86 3.7.2 Construction of Hyperbola by Intersecting Arcs Method ................ 88 3.7.3 Rectangular Hyperbola by Asymptotes Method .............................. 91 3.8 Additional Problems on Conics ...................................................................... 93 Exercises ......................................................................................................... 99
CHAPTER 4
Engineering Curves 4.1 Introduction ................................................................................................... 101 4.2 Cycloid ......................................................................................................... 101 4.3 Epicycloid ..................................................................................................... 103
Contents
(xii)
4.4 Hypocycloid .................................................................................................. 105 4.5 Involute ......................................................................................................... 107 4.6 Spirals............................................................................................................ 111 4.6.1 Archemedian Spiral ....................................................................... 111 4.6.2 Logarithmic Spiral ......................................................................... 115 Additional Problems ................................................................................... 118 Exercises ....................................................................................................... 123
CHAPTER 5
Orthographic Projections 5.1 Projection ...................................................................................................... 125 5.2 Types of Projection ....................................................................................... 125 5.3 Orthographic Projection ................................................................................ 126 5.3.1
Important Terminology .................................................................. 126
5.3.2
Four Quadrants ............................................................................. 127
5.4 First Angle Projection Method ...................................................................... 128 5.5 Third Angle Projection.................................................................................. 128 5.6 General Procedure for Obtaining Orthographic Projections ........................ 130 5.6.1
Things to Remember...................................................................... 130
Exercises ....................................................................................................... 141
CHAPTER 6
Projections of Points 6.1 Introduction ................................................................................................... 149 6.2 Point above H.P. and in front of V.P. (i.e., in first quadrant)........................ 149 6.3 Point above H.P. and behind V.P. (i.e., in second quadrant) ........................ 150 6.4 Point below H.P. and behind V.P. (i.e., in third quadrant)............................ 151 6.5 Point below H.P. and in front of V.P. (i.e., in fourth quadrant) .................... 152 6.6 Point on the H.P. and in front of the V.P. ..................................................... 153 6.7 Point on the H.P. and behind the V.P. ......................................................... 154 6.8 Point above H.P. and in the V.P. ................................................................... 155
Contents
(xiii)
6.9 Point below H.P. and in the V.P. .................................................................. 156 6.10 Point in both H.P. and V.P. ........................................................................... 157 Exercises ....................................................................................................... 159
CHAPTER 7
Projections of Straight Lines 7.1 Introduction ................................................................................................... 161 7.2 Positions of Straight Lines ............................................................................ 161 7.3 Straight Line Parallel to both H.P. and V.P. ................................................. 162 7.4 Straight Line Parallel to V.P. and Perpendicular to H.P. .............................. 163 7.5 Straight Line Parallel to H.P. and Perpendicular to V.P. .............................. 165 7.6 Straight Line Inclined to H.P. and Parallel to V.P. ....................................... 166 7.7 Straight Line Inclined to V.P. and Parallel to H.P. ....................................... 168 7.8 Straight Line Contained by one or both the Planes ....................................... 169 7.9 Projections of Straight Lines – at a Glance ................................................... 174 7.10 Things to Remember ..................................................................................... 175 7.11 Straight Line Inclined to both H.P. and V.P.................................................. 176 7.12 Projections of Straight Line Inclined to both the Planes when True Length, True Inclinations and Positions of End Points are given and + 90o........................................................ 178 7.13 Projection of Straight Line Inclined to both the Planes when True Length, True Inclinations and Position of End Points are given and 90o ............................................................ 182 7.14 Determination of True Length and True Inclination of a Line when its Projections are given .............................................................. 185 7.15 Traces of Straight Lines ................................................................................ 188 7.16 Traces of Lines in Different Positions .......................................................... 188 7.16.1 Line Parallel to both H.P. and V.P................................................. 188 7.16.2 Line Inclined to H.P. Parallel to V.P. ............................................ 189 7.16.3 Line Inclined to V.P. and Parallel to H.P....................................... 189 7.16.4 Line Perpendicular to H.P. and parallel to V.P. ............................. 190 7.16.5 Line Perpendicular to V.P. and Parallel to H.P. ............................ 190
Contents
(xiv)
7.16.6 7.16.7 7.16.8 7.16.9
Line Contained by H.P. and Inclined to V.P. ................................ 191 Line Contained by V.P. and Inclined to H.P. ................................ 191 Line Contained by both H.P. and V.P............................................ 192 Line Inclined to both the Planes .................................................... 192
7.17 Methods of Determining Traces of a Straight Line...................................... 194 Additional Problems ................................................................................... 195 Exercises – (a) .............................................................................................. 220 Exercises - (b) .............................................................................................. 221 Exercises - (c) ............................................................................................... 222
CHAPTER 8
Projections of Planes 8.1 Introduction ................................................................................................... 227 8.2 Position of Planes .......................................................................................... 228 8.3 Traces of planes ............................................................................................ 228 8.4 Projections of Planes Perpendicular to both the Reference Planes ............... 228 8.5 Projections of Planes Parallel to one Plane and Perpendicular to other Plane ......................................................................... 230 8.6 Projections of Plane Inclined to V.P. and Perpendicular to H.P. .................. 233 8.7 Projections of Oblique Planes ....................................................................... 241 Exercises ....................................................................................................... 258
CHAPTER 9
Projections of Solids 9.1 Introduction ................................................................................................... 261 9.2 Classification of Solids ................................................................................. 261 9.2.1
Polyhedron ..................................................................................... 261
9.2.2
Solid of Revolution ........................................................................ 264
9.3 Oblique Solid ................................................................................................ 265 9.4 Truncated Solid ............................................................................................. 265
Contents
(xv)
9.5 Frustum ......................................................................................................... 266 9.6 Positions of Solid with Respect to Reference Planes (i.e., H.P and V.P) ..... 266 9.7 Axis Perpendicular to H.P ............................................................................. 266 9.8 Axis Perpendicular to V.P ............................................................................. 274 9.9 Axis Parallel to the both the H.P. and V.P. .................................................. 276 9.10 Axis Inclined to H.P. and Parallel to V.P ...................................................... 279 9.11 Axis Inclined to V.P. and Parallel to H.P ...................................................... 293 9.12 Axis Inclined to both the H.P. and the V.P ................................................... 301 9.13 Projections of Spheres ................................................................................... 321 Exercises - (a) ............................................................................................... 326 Exercises - (b) .............................................................................................. 327 Exercises - (c) ............................................................................................... 328
CHAPTER 10
Sections of Solids and Intersection of Cylinders 10.1 Introduction ................................................................................................... 331 10.2 General Terminology .................................................................................... 331 10.3 Types of Section Planes ................................................................................ 332 10.4 Sections of Prisms ......................................................................................... 335 10.4.1
Section Plane Parallel to the V.P ................................................... 335
10.4.2
Section Plane Perpendicular to the H.P. and Inclined to the V.P. (A.V.P) .................................................... 344 Section Plane Perpendicular to V.P. and Inclined to H.P.(A.I.P) ............................................................ 347
10.4.3
10.5 Sections of Pyramids ..................................................................................... 355 10.5.1 Section Plane Parallel to the H.P ................................................... 356 10.5.2 Section Plane Parallel to the V.P ................................................... 358 10.5.3 Section Plane Perpendicular to V.P. and Inclined to H.P. (A.I.P) .................................................................. 362 10.5.4 Section Plane Perpendicular to the H.P. and Inclined to V.P. (A.V.P.)......................................................... 367 10.5.5 Section Plane Perpendicular to both H.P. and V.P ........................ 372
Contents
(xvi)
10.6 Sections of Cones .......................................................................................... 373 10.6.1
Section Plane Parallel to the H.P ................................................... 373
10.6.2
Section of the Cone by a Plane Parallel to the V.P ........................ 376
10.6.3
Section Plane Perpendicular to the V.P. and Inclined to H.P. (A.I.P.) ................................................................. 378
10.6.4
Section Plane Perpendicular to H.P. and Inclined to the V.P. (A.V.P.) ................................................... 380
10.6.5
Section Plane Perpendicular to the H.P. and V.P .......................... 383
10.7 Sections of Cylinder ...................................................................................... 384 10.7.1
Section Plane Parallel to the H.P ................................................... 384
10.7.2
Section Plane Parallel to the V.P ................................................... 387
10.7.3
Section Plane Perpendicular to the V.P. and Inclined to the H.P. (A.I.P) ............................................................ 388
10.7.4
Section Plane Perpendicular to the H.P. and Inclined to the V.P. (A.V.P.) ......................................................... 392
10.8 Sections of Spheres ....................................................................................... 396 10.8.1
Section Plane Parallel to the H.P ................................................... 396
10.8.2
Section Plane Parallel to the V.P. .................................................. 397
10.8.3
Section Plane Perpendicular to the V.P. and Inclined to the H.P ......................................................................... 397
10.8.4
Section Plane Perpendicular to the H.P. and Inclined to the V.P ......................................................................... 399
10.9 Intersection of Cylinders ............................................................................... 403 10.9.1
Intersecting Cylinders have different Diameters and their Axes Intersect at Right Angle ........................................................ 404
10.9.2
Intersecting Cylinders have same Diameters and their Axes Intersect at Right Angles ...................................................... 407
10.9.3
Intersecting Cylinders have different Diameters and their Axes do not Intersect each other ............................................................. 408
Exercises - (a) ............................................................................................... 412 Exercises - (b) .............................................................................................. 416
Contents
(xvii)
CHAPTER 11
Development of Surfaces 11.1 Introduction ................................................................................................... 417 11.2 Methods of Development .............................................................................. 417 11.3 Development of Cube and Prism .................................................................. 418 11.4 Development of Cylinder .............................................................................. 432 11.5 Development of Pyramid .............................................................................. 438 11.6 Development of Cone ................................................................................... 446 11.7 Development of Sphere ................................................................................. 453 11.8 Additional Problems ..................................................................................... 456 Exercises ....................................................................................................... 464
CHAPTER 12
Isometric Projections 12.1 Introduction ................................................................................................... 469 12.2 Important Terms ............................................................................................ 471 12.3 Isometric Scale .............................................................................................. 472 12.4 Isometric Projections Vs Isometric Views .................................................... 473 12.5 Important Tips for Preparation of Isometric Drawing .................................. 474 12.6 Isometric Drawing of Plane Figures ............................................................. 474 12.7 Isometric Drawing of Solids ........................................................................ 484 12.8 Isometric Drawing of the Solid containing Non-isometric Edges ............... 485 12.9 Isometric Drawing of Solids of Revolution .................................................. 491 12.10 Isometric Drawing of Frustums .................................................................... 494 Exercises ....................................................................................................... 509
CHAPTER 13
Introduction to Computer Aided Drafting 13.1 Computer Aided Drafting (CAD) ................................................................. 517 13.2 Hardware and Software requirement of CAD System .................................. 518
Contents
(xviii)
13.3 Advantages of CAD ...................................................................................... 518 13.4 Limitations of CAD ...................................................................................... 518 13.5 Software for Creating Drawing/Design ...................................................... 518 13.6 Introduction to AutoCAD ............................................................................. 519 13.7 Beginning with AutoCAD 2009.................................................................... 519 13.8 Drawing Environment (Space) ...................................................................... 519 13.9 AutoCAD Workspace ................................................................................... 520 13.10 Setting of Drawing Space.............................................................................. 521 13.11 Sheet Layout for Printing/Plotting ................................................................ 522 13.12 Setting of Cursor Movement ........................................................................ 522 13.13 Utility Commands ......................................................................................... 522 13.14 Basic Drawing Commands............................................................................ 522 13.14.1 POINT Command ..................................................................... 523 13.14.2 LINE Command ....................................................................... 523 13.14.3 RECTANGLE or RECTANG Command................................. 526 13.14.4 CIRCLE Command ................................................................. 527 13.14.5 ARC Command ........................................................................ 530 13.14.6 ELLIPSE Command ................................................................ 534 13.14.7 POLYGON Command ............................................................ 535 13.14.8 PLINE Command ................................................................... 537 13.14.9 SPLINE Command ................................................................... 539 13.14.10 XLINE Command .................................................................... 539 13.14.11 RAY Command ........................................................................ 541 13.15 Commands for Editing and Modification ..................................................... 541 13.15.1 ERASE Command .................................................................... 541 13.15.2 UNDO Command .................................................................... 541 13.15.3 REDO Command...................................................................... 541 13.15.4 CHANGE Command .............................................................. 542 13.15.5 MIRROR Command ............................................................... 542 13.15.6 OFFSET Command ................................................................ 542 13.15.7 ARRAY Command .................................................................. 543 13.15.8 MOVE Command .................................................................... 543 13.15.9 ROTATE Command ................................................................. 543
Contents
(xix)
13.15.10 13.15.11 13.15.12 13.15.13 13.15.14 13.15.15 13.15.16 13.15.17 13.15.18 13.15.19 13.15.20 13.15.21
SCALE Command .................................................................... 544 STRETCH Command ............................................................... 544 TRIM Command ...................................................................... 544 EXTEND Command ............................................................... 545 BREAK Command .................................................................. 545 JOIN Command ....................................................................... 546 CHAMFER Command ............................................................ 546 FILLET Command ................................................................. 546 EXPLODE Command .............................................................. 547 LENGTHEN Command .......................................................... 547 EXTRUDE Command ............................................................. 547 HATCH Command ................................................................. 548
13.16 Dimensioning Commands ............................................................................. 548 13.17 Text Command .............................................................................................. 549 13.18 Projection Problems on CAD ........................................................................ 549 13.19 Typical Problems .......................................................................................... 550 Exercises ....................................................................................................... 554 Index ............................................................................................................................... 557
