Machine Drawing

(avery) #1
20.2.2 Working Assembly Drawings 392
20.2.3 Detailed Drawings and Manufacturing Methods 392
20.3 Example 393
20.3.1 Petrol Engine Connecting Rod 393

21 Computer Aided Draughting 397


21.1 Introduction 397
21.2 Overview 397
21.3 Required Equipment 397
21.3.1 Computer 397
21.3.2 Terminal 398
21.3.3 Keyboard 398
21.3.4 Cathode Ray Tube (CRT) 398
21.3.5 Plotters 398
21.3.6 Printers 398
21.3.7 Digitizers 398
21.3.8 Locators and Selectors 398
21.4 Display Technology 398
21.4.1 Plotting the Drawings 399
21.5 Basics of Operating System 399
21.6 Starting AutoCAD 399
21.6.1 Invoking AutoCAD Commands 400
21.6.2 Interactive Techniques 400
21.7 Planning for a Drawing 402
21.7.1 Co-ordinate System 402
21.7.2 Basic Geometric Commands 403
21.7.3 Drawing Entity-POINT 403
21.7.4 Drawing Entity-LINE 404
21.7.5 Drawing Entity-ELLIPSE 405
21.7.6 Drawing Entity-POLYGON 405
21.7.7 Drawing Entity-RECTANGLE 406
21.7.8 Drawing Entity-CIRCLE 406
21.7.9 Drawing Entity–ARC 407
21.8 Object Selection 407
21.8.1 Edit Commands 408
21.8.2 Zoom Command 409
21.8.3 Cross-hatching and Pattern Filling 410
21.8.4 Utility Commands 410
21.9 Types of Modelling 411
21.9.1 2D Wire Frame 411
21.9.2 3D Wire Frame 411
21.9.3 Surface Modelling 411
21.9.4 Solid Modelling 411
21.10 View Point 412
21.10.1 V-point Co-ordinates View(s) Displayed 413
21.11 View Ports 413
21.12 Creation of 3D Primitives 414
21.12.1 To Draw a Cylinder 414

xx Machine Drawing

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