Engineering Graphics with AutoCAD

James D. Bethune

Boston University

Prentice Hall

Englewood Cliffs, New Jersey Columbus, Ohio

Chapter 1 - Creating a Drawing 1

1-1 Introduction 1 1-2 Reading This Book Notations 5 1-3 HELP 5 1-4 Starting a Drawing 5 1-5 UNITS 7 1-6 LIMITS 7 1-7 GRID 9 1-8 SNAP 9 1-9 Toggle Keys 10 1-10 Lines 10 1-11 Sample Problem SP1-1 12 1-12ERASE 14 1-13 UNDO 15 1-14 REDO 15 1-15 ZOOM 15 1-16REDRAW 17 1-17 SAVE 18 1-18 TEXT 18 1-19 Sample Drawing - SP1-2 21 1-20 Prototype Drawing 23 1-21 Drawing Formats 23 1-22 Exercise Problems 27

Contents

Chapter 2 - Draw and Edit Commands 31

2-1 Introduction 31 2-2Circles 31 2-3 Center Lines 34 2-4Trim 37 2-5 Sample Problem SP2-1 38 2-6 Sample Problem SP2-2 39 2-7 Exercise Problems 40 2-8ARCS 41 2-9 POLYGONS 43 2-10EXPLODE 44 2-11 Sample Problem SP2-3 45 2-12 Exercise Problems 47 2-13 MOVE 49 2-14 COPY 49 2-15 ROTATE 50 2-16MIRROR 51 2-17 OFFSET 52 2-18 FILLET 52 2-19 Sample Problem SP2-4 54 2-20 Exercise Problems 55 2-21 ARRAY 56 2-22 CHAMFER 57 2-23 BREAK 57

ix

X CONTENTS

2-24EXTEND 58 2-25 STRETCH 59 2-26 SCALE 59 2-27 PLDSfE and PEDIT (Irregulär Curves) 60 2-28 ELLIPSE 62 2-29 Exercise Problems 64

Chapter 3 - Construction Techniques 73

3-1 Introduction 73 3-2 OSNAP 73 3-3 CENTER (OSNAP) 74 3-4 ENDPOINT (OSNAP) 74 3-5 INSERT (OSNAP) 74 3-6INTERSECTION (OSNAP) 75 3-7 MIDPOINT (OSNAP) 75 3-8 NEAREST (OSNAP) 76 3-9 PERPENDICULAR (OSNAP) 76 3-10 QUADRANT (OSNAP) 76 3-11 TANGENT (OSNAP) 77 3-12 Sample Problem SP3-1 77 3-13 Sample Problem SP3-2 78 3-14 Exercise Problems 79 3-15 GRIPS 80 3-16 STRETCH (GRIPS) 81 3-17 MOVE (GRIPS) 81 3-18 ROTATE (GRIPS) 82 3-19 SCALE (GRIPS) 82 3-20 MIRROR (GRIPS) 82 3-21 BLOCK 83 3-22 Sample Problem SP3-3 84 3-23 WBLOCK 85 3-24LAYER 85 3-25 Constructing a Hexagon Inscribed Within

aCircle 89 3-26 Constructing the Bisect of an Angle

MethodI 89 3-27 Constructing the Bisect of an Angle

MethodH 90 3-28 Construct an Ogee Curve with Equal Ares 90 3-29 Construct a Parabola 91 3-30 Construct a Hyperbola 92 3-31 Construct a Spiral 92 3-32 Construct a Helix 93 3 33 Exercise Problems 94 3-34 Just for Fun 106

Chapter 4 - Sketching 109

4-1 Introduction 109 4-2 Establish Your Own Style 109 4-3 Graph Paper 109 4-4Pencils 110 4-5 Lines 110 4-6 Proportions 111 4-7 Exercise Problems 112 4-8 Curves 113 4-9 Sample Problem SP4-1 114 4-10 Isometric Sketching 115 4-11 Sample Problem SP4-2 116 4-12 Exercise Problems 117 4-13 Oblique Sketches 119 4-14 Exercise Problems 120 4-15 Perspective Sketches 122 4-16 Lettering 123 4-17 Exercise Problems 125

Chapter 5 - Orthographie Views 125

5-1 Introduction 129 5-2 Three Views of an Object 129 5-3 Visualization 130 5-4 Exercise Problems 132 5-5 Hidden Lines 133 5-6 Hidden Line Conventions 133 5-7 Drawing Hidden Lines 134 5-8 Exercise Problems 136 5-9 Precedenceof Lines 138 5-10 Slanted Surfaces 138 5-11 Projection Between Views 139 5-12 Sample Problems SP5-1 140 5-13 Compound Lines 141 5-14 Sample Problem SP5-2 141 5-15 Oblique Surfaces 143 5-16 Sample Problem SP5-3 144 5-17 Exercise Problems 145 5-18 Rounded Surfaces 147 5-19 Sample Problem SP5-4 148 5-20Holes 148 5-21 Holes in Slanted Surfaces 150 5-22 Exercise Problems 153 5-23Cylinder 156 5-24 Sample Problem SP5-5 156 5-25 Cylinders with Slanted and Rounded

Surfaces 157 5-26 Sample Problems SP5-6 158 5-27 Drawing Conventions and Cylinders 159 5-28 Exercise Problems 160

5-29 Irregulär Surfaces 162 5-30 Sample Problem SP5-7 162 5-31 Hole Callouts 163 5-32 Castings 165 5-33 Sample Problem SP5-8 167 5-34 Exercise Problems 169 5-35 Thin-Walled Objects 171 5-36 Sample Problem SP5-9 172 5-37 Intersections 173 5-38 Sample Problem SP5-10 173 5-39 Sample Problem SP5-11 175 5-40 Sample Problem SP5-12 175 5-41 Exercise Problems 178

Chapter 6 - Sectional Views 197

6-1 Introduction 197 6-2 Cutting Plane Lines 199 6-3 Section Lines 202 6-4HATCH 203 6-5 Sample Problem SP6-1 206 6-6 Styles of Section Lines 207 6-7 Sectional View Location 207 6-8 Holes in Sections 208 6-9 Exercise Problems 209 6-10 Offset Sections 210 6-11 Multiple Sections 210 6-12 Aligned Sections 211 6-13 Drawing Conventions in Sections 212 6-14 Half, Partial, and Broken-Out Sectional

Views 212 6-15 Removed Sectional Views 214 6-16Breaks 214 6-17 Sectional Views of Castings 215 6-18 Exercise Problems 216

Chapter 7 - Auxiliary Views 227

7-1 Introduction 227 7- 2 Projection Between Normal and Auxiliary

Views 228 7-3 Sample Problem SP7-1 231 7-4 Transferring Lines Between Views 232 7-5 Sample Problem SP7-2 233 7-6 Projecting Rounded Surfaces 233 7-7 Sample Problem SP7-3 233 7-8 Projecting Irregulär Surfaces 234 7-9 Sample Problem SP7-4 235 7-10 Sample Problem SP7-5 237 7-11 Exercise Problems 238

CONTENTS xi

7-12 Partial Auxiliary Views 239 7-13 Sectional Auxiliary Views 240 7-14 Auxiliary Views of Oblique Surfaces 240 7-15 Secondary Auxiliary Views 241 7-16 Sample Problem SP7-6 243 7-17 Secondary Auxiliary View of an Ellipse 244 7-18 Exercise Problems 245

Chapter 8 - Dimensioning 257

8-1 Introduction 257 8-2 Linear Drawing Units 257 8-3 Angular Drawing Units 258 8-4 Dimensioning Terminology and Conventions

258 8-5 Dimensioning with AutoCAD 260 8-6 Horizontal Dimensions 260 8-7 Horizontal Dimension Variables 261 8-8 Horizontal Dimensions for Metrie Units 262 8-9 Variations for Horizontal Dimensions 263 8-10 Vertical Dimensions 265 8-11 Locating Dimensions 266 8-12 Sample Problem SP8-1 266 8-13 Exercise Problems 268 8-14 Aligned Dimensions 271 8-15 Angular Dimensions 271 8-16 Holes 273 8-17 Exercise Problems 277 8-18 Radii Dimensions 280 8-19 Fillets and Rounds 281 8-20 Rounded Shapes (Internal) 281 8-21 Rounded Shapes (External) 282 8-22 Irregulär Surfaces 282 8-23 Polar Dimensions 285 8-24Chamfers 285 8-25 Knurling 286 8-26 Keys and Keyseats 287 8-27 Symbols and Abbreviations 287 8-28 Symmetry and Centerline 288 8-29 Dimensioning to Points 288 8-30 Coordinate Dimensions 288 8-31 Sectional Views 290 8-32 Editing Dimensions 290 8-33 Orthographie Views 290 8-34 Exercise Problems 291

Chapter 9 - Tolerancing 303

9-1 Introduction 303 9-2 Direct Tolerance Methods 303

xii CONTENTS

9-3 Tolerance Expressions 304 9-4 Understanding Plus and Minus Tolerances 304 9-5 Creating Plus and Minus Tolerances Using

AutoCAD 305 9-6 Limit Tolerances 306 9-7 Creating Limit Tolerances Using AutoCAD 306 9-8 Angular Tolerances 307 9-9 Exercise Problems 308 9-10 Standard Tolerances 310 9-11 Double Dimensioning 310 9-12 Chain Dimensions and Baseline Dimen

sions 311 9-13 Tolerance Studies 312 9-14 Exercise Problems 313 9-15 Rectangular Dimensions 314 9-16 Hole Locations 314 9-17 Choosing a Shaft for a Toleranced Hole 315 9-18 Sample Problem SP9-1 316 9-19 Sample Problem SP9-2 316 9-20 Exercise Problems 317 9-21 Standard Fits (Metrie Values) 318 9-22 Nominal Sizes 318 9-23 Hole and Shaft Bases 320 9-24 Sample Problem SP9-3 320 9-25 Standard Fits (Inch Values) 320 9-26 Sample Problem SP9-4 321 9-27 Preferred and Standard Sizes 321 9-28 Surface Finishes 322 9-29 Surface Control Symbols 325 9-30 Exercise Problems 326

Chapter 10 - Geometrie Tolerances 333

10-1 Introduction 333 10-2 Tolerances of Form 334 10-3Flatness 334 10-4 Straightness 334 10-5 Straightness (RFS and MMC) 335 10-6 Circularity 337 10-7 Cylindricity 338 10-8 Applying Geometrie Tolerances Using

AutoCAD 338 10-9 Sample Problem SP10-1 340 10-10 Exercise Problems 340 10-11 Tolerances of Orientation 343 10-12 Datums 343 10-13 Perpendicularity 343 10-14 Parallelism 344 10-15 Angularism 345 10-16 Exercise Problems 345

10-17 Profiles 347 10-18 Runouts 348 10-19 Positioning Tolerances 349 10-20 Virtual Condition 350 10-21 Floating Fasteners 351 10-22 Sample Problem SP10-2 352 10-23 Sample Problem SP10-3 352 10-24 Fixed Fasteners 353 10-25 Sample Problem SP10-4 354 10-26 Exercise Problems 355

Chapter 11 - Threads and Fasteners 365

11-1 Introduction 365 11-2 Thread Terminology 365 11-3 Thread Callouts (Metrie Units) 365 11-4 Thread Callouts (English Units) 366 11-5 Thread Representations 367 11-6 Orthographie Views of Internal Threads 372 11-7 Sectional Views of Internal Threads 372 11-8 Typesof Threads 373 11-9 How to Draw an Extemal Square Thread 374 11-10 How to Draw an Internal Square Thread 375 11-11 How to Draw an Extemal Acme Thread 375 11-12 Exercise Problems 377 11-13 Bolts and Nuts 378 ll-14Screws 378 11-15 Studs 378 11-16 HeadShapes 379 11-17 Nuts 382 11-18 Sample Problem SP11-1 384 11-19 Sample Problem SP11-2 385 11-20 Exercise Problems 386 11-21 Standard Screws 387 11-22 Set Screws 388 ll-23Washers 389 11-24 Keys 390 11-25 Rivets 390 11-26 Springs 392 11-27 Exercise Problems 394

Chapter 12 - Working Drawings 401

12-1 Introduction 401 12-2 Assembly Drawings 402 12-3 Drawing Formats 404 12-4 Tide Block 405 12-5 Revision Block 406 12-6 Tolerance Blocks 407

* CONTENTS xiii

12-7 Release Block 407 12-8 Parts List (Bill of Materials) 408 12-9 Detail Drawings 409 12-10 First Angle Projection 410 12-11 Drawing Notes 411 12-12 Design Layouts 411 12-13 Sample Problem SP12-1 412 12-14 Exercise Problems 416

Chapter 13 - Gears, Bearings, and Cams 431

13-1 Introduction 431 13-2 Typesof Gears 431 13-3 Gear Terminology - Spur 431 13-4 Spur Gear Drawings 433 13-5 Sample Problem SP13-1 434 13-6 Sample Problem SP13-2 436 13-7 Sample Problem SP13-3 438 13-8 Selecting Spur Gears 438 13-9 Center Distance Between Gears 438 13-10 Sample Problem SP13-4 438 13-11 Combining Spur Gears 441 13-12 Gear Terminology - Bevel 443 13-13 How to Draw Bevel Gears 444 13-14 Worm Gears 445 13-15 Helical Gears 447 13-16 Racks 448 13-17 Ball Bearings 449 13-18 Sample Problem SP13-5 449 13-19 Bushings 451 13-20 Sample Problem SP13-6 452 13-21 Cam Displacement Diagrams 453 13-22 Cam Motions 454 13-23 Cam Followers 456 13-24 Sample Problem SP13-7 457 13-25 Exercise Problems 461

Chapter 14 - Fundamentals of 3D Drawing 463

14-1 Introduction 463 14-2 World Coordinate System (WCS) 463 14-3 ELEV 465 14-4 3D FACE 466 14-5 3D OBJECTS 467 14-6 Simple Surface Shapes 474 14-7 Exercise Problems 475 14-8 User Coordinate System (UCS) 479

14-9 Orthographie Views 485 14-10 Sample Problem SP14-1 493 14-11 3DDimensions 495 14-12 Exercise Problems 497

Chapter 15 - Surface Modeling 507

15-1 Introduction 507 15-2RULESURF 507 15-3 REVSURF 508 15-4TABSURF 510 15-5 3DMESH 511 15-6 3DPoly 512 15-7 Sample Problem SP15-1 513 15-8 Exercise Problems 515 15-9 Holes 516 15-10 Cutouts 519 15-11 Slots 521 15-12 Fasteners 522 15-13 3D Blocks 524 15-14 Sample Problem SP15-2 525 15-15 Exercise Problems 531

Chapter 16 - Solid Modeling 537

16-1 Introduction 537 16-2 Primitives 537 16-3 SOLUNION 543 16-4SOLSUB 543 16-5 SOLSEP 546 16-6 Sample Problem SP16-1 546 16-7 Sample Problem SP16-2 547 16-8 Exercise Problems 550 16-9 SOLEXT 552 16-10 SOLIDIFY 553 16-11 SOLREV 554 16-12 MOVEOBJECT 554 16-13 Exercise Problems 556 16-14 SOLCHAM 558 16-15 Slanted Surfaces 558 16-16 Compound Edges 559 16-17 Oblique Surfaces 561 16-18 SOLFTL 561 16-19 Rounded Surfaces 561 16-20 Cylinders 562 16-21 Exercise Problems 564 16-22 Irregulär Surfaces 565 16-23 Castings 565 16-24 Sectional Views - SOLCUT 567 16-25 Fasteners 567

XIV CONTENTS

16-26 Intersections 567 16-27 Exercise Problems 570

Chapter 17 - Design Applications 579

17-1 Introduction 579 17-2 Units 579 17-3 AME System Variables 580 17-4 SOLAREA 580 17-5 SOLFEAT 581 17-6 SOLLIST 582 17-7 SOLMASSP 583 17-8 SOLMAT 584 17-9SOLUCS 585 17-10 SOLWIRE and SOLMESH 586 17-11 Exercise Problems 586 17-12 Descriptive Geometry 587 17-13 Exercise Problems 592

Appendix 601

A-l PROMET Settings 601 A-2 American Standard Clearance Locational

Fits 602 A-3 American Standard Running and Sliding

Fits 603 A-4 American Standard Transition Locational

Fits 604 A-5 American Standard Interference Locational

Fits 605 A-6 American Standard Force and Shrink Fits 606 A-7 Preferred Clearance Fits - Cylindrical Fits

(Hole Basis) 607 A-8 Preferred Transition and Interference Fits -

Cylindrical Fits (Hole Basis) 608 A-9 Preferred Clearance Fits - Cylindrical Fits

(Shaft Basis) 609 A-10 Preferred Transition and Interference Fits -

Cylindrical Fits (Shaft Basis) 610 A-l 1 American National Standards Type A Piain

Washer 611 A-l2 American National Standard Helical Spring

LockWashers 612 A-l3 American National Standard Internal-External

Tooth Lock Washers 613 A-14 British Standard Bright Metal Washers -

Metrie Series 614 A-l5 American National Standard and Unified

Square Bolts 615 A-l6 American National Standard and Unified

Standard Hex Head Screws 616 A-17 Coarse-Thread Series, UNC, UNRC, and

NC - Basic Dimensions 617 A-18 Fine-Thread Series, UNC, UNRC, and

NC - Basic Dimensions 618 A-l9 American National Standard General-Purpose

Acme Screw Thread Form - Basic Dirnen sions 619

A-20 60-Degree Stub Threads 619 A-21 American National Standard Slotted 100° Rat

Countersunk Head Machine Screws 620 A-22 American National Standard

Slotted Truss Head Machine Screws 621 A-23 American National Standard Piain and Slotted

Hexagon Head Machine Screws 622 A-24 Slotted Round Head Machine Screws 623 A-25 American National Standard Square Head Set

Screws 624 A-26 American National Standard Square Head

Set Screws 625 A-27 American National Standard Slotted Headless

Set Screws 626 A-28 Lengths for Threaded Fasteners 627 A-29 Wire and Sheet Metal Gages 627 A-30 American National Standard Square and

Hexagon Machine Screw Nuts 628 A-31 Standard Twist Drill Sizes (Inches) 629 A-32 Standard Twist Drill Sizes (Millimeters) 629 A-33 File 630 A-34Draw 631 A-35 Assist 632 A-36 Construction 632 A-37 Modify 633 A-38 Settings 633 A-39View 634 A-40Render 634 A-41 Model 635

Index 637