Introduction to AutoCAD 2004: 2D and 3D Design [1st edition] 0750661763, 9780750661768

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An Introduction to AutoCAD 2004: 2D and 3D Design

An Introduction to AutoCAD 2004: 2D and 3D Design

Alf Yarwood

AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Newnes is an imprint of Elsevier

Newnes An imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 200 Wheeler Road, Burlington, MA 01803 First published 2004 Copyright © 2004, Alf Yarwood. All rights reserved The right of Alf Yarwood to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publisher Permissions may be sought directly from Elsevier’s Science and Technology Rights Department in Oxford, UK. Phone: (⫹44) (0) 1865 843830; fax: (⫹44) (0) 1865 853333; e-mail: [email protected]. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’

British Library Cataloguing-in-Publication Data Yarwood, A. An introduction to AutoCAD 2004 : 2D and 3D design 1. AutoCAD (Computer file) 2. Computer-aided design I. Title 620'.0042'02855369 Library of Congress Cataloguing-in-Publication Data A catalogue record for this book is available from the Library of Congress ISBN 0 7506 61763 For information on all Newnes publications visit our website at http://books.elsevier.com Typeset by Integra Software Services Pvt. Ltd, Pondicherry, India www.integra-india.com Printed and bound in Great Britain

Contents

Preface Acknowledgements

xiii xiv

1 Introduction Aims of this chapter The mouse as a digitiser Terms used throughout the book Opening AutoCAD 2004 Calling tools in AutoCAD 2004 The A3_template.dwt The AutoCAD coordinate system Examples of elementary drawings First example – with Line and Circle tools Second example – with Line and Ellipse tools Third example – with the Line tool Fourth example – with the Circle tool Fifth example – with the Arc tool Making use of the SNAP and ORTHO buttons The Active Assistance dialog Calling Help with the F1 key The Erase tool – example Undo and Redo tools Regen Saving drawings Revision tips Exercises

1 1 1 2 3 5 5 5 6 6 8 9 9 9 10 11 11 12 13 13 13 14 15

2 The Zoom tools Aims of this chapter The Zoom tools The variety of zooms The Aerial View window The Pan tool The wheel of a type of mouse Revision tips Exercises

17 17 17 18 21 22 22 23 23 v

vi

Contents

3 Templates Aims of this chapter A template for use with this book Setting Limits Setting Units Setting Grid Setting Snap Setting Text Style Setting Dimension Style Setting Layers Saving the template Another template Revision tips

24 24 24 24 25 25 26 26 27 30 32 33 35

4 Accuracy when drawing Aims of this chapter The Circle and Arc tools First example – Circle – the Ttr response Second example – the Arc tool prompts Constructions using absolute coordinates First example Second example Constructions involving relative coordinate entry First example – relative coordinate entry Second example – relative coordinate entry Tracking Example – tracking Object Snaps Example – using osnap abbreviations AutoSnap Polar tracking An example of a drawing involving decimals Snap, Ortho and Grid Revision tips Exercises

36 36 36 36 37 37 38 38 39 39 40 41 41 41 43 44 45 45 46 47 47

5 More tools from the Draw toolbar Aims of this chapter The Polyline tool First example – Polyline – Width Second example – Polyline – Arc Third example – Polyline – Circle Fourth example – Polyline – Arrows Fifth example – Polyline – Fill The Construction Line tool Example – Construction Line The Polygon tool Examples – Polygons

51 51 51 51 52 53 53 54 55 56 57 58

Contents

The Rectangle tool Examples – Rectangle tool The Ellipse tool Examples – Ellipse The set variable PELLIPSE The Revcloud tool Example – Revcloud The Spline tool The Point tool Revision tips Exercises

6 The Modify tools Aims of this chapter The Modify toolbar The Copy Object tool First example – Copy Object – single copy Second example – Copy Object – multiple copy The Mirror tool First example – Mirror The variable MIRRTEXT The Offset tool First example – Offset Other examples – Offset The Array tool First example – Rectangular array Second example – Polar array The Move tool The Rotate tool Examples – Rotate The Scale tool Examples – Scale The Stretch tool Examples – Stretch The Trim tool First example – Trim No extend Second example – Trim Extend The Extend tool Examples – Extend The Break tools Examples – Break The Chamfer tool Examples – Chamfer The Fillet tool Examples – Fillet Revision tips Exercises

vii

59 59 60 61 62 62 62 63 64 65 65

70 70 70 70 71 71 72 72 73 73 73 74 74 74 75 77 78 78 79 79 79 79 80 80 81 82 82 83 84 85 85 86 86 87 87

viii

Contents

7 Dialogs, menus, text Aims of this chapter Dialogs The Options dialog Warning windows Menus Some sub-menus from drop-down menus Some right-click menus Text First example – Multiline Text Second example – Single line text Text fonts Checking spelling First example – the ddedit tool Second example – the Check Spelling tool The variable TEXTFILL Text symbols Revision tips Exercises

91 91 91 91 92 92 94 95 97 97 98 99 99 100 101 102 102 103 104

8 Layers and other features Aims of this chapter Layers Icons in the Layers popup list Limit to number of layers in a drawing The Options dialog Screen colours Lineweights The Polyline Edit tool Examples – Edit Polyline The Multiple option of Edit Polyline Express tools Grips Examples – Grips Revision tips

105 105 105 106 106 107 107 108 109 109 110 111 111 112 113

9 The DesignCenter and MDE Aims of this chapter The AutoCAD DesignCenter Dragging drawings from the DesignCenter Previews The Tree View Toggle icon The Multiple Document Environment (MDE) The Properties palette Revision tips Exercises

114 114 114 115 117 117 118 118 121 121

10 Types of technical drawings Aims of this chapter Orthographic projection

123 123 123

Contents

Number of views in an orthographic projection Rules for orthographic projections Lines in technical drawings Examples of orthographic projections Isometric projection Isoplanes Examples of isometric drawings Revision tips Exercises

ix

124 126 126 127 127 128 130 133 134

11 Hatching Aims of this chapter The Hatch tool The parts of the Hatch Boundary and Fill dialog Other hatch palettes Other sub-dialogs Examples of hatching Hatching from the command line The hatching of sections in technical drawings Revision tips Exercises

138 138 138 138 138 138 139 146 146 147 148

12 Dimensioning Aims of this chapter The Dimension toolbar Examples of adding dimensions using the tools The meanings of the symbols Dimensioning from the command line Dimensions are associative Revision tips Exercises

151 151 151 151 158 160 162 163 163

13 Blocks and Inserts Aims of this chapter The Make Block tool Example – making a block The Insert Block tool Written blocks (wblocks) Example – constructing a written block Example – insertion of blocks The flyout from the Insert Block tool icon External references (Xrefs) Example – external references Inserting raster images Example – Image tool Attributes Example – Attributes Editing the attribute Revision tips Exercises

165 165 165 166 167 169 169 171 172 172 172 174 174 176 176 178 180 180

x Contents

14 Building drawing Aims of this chapter Types of building drawing First example – drawings for 63 Pheasant Drive Construction of floor layout drawings Hatching Exercises

183 183 183 183 183 184 185

15 Edit tools, DXF and EPS files Aims of this chapter Example of using the Edit tools First example – Copy Second example – Copy Link Third example – Paste Fourth example – Encapsulated Postscript file OLE (Object Linking and Embedding) DXF files Example – DXF file Revision tips Exercises

190 190 190 190 191 191 192 193 193 195 196 196

16 The Solids tools Aims of this chapter 3D Solid models 3D Views The UCS The Solids toolbar Examples of using the Solids tools The UCS The UCS icon Some examples of using the UCS Revision tips Exercises

198 198 198 198 199 200 200 206 207 208 211 211

17 More advanced 3D models Aims of this chapter The Extrude tool First example – Extrude Second example – Extrude Third example – Extrude Fourth example – Extrude The Revolve tool First example – Revolve Second example – Revolve Third example – Revolve The Slice tool Example – Slice The Section tool Example – Section

215 215 215 215 217 217 220 222 222 223 224 225 225 226 226

Contents

The Setup Profile tool First example – Setup Profile Second example – Setup Profile Revision tips Exercises

xi

227 227 229 230 232

18 Viewports Aims of this chapter Viewports The variables UCSFOLLOW and UCSVP Example of constructions in viewports First example – Four: Equal setup Second example – Three: Left setup Third example – Four: Left Example – moving viewports Revision tips Exercises

237 237 237 238 239 239 240 242 242 243 244

19 Rendering Aims of this chapter Introduction Rendering options The Render tools Rendering lighting Rendering without adding lights Types of rendering lights Lighting icons Examples of rendering Revision tips Exercises An example of using Paper Space

247 247 247 247 248 248 248 249 251 251 257 257 260

20 3D surface models Aims of this chapter Introduction Examples of models using surface tools First example – 3D Face Second example – 3D Face Third example – Box Fourth example – Wedge Fifth example – Pyramid Sixth example – Cone Seventh example – Sphere Eighth example – Dome and Dish Ninth example – Torus Tenth example – Edge Surface Eleventh example – Revolved Surface Twelfth example – Tabulated Surface Thirteenth example – Ruled Surface

263 263 263 263 263 264 265 266 266 267 267 268 269 270 271 271 272

xii

Contents

Revision notes Exercises Rendering surface models

273 273 277

21 More 3D solid models Aims of this chapter First example Second example Third example Fourth example Fifth example Exercises

278 278 278 281 283 287 289 291

22 Internet tools Aims of this chapter Emailing drawings Example – creating a web page Browsing the Web The eTransmit tool

296 296 296 296 299 300

23 Design and AutoCAD 2004 Ten reasons for using AutoCAD The place of AutoCAD 2004 in designing The design chart Enhancements in AutoCAD 2004 System requirements for running AutoCAD 2004

302 302 302 303 304 305

Appendix A Printing and plotting Introduction An example of a printout

306 306 307

Appendix B List of tools Introduction 2D tools 3D tools Internet tools

310 310 310 314 315

Appendix C Some set variables Introduction Some of the set variables

316 316 316

Appendix D Computing terms

318

Index

323

Preface

The purpose of writing this book is to produce a text suitable for those in Further and/or Higher Education who are required to learn how to use the computer aided design (CAD) software package AutoCAD® 2004. The book’s contents are also suitable for those in industry wishing to learn how to construct technical drawings with the aid of AutoCAD 2004 and those who, having used previous releases of AutoCAD, wish to update their skills in the use of AutoCAD. The chapters dealing with two-dimensional (2D) drawing will also be suitable for those wishing to learn how to use AutoCAD LT 2004, the 2D version of this latest release of AutoCAD. Many readers using AutoCAD 2002 will find this book’s contents largely suitable for use with that version of AutoCAD, although AutoCAD 2004 has many new enhancements over AutoCAD 2002 (see Chapter 23). The contents of the book are basically a carefully graded course of work, consisting of chapters giving explanations and examples of methods of constructions, followed by exercises to allow the reader to practise what has been learned in each chapter. The first set of chapters are concerned with constructing technical drawing in two dimensions (2D). These early chapters are followed by chapters detailing the construction of three-dimensional (3D) solid model drawings and rendering them. The two final chapters describe the Internet tools of AutoCAD 2004 and AutoCAD’s place in the design process. The book finishes with four appendices – printing and plotting, a list of tools with their abbreviations, a list of some of the set variables upon which AutoCAD 2004 is based, and a final appendix describing common computing terms. AutoCAD 2004 is a very complex CAD software package. A book of this size cannot possibly cover the complexities of all of the methods for constructing 2D and 3D drawings available when working with this CAD software. However, it is hoped that by the time the reader has worked through the contents of the book, he/she will be sufficiently skilled with the methods given for producing drawings using the software to be able to go on to more advanced constructions with its use and will have gained an interest in the more advanced possibilities available when using AutoCAD for the construction of 2D technical drawings and 3D solid model drawings and the sharing of those drawings via the Internet. Alf Yarwood Salisbury 2004 xiii

Acknowledgements

Alf Yarwood wishes to acknowledge with grateful thanks the permissions granted by Simon Lake, Product Development Director of Pearson Education, to reproduce parts of the glossaries contained in this book from past publications of his books published by Pearson Education.

Registered Trademarks The following are registered in the US Patent and Trademark Office by Autodesk Inc.: Autodesk®, AutoCAD®. Windows® is a registered trademark of the Microsoft Corporation. Alf Yarwood is a member of the Autodesk Advanced Developer Network and a Master Developer with Autodesk Ltd.

xiv

CHAPTER 1

Introduction

Aims of this chapter The contents of this chapter are designed to introduce the following topics: The mouse as a digitiser. The AutoCAD coordinate system. Opening AutoCAD 2004 and the AutoCAD 2004 window. Methods of calling tools. Using the Line, Circle, Arc, Erase, Undo, Redo and Regen tools. Toggling with the function keys. Help. The A3_template.dwt as the basis for drawings throughout the book. 9. Simple drawing methods based on the coordinate system. 10. The Active Assistance dialog and Help. 11. Saving drawings. 1. 2. 3. 4. 5. 6. 7. 8.

The mouse as a digitiser

Pick button

Return button

Wheel

Fig. 1.1 An optical mouse

Throughout this book the type of digitiser in use will be a two-button mouse. Other digitisers can be used with AutoCAD 2004 – pucks working with tablets for example. Fig. 1.1 shows one type – an optical mouse. The wheel of such a mouse is of value when working in AutoCAD 2004, in that zooming in or out can be effected by turning the wheel of the mouse. Holding and moving the wheel down allows panning of the screen (see page 22). The following terms are used in this book to describe actions which can be taken with a mouse: Left-click: Place the cursor under mouse control onto a feature and press the Pick button of the mouse. Right-click: Move the cursor under mouse control onto a feature and press the Return button of the mouse. Click: Has the same meaning as left-click. Double-click: Place the cursor under mouse control onto a feature and press the Pick button of the mouse twice in rapid succession. Drag: Move the cursor under mouse control, hold down the Pick button and move the mouse. The feature moves with the mouse movement. 1

2 An Introduction to AutoCAD 2004: 2D and 3D Design

Drag and drop: Drag a feature into a new position and release the mouse button when the feature is in the required new position. Pick: Move the cursor onto a feature and press the Pick button of the mouse. Note

The terms above are shown in italics throughout the book.

Terms used throughout the book Note

Terms shown in italics are shown in italics throughout the book. Cursor: Several types of cursor will be seen when using AutoCAD 2004 such as those shown in Fig. 1.2. Move the mouse, and the cursor in action moves as the mouse is moved.

Cursor arrow Pick box

Fig. 1.2 A few of the cursors seen in AutoCAD 2004

Cursors for re-sizing toolbars

Docked: A feature in a position right up against the edge of the screen or against another toolbar. Default: The name given to the settings or parameters of an application as set when the software is first purchased. Dialog: A window in which settings may be made (Fig. 1.3).

Fig. 1.3 A dialog

Introduction

Fig. 1.4 A drop-down menu

Fig. 1.5 A flyout

3

Drop-down menu: A menu which appears with a click on a name in the menu bar of AutoCAD 2004 (Fig. 1.4). Enter: Type the given word or letters at the keyboard. Entity: Has the same meaning in AutoCAD 2004 as has the word object. Esc: The Esc key of the keyboard. In AutoCAD 2004 pressing the Esc key has the effect of cancelling the current action taking place. Flyout: Some tool icons have a small arrow in the bottom right-hand corner of the icon. When the cursor is placed onto an icon with an arrow and the Pick button of the mouse is held down a flyout appears (Fig. 1.5). Icons: A feature in all Windows applications – a small item of graphics representing a tool or a function of the software in use (Fig. 1.6). Objects: Individual lines, circles, etc. as drawn in AutoCAD 2004. When objects are joined together as groups or as blocks, the whole group will be treated as an object. Pick box: An adjustable square at the intersection of the cursors and also associated with picking features of a construction (see Fig. 1.2). Return: Press the Return or Enter key of the keyboard. Usually, but not always, has the same result as a right-click – i.e. pressing the Pick button of the mouse. Select: Has the same meaning as pick. Tab key: The key usually on the left-hand side of the keyboard which carries two arrows. Tool: The name given to a command in recent releases of AutoCAD. Tool tip: The name of the tool represented by an icon, which appears when the cursor under mouse control is placed onto a tool icon (Fig. 1.6).

Opening AutoCAD 2004 There are two methods of loading AutoCAD 2004 from the Windows desktop icons: 1. Double-click on the AutoCAD 2004 shortcut icon (Fig. 1.7). 2. Right-click on the shortcut icon and from the menu which then appears, click on Open. Fig. 1.6 A tool icon and its tooltip

Fig. 1.7 The AutoCAD 2004 shortcut icon

The AutoCAD 2004 window opens (Fig. 1.8). Fig. 1.8 names the parts of the window. Normally six toolbars are included in the opening AutoCAD 2004 window unless the window is configured otherwise: Standard: Docked against the left side of the upper edge of the window. Styles: Docked against the right side of the upper edge of the window. Layers: Docked against the lower edge of the Standard toolbar. Properties: Docked against the lower edge of the Styles toolbar. Draw: Docked against the left-hand edge of the window. Modify: Docked against the Draw toolbar, but in some cases docked against the right-hand edge of the window.

4 An Introduction to AutoCAD 2004: 2D and 3D Design

Fig. 1.8 The AutoCAD 2004 window

The window also includes: Title bar: Includes the name AutoCAD 2004 and the name of the drawing being constructed, provided it has been saved. A drawing name is not included in Fig. 1.8. Menu bar: A click on a name in the menu bar brings the drop-down menu associated with that name on screen. Close, Maximise and Minimise buttons: A click on the Close button closes the AutoCAD 2004 window. A click on the Minimise button closes the AutoCAD 2004 window, but it can be recalled from the AutoCAD 2004 icon bar in the Task bar at the bottom of the screen. A click on the Maximise button either enlarges or reduces the size of the window. Command window: Is a window in its own right and can be moved if required around the screen. Tool commands and prompt entries are made in the command window by typing at the computer’s keyboard. Status bar: Includes a number of buttons SNAP, GRID, etc. Coordinate figures in x,y,z numbers appear at the left-hand end of the bar. When a tool is called, its action is displayed in a sentence displacing the coordinate numbers. Model and Layout tabs: A click on one of these tabs takes the window into Model Space (the Model tab) or Paper Space (a Layout tab). When AutoCAD 2004 is opened its window will appear in Model Space format. UCS icon: Shows the directions of the X- and Y-axes. Cursor hairs: These show a pick box at the intersection of the cursor hairs. As the mouse moves, the pick box and the cursors move in sympathy with the mouse movement. Grid dots: If Grid is set on, a series of dots appear in the drawing area.

Introduction

5

Calling tools in AutoCAD 2004 Constructions in AutoCAD 2004 are undertaken with the use of tools. These used to be called ‘commands’ in early versions of AutoCAD and the term ‘command’ may well be still in use with some operators. In this book the term ‘tool’ is used in preference to ‘command’. Tool icons are held in toolbars. Fig. 1.9 shows the tools in the Draw toolbar which is usually docked against the left-hand edge of the AutoCAD 2004 window. A click on a tool icon in a toolbar calls the tool into action. Tools can also be called from drop-down menus. The Draw tools can be called from the Draw drop-down menu (Fig. 1.10). Tools can be ‘called’ for use in four different ways. Most AutoCAD operators when they have acquired a reasonable degree of skill use a mixture of these four methods depending upon the action required at the moment. Thus to call the Line tool are four methods: 1. Click on the Line tool icon in the Draw toolbar. 2. Click on the name Line in the Draw drop-down menu. 3. At the command line in the command window enter line, followed by a right-click. 4. At the command line enter l (the abbreviation for Line), followed by a right-click. See Fig. 1.11. Fig. 1.9 The Draw toolbar showing all tool icons

Note

If a tool is called with a click on its tool icon in the Draw toolbar, a statement appears in the status bar describing the action of the tool. This is shown for Line in Fig. 1.11. If line, or its abbreviation l is entered at the command line, this statement does NOT appear in the status bar.

The A3_template.dwt Drawings throughout this book have mostly been constructed in an AutoCAD template saved as A3_template.dwt. A description of the method of constructing this template is given in Chapter 3 (page 24). The files included with AutoCAD 2004 contain large number of different templates. These contain set parameters for the construction of a variety of different types of drawings.

The AutoCAD coordinate system The AutoCAD 2004 drawing area can be regarded as consisting of units, the number of which depend upon settings in the template in use at the time. Any point in the drawing area can be referred to by the number of units horizontally from an origin in terms of X and the number of units vertically from an origin in terms of Y. If the origin of the drawing area is taken as X ⫽ 0 and Y ⫽ 0, this is referred to as x,y ⫽ 0,0. Similarly, any

6 An Introduction to AutoCAD 2004: 2D and 3D Design

point on the screen can be described in terms of x,y giving the exact location of the point in the drawing area. The following rules apply: A comma (,) between the x and y to describe a coordinate point. .x,y ⫽ 33,98 is 33 units horizontally to the right of the origin and 99 units vertically above the origin. .x,y ⫽ ⫺42,53 is 42 units horizontally to the left of the origin and 53 units vertically above the origin. .x,y ⫽ 67,⫺71 is 67 units horizontally to the right of the origin and 71 units vertically below the origin. A third coordinate Z is used when working in three dimensions (3D). It will be seen that the coordinate number shown at the left-hand end of the status bar shows three coordinates, the Z coordinate being the last of the three numbers which are shown in the form of x,y,z. When working in two dimensions (2D), the Z coordinate shows as 0 (Fig. 1.12). Fig. 1.13 shows some x,y coordinate points in the drawing area of the A3_template.dwt. The drawing area of this template is 420 units by 297 units. The size of an A3 sheet is 420 mm by 297 mm. Each coordinate unit in this template can be regarded as being 1 mm in length.

Examples of elementary drawings First example – with Line and Circle tools (Fig. 1.19)

1. Move the mouse until the cursor is placed over the left-hand end of the status bar. After a slight hesitation, a description of what is at that position appears (Fig. 1.14). Fig. 1.10 The tools in the Draw drop-down menu

Fig. 1.11 Calling Line by entering I

Fig. 1.12 The coordinate numbers in the status bar

2. Press the keyboard key F6. The coordinate numbers in the status bar either show or grey-out. Make sure the coordinate numbers are shown (Fig. 1.15). 3. Left-click on the SNAP button in the status bar (Fig. 1.16). If this pushes the SNAP button ‘in’, snap is set on, and as the cursor moves it snaps between snap points. Make sure snap is on (Fig. 1.16).

Introduction 330,295

7

420,290

220,265

10,260 60,220

285,220

170,215

405,190

255,170

25,165

345,150

130,145 335,105

35,100

325,75

110,75

230,30

Fig. 1.13 x,y coordinate points in the AutoCAD 2004 drawing area

420,25 0,0

Fig. 1.14 The description of what is in the left-hand end of the status bar

Fig. 1.15 The coordinate numbers showing clearly in the status bar

Fig. 1.16 Left-click on the SNAP button

Fig. 1.17 The Line tool icon in the Draw toolbar

4. Call the Line tool with a left-click on its tool icon in the Draw toolbar (Fig. 1.17). 5. Move the cursor by moving the mouse until the coordinate numbers show 0,270, and left-click (Fig. 1.19). 6. Move the cursor until the coordinate numbers show 195,270, and leftclick. 7. Continue in this manner following the coordinates shown in Fig. 1.19. When back to 0,270, right-click. A rectangle forms. 8. Left-click on the Circle tool icon in the Draw toolbar (Fig. 1.18). 9. Move the cursor until 30,240 shows in the status bar, and left-click.

8 An Introduction to AutoCAD 2004: 2D and 3D Design 0,270

195,270

30,240

165,240

30,190

165,190

Fig. 1.18 The Circle tool icon from the Draw toolbar Fig. 1.19 First example – Line and Circle tools

0,160

195,160

10. Move the cursor 10 units to the right – until the coordinates show 40,240, and left-click. A circle forms. Repeat for the other three circles as shown in Fig. 1.19. Second example – with Line and Ellipse tools (Fig. 1.21)

Fig. 1.20 The Ellipse tool icon in the Draw toolbar

1. Using the same method as for the first example, construct the outline given in Fig. 1.21 using the Line tool. 2. Call the Ellipse tool with a left-click on its tool icon in the Draw toolbar (Fig. 1.20). 3. Move the cursor under mouse control until the coordinates show 80,130, and left-click. 4. Move the cursor until the coordinates show 280,130, and left-click. 5. Move the cursor until the coordinates show 180,185, and right-click. An ellipse forms. Fig. 1.21 shows the resulting drawing.

Start here 80,210 80,180

280,210 280,180 310,180

180,185

50,180

80,130

50,80 80,80

Fig. 1.21 Second example – Line and Ellipse tools

80,50

280,130

310,80 280,80 280,50

Note

In the two examples given above, the third number in the coordinates showing in the status bar should be ignored.

Introduction

9

Third example – with the Line tool (Fig. 1.22)

Call the Line tool with a click on its tool icon in the Draw toolbar (Fig. 1.17), or by entering line or l at the command line. The command line shows: Command:_line Specify first point: enter 60,230 right-click Specify next point or [Undo]: enter 250,230 right-click Specify next point or [Undo]: enter 250,110 right-click Specify next point or [Close/Undo]: enter 60,110 right-click Specify next point or [Close/Undo]: enter c (for Close) right-click Command: and the rectangle given in Fig. 1.22 is drawn. 60,230

250,230

c (Close)

Fig. 1.22 Third example – with the Line tool

60,110

250,110

Fourth example – with the Circle tool (Fig. 1.23) 0 R8

190,160

Call the Circle tool with a click on its tool icon in the Draw toolbar (Fig. 1.18) or by entering circle or c at the command line. The command line shows: Command:_circle Specify center point for circle or [3P/2P/Ttrr (tan,tan,radius)]: enter 190,160 right-click Specify radius of circle or [Diameter]: enter 80 right-click Command: and the circle given in Fig. 1.23 is drawn.

Fig. 1.23 Fourth example – with the Circle tool

Fifth example – with the Arc tool (Fig. 1.25)

Call the Arc tool with a click on its tool icon in the Draw toolbar (Fig. 1.24), or by entering arc or a at the command line. The command line shows:

Fig. 1.24 The Arc tool icon from the Draw toolbar

Command:_arc Specify start point of arc or [Center]: enter 30,220 right-click Specify second point of arc or [Center/End]: enter 80,250 right-click Specify end point of arc: enter 140,220 right-click Command: right-click (brings the arc sequence back) ARC Command:_arc Specify start point of arc or [Center]: enter 310,220 right-click

10

An Introduction to AutoCAD 2004: 2D and 3D Design

Specify second point of arc or [Center/End]: enter c (for Center) right-click Specify center point of arc: enter 250,160 right-click Specify end point of arc or [Angle/chord Length]: enter 190,220 right-click Command: and the two arcs given in Fig. 1.25 are drawn.

80,250

Fig. 1.25 Examples – with the Arc tool

30,220

140,220 190,220

310,220

250,160

Notes

1. Apart from clicking the appropriate tool icon, entering the tool name or an abbreviation for the tool name, tools from the Draw toolbar can be selected from the Draw drop-down menu (Fig. 1.26). 2. When a tool is called, a sequence of ‘prompts’ appear at the command line. In these prompt sequences, where a prompt starts with a capital letter, entering the capital letter followed by a right-click brings another prompt line associated with that prompt. See the example in the Arc example where a c (for Center) brought up a prompt line asking for the center of the arc. 3. In the remainder of this book when showing prompt sequences and the responses, the terms enter and right-click will not always be used in order to save page space. 4. As well as leaving out these two terms, long sequences of prompts once they have been given and have to be repeated, will be replaced by: [prompts].

Making use of the SNAP and ORTHO buttons

Fig. 1.26 Draw tools can be selected from the Draw drop-down menu

Fig. 1.27 The buttons in the status bar

Frequent use of some of the buttons in the status bar (Fig. 1.27) is advisable to speed up some operations when using AutoCAD 2004. The buttons can be toggled on/off with left-clicks. When a button appears as if pushed in, the relative action is on. When the SNAP button is set on, movements of the mouse can only occur between the snap points as set in

Introduction

11

the template in use. It is sometimes advisable to have SNAP set on and sometimes for it to be set off. The same applies to the ORTHO which when on, allows tools to be used only in strictly vertical or horizontal directions. As skill in the use of AutoCAD increases, so will the other buttons be used as occasion demands. These actions can also be toggled on/off by pressing function keys: F9: F8: F7: F3: F10:

toggles SNAP. toggles ORTHO. toggles GRID. toggles OSNAP. toggles POLAR.

The choice of using the status bar buttons or the function keys will probably vary depending upon the practices the operator develops as his/her skills progress.

The Active Assistance dialog

Fig. 1.28 Opening the Active Assistance dialog from the Help drop-down menu

Left-click on Help in the menu bar. The Help drop-down menu appears (Fig. 1.28). Click on Active Assistance in the menu. Once the dialog is activated by this selection, when a tool is called, an Active Assistance dialog for that tool appears. Fig. 1.29 shows the Active Assistance dialog for the Arc tool.

Fig. 1.29 The Active Assistance dialog for the Arc tool

Calling Help with the F1 key Another method for calling help is by pressing the function key F1. When a tool has been called, if there is some indecision as to how the tool can be used, pressing F1 brings up a Help dialog for that tool. Fig. 1.30

12

An Introduction to AutoCAD 2004: 2D and 3D Design

Fig. 1.30 The Help dialog appearing when F1 is pressed for the Line tool

shows such a dialog brought to screen by pressing F1 when the Line tool is in use. As skill builds in operating AutoCAD 2004, it will probably not be necessary to use either the Active Assistance dialog or to press F1.

The Erase tool – example (Fig. 1.32) Fig. 1.31 The Erase tool icon in the Modify toolbar

If an error is made when constructing a drawing, the Erase tool can be used to delete objects in a drawing. To call the Erase tool, either left-click its tool icon at the top of the Modify toolbar (Fig. 1.31) or enter e at the command line. By far the quickest method is to enter e at the command line. The command line shows: Command: e Select objects: pick one of the lines 1 found Select objects: pick the second line 1 found 2 total Select objects: right-click Command: see Fig. 1.32.

Select objects

Result

Fig. 1.32 The Erase tool – example

Introduction

13

Instead of picking, individual objects to be erased can be windowed. If the window is from top left to bottom right of the objects to be erased, only those objects within the window are deleted. If, however, the window is from bottom right to top left, all objects crossed by the window are deleted. A bottom right to top left window is a crossing window.

Undo and Redo tools Fig. 1.33 The Undo and Redo icons in the Standard toolbar

The Undo and Redo tool icons are in the Standard toolbar which is docked against the menu bar. Fig. 1.33 shows the Undo icon. The Redo tool icon is to the right of the Undo button. A click on the Undo button undoes the last object added to a drawing. Repeated clicks on the button will eventually lead to all objects added during the current session to be undone. The same applies to the Redo button which brings back on screen those objects removed by using Redo. It is far easier to just enter u at the command line for Undo rather than click the icon.

Regen It is occasionally necessary to regenerate the drawing on screen. This will sometimes be when the Zoom tool has been used (see page 17). Regeneration redraws the screen and if a number of arcs or circles are in a drawing forms these into more exact shapes. To make regeneration effective just enter re at the command line.

Saving drawings The purpose of including a series of worked examples in the chapters of this book is to help readers build up an expertise in using AutoCAD 2004. With this in mind, it is advisable to work through the worked examples and also any exercises which end most chapters. The resulting drawings should be saved to a floppy disk, usually in the A: drive of a computer. To save a drawing which has been constructed in AutoCAD 2004:

Fig. 1.34 Selecting Save As . . . from the File drop-down menu

1. Left-click File in the menu bar and in the drop-down menu which appears left-click Save As . . . (Fig. 1.34). The Save Drawing As dialog appears (Fig. 1.35). 2. Place a formatted floppy disk in the A: drive. Then, in the Save in field of the dialog list select 31/2 Floppy (A:). 3. In the File name field enter a suitable file name – in Fig. 1.35 this is Worked example 01. 4. Click the Save button of the dialog. The drawing will be saved to a file name Worked example 01.dwg. The file name extension .dwg is added automatically.

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An Introduction to AutoCAD 2004: 2D and 3D Design

Fig. 1.35 The Save Drawing As dialog

Revision tips 1. Make sure the terms used throughout this book are understood. 2. AutoCAD 2004 can be opened either with a double-click on the AutoCAD 2004 shortcut icon on the Windows desktop or with a rightclick on the icon which brings up a menu – a click on Open in that menu opens AutoCAD 2004. 3. There is another method of opening AutoCAD 2004 not given in this chapter. A click on the Start button in the Windows task bar, followed by another click on All Programs in the menu which appears, followed by a click on AutoCAD 2004 in that menu. This brings up a sub-menu from which AutoCAD can be opened. 4. Tools can be called using any one of four methods – a click on the tool’s tool icon in the appropriate toolbar, a click on the tool name in the appropriate drop-down menu, entering the tool name at the command line or entering an abbreviation for the tool name at the command line. 5. When a tool is called with a click on its tool icon, a statement appears in the status bar stating the action of the tool. 6. Any point in the AutoCAD 2004 drawing area can be referred to as a coordinate point in terms of x,y number. 7. Make full use of the buttons in the status bar, particularly the SNAP and ORTHO buttons. 8. The Active Assistance dialog can be called to screen to give help when any tool is called for use.

Introduction

15

9. Pressing the F1 key when a tool is called, brings a Help dialog for that tool to screen. 10. Use Erase to delete errors made when drawing. Undo and Redo can also be used to immediately remove wrong objects or call them back to screen as needed. 11. Save drawings made in answer to both the worked examples and the exercises in chapters in this book. Use a floppy disk for this, unless you are the only person using the computer.

Exercises 1. Using the Line and Circle tools, construct the drawing given in Fig. 1.36. When completed, save to a file name such as ex01.dwg.

80,240

310,240

190,160

110,210

280,210

R5

0

110,110

280,110 R15 310,80

80,80

Fig. 1.36 Exercise 1

2. Construct the drawing given in Fig. 1.37 using the Line and Circle tools. The x,y coordinate positions of the centres of the circles will require to be calculated before the circles can be drawn.

20 110,240 20

290,240 320,210

80,210

All circles are of radius 10

80,100

Fig. 1.37 Exercise 2

110,70

320,100 290,70

3. Using the Line and Arc tools construct the drawing given in Fig. 1.38.

16

An Introduction to AutoCAD 2004: 2D and 3D Design 155,250 60,220

100,210

210,210

250,220

155,200 155,160 100,150

60,140

210,150

245,140

155,110

Fig. 1.38 Exercise 3

4. Construct the drawing given in Fig. 1.39 using the Line, Arc and Circle tools. R45 R35

185,180

110,180

260,180

135,125

235,125

R40 260,95

Fig. 1.39 Exercise 4

110,50

135,65

235,65

260,50

CHAPTER 2

The Zoom tools

Aims of this chapter The contents of this chapter are designed to introduce the use and importance of the following: 1. The Zoom tools. 2. The Pan tool. 3. The Aerial View window.

The Zoom tools The Zoom tools are among the most frequently used tools when constructing drawings in AutoCAD 2004. These tools allow the smallest area of a drawing to be examined, modified or added to with great accuracy as and when required. There are several methods of calling the Zoom tools: 1. By entering z (for Zoom) at the command line, which then shows: Command: enter z right-click ZOOM Specify corner of window, enter a scale factor (nX or nXP) or [All/ Center/Dynamic/Extents/Previous/Scale/Window] ⬍real time⬎: pick a corner for a real time window Specify opposite corner: pick Command: 2. Toolbars not already in the AutoCAD 2004 window can be brought to the screen with a right-click in any toolbar already on screen, when a menu listing all toolbars appears (Fig. 2.1). A click on Zoom in this list brings the Zoom toolbar to screen. Tools can be selected from the toolbar (Fig. 2.2). 3. With a click on the appropriate Zoom tool icon in the Standard toolbar (docked just beneath the menu bar) – Fig. 2.3.

Fig. 2.1 Bringing the Zoom toolbar on screen

The person operating AutoCAD may decide to use a mixture of these three methods. By far, the quickest method of using Zoom is to enter z at the command line. For the purpose of describing the actions of the Zoom tools an example – the building plan drawing given in Fig. 2.4 – will be used. This drawing has been constructed in an A2 size template. 17

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An Introduction to AutoCAD 2004: 2D and 3D Design

BATH & WC

Landing BEDROOM 2

Fig. 2.2 The Zoom toolbar

Bath

BEDROOM 3

BEDROOM 1

UPPER FLOOR

CLOAKS STUDY

Fig. 2.3 The Zoom tool icons in the Standard toolbar

HALL

KITCHEN

DINING ROOM

LOUNGE

Fig. 2.4 The building plan used as an example for describing the Zoom tools

UTILITY

LOWER FLOOR

The variety of zooms

From the zoom command line, sequence of prompts when Zoom is called by entering z at the command line: All/Center/Dynamic/Extents/Previous/Scale/Window Real time: When Zoom is called by entering z the first prompt asks for a corner of a zoom window. When picked the window’s opposite corner must be picked and the screen shows the area within the window filling the whole of the drawing area. Fig. 2.5 shows the zoom window picked in the drawing, and Fig. 2.6 the resulting zoomed drawing. All: The drawing area reverts to the limits set in the template being used (see page 24). Center: Asks for a centre point to be specified. When picked, the drawing centres around the specified point. Dynamic: A rectangle appears in the AutoCAD drawing area, the size, but not the proportions of which can be changed. A cross appears in the centre of the rectangle. Left-click and the cross changes to an arrow against the right-hand edge of the rectangle. With the arrow in position, dragging alters the size and position of the rectangle. When its size and position are as wished, a right-click zooms the area within the rectangle. Fig. 2.7 shows the drawing on screen with the Dynamic rectangle and Fig. 2.8 the arrow against the right-hand edge of the rectangle. Fig. 2.9 shows the resulting dynamic zoomed window.

The Zoom tools

19

Fig. 2.5 Picking a real time window

Extents: The drawing fills the AutoCAD drawing area. Previous: No matter which zoom is called, the Previous prompt causes the previous zoom to appear. Scale: Entering a figure greater than, or smaller than 1 in digits or decimal form enlarges or reduces the drawing to the given scale figure. Window: Has the same effect as real time.

Fig. 2.6 The result of the real time window of Fig. 2.5

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An Introduction to AutoCAD 2004: 2D and 3D Design

Fig. 2.7 The Dynamic zoom rectangle on screen

Fig. 2.8 The arrow against the right-hand edge of the dynamic rectangle

Fig. 2.9 The result of the dynamic zoom shown in Fig. 2.7

The Zoom tools

21

The Aerial View window Click View in the menu bar and in the drop-down menu which appears, click on Aerial View. The Aerial View window appears (Fig. 2.10).

Fig. 2.10 The Aerial View window

The window shows all of the drawing on screen and when a zoom is called, the area within a zoom is shown in the Aerial View window surrounded by a thick black line. Fig. 2.11 shows a zoomed window of the building drawing in Fig. 2.4 within the Aerial View window.

Fig. 2.11 A zoom window within the Aerial View window

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An Introduction to AutoCAD 2004: 2D and 3D Design

The Pan tool The Pan tool can be called either by entering p at the command line or by clicking on its tool icon in the Standards toolbar. When the tool is called the command line shows: Command:_pan Press ESC or ENTER to exit or right-click to display shortcut menu and an icon of a hand appears in the drawing area of the window. Dragging the mouse moves the drawing across the screen, the area covered being enclosed in a black rectangle in the Aerial window. The Pan tool is of particular use when constructing large drawings because it allows parts of the drawing which cannot be seen to be dragged into the drawing area. Fig. 2.12 shows the right-click menu which appears with a right-click and the Aerial View window when the building drawing given in Fig. 2.4 is panned to allow part of what is a large drawing to be seen in the drawing area.

Fig. 2.12 The Pan shortcut menu and the Aerial View window during panning

The wheel of a type of mouse Some types of mouse have a wheel, clearly seen in the example shown in Fig. 1.1 on page 1. The wheel can be used to zoom in, zoom out or pan a drawing when working with such a mouse in AutoCAD 2004. Rotating the wheel forward enlarges the drawing on screen – a Zoom In, while rotating the wheel backwards reduces the drawing in size – a Zoom Out. Pressing the wheel allows panning.

The Zoom tools

23

Revision tips 1. Make full use of zooms as and when necessary to achieve accuracy in constructions. 2. Toolbars can be brought to screen from the list appearing with a rightclick in any toolbar on screen. 3. The Zoom tool can be called from the Zoom toolbar, from icons in the Standard toolbar or by entering z at the command line. 4. The quickest method of calling zooms is to enter z at the command line. 5. Use the Aerial View window to see the whole drawing when zooms or pans are in action. 6. The Pan tool allows parts of large drawings to be clearly seen. 7. Use the wheel of some types of mouse for zooming in or out and for panning.

Exercises If you have saved the answers to the exercises from Chapter 1, open them and practise a variety of zooms and pans with the drawings on screen.

CHAPTER 3

Templates

Aims of this chapter This chapter is designed to introduce: 1. 2. 3. 4. 5. 6.

Templates. The template used for most of the drawings in this book. Other forms of template. A template such as used in industry. Saving and opening templates. Model Space (Mspace) and Paper Space (Pspace).

A template for use with this book Most of the drawings in this book have been drawn as if constructed on an A3 sheet of paper – i.e. of dimensions 420 mm by 297 mm. To make this possible the following settings have been made for a template for use when making these drawings: Limits – set to an origin of x,y ⫽ 0,0 and limit of x,y ⫽ 420,300. Thus when a drawing is printed full size (scale 1:1) each coordinate unit is equivalent to 1mm. Units – set with no figures after the decimal point. Grid – set to 10 units. Snap – set to 5 units. Text Style – set to Arial of height 6. Dimensions Style – set to an ISO style. Layers – 5 layers – 0, Hidden, Centre, Text and Dimensions with appropriate line styles. This template will be saved to the name A3_template. Templates have a file name extension *.dwt distinguishing them from a drawing file which has an extension *.dwg. Setting Limits

Fig. 3.1 The Format drop-down menu 24

Click on Format in the menu bar and from the drop-down menu which appears (Fig. 3.1), it will be seen that settings can be started from this menu. Either left-click on Drawing Limits in this menu or enter limits at the command line, which then shows:

Templates

25

Command:_limits Reset Model space limits: Specify lower left corner or [ON/OFF]: ⬍0.0000,0000⬎: right-click Specify upper right corner ⬍12.0000,9.0000⬎: 420,300 Command: To make sure the limits are applied: Command: enter z (Zoom) [prompts]: enter a (All) right-click Command: Setting Units

Note that before setting Units the status bar will show x,y coordinates to four decimal places – e.g. 45.0000,245.0000,0.0000. These will change to 45,245,0 when units have been set for this template. 1. Left-click Units . . . in the Format drop-down menu. The Drawing Units dialog (Fig. 3.2) appears. 2. In the Precision popup list click on 0, followed by a click on the OK button.

Fig. 3.2 The Units dialog

Setting Grid

At the command line: Command: enter grid right-click Specify grid spacing (X) or [ON/OFF/Snap/Aspect] ⬍1⬎: 10 Command:

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An Introduction to AutoCAD 2004: 2D and 3D Design

Setting Snap

At the command line: Command: enter snap right-click Specify snap spacing or [ON/OFF/Aspect/Rotate/Style/Type] ⬍1⬎: 5 Command: Setting Text Style

1. Click on Text Style . . . in the Format drop-down menu and the Text Style dialog appears (Fig. 3.3). 2. In the Font name popup list click Arial. 3. Click the New . . . button. The New Text Style dialog appears. Enter Arial in its Style name field (Fig. 3.4) and click its OK button. The name Arial appears in the Style name field.

Fig. 3.3 The Text Style dialog

Fig. 3.4 The New Text Style dialog

Templates

27

4. Enter 6 in the Height field of the Text Style dialog, followed by leftclicks on the Apply and Close buttons. 5. The text style is now set. Setting Dimension Style

1. Click on Dimension Style . . . in the Format drop-down menu. 2. In the Dimension Style Manager which appears, click the Modify . . . button (Fig. 3.5).

Fig. 3.5 The Dimension Style Manager dialog

3. The Modify Dimension Style dialog appears. Note there are six tabs in the upper part of the dialog. Click the Lines and Arrows tab, and in the changed dialog (Fig. 3.6) make entries as follows: Extend beyond dim line field – enter 3. Offset from origin field – enter 3. Arrow size field – enter 6. Center Mark for Circles popup list – select None. 4. Click the Text tab and in the Text dialog (Fig. 3.7) make entries as follows: Text Style – select Arial from the popup list. Text height – enter 6. Text Placement – select Above from the popup list. Horizontal – select Centered from the popup list. Offset from dim line field – enter 2. Text Alignment – click the ISO radio button. 5. Click the Primary Units tab and in the Primary Units dialog (Fig. 3.8) make changes as follows: Precision – in the popup list click on 0. Left-click the OK button.

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An Introduction to AutoCAD 2004: 2D and 3D Design

Fig. 3.6 The Lines and Arrows dialog

Fig. 3.7 The Text dialog

Templates

29

Fig. 3.8 The Primary Units dialog

6. In the Dimension Style manager dialog which now reappears, check that the dimension style as shown in the preview box is as wished. If satisfied: Click the New . . . button, and in the Create New Dimensions Style dialog make entries as shown in Fig. 3.9.

Fig. 3.9 The Create New Dimension Style dialog

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An Introduction to AutoCAD 2004: 2D and 3D Design

Left-click the Continue button. One of the dialogs of the Dimension Style Manager reappears. Left-click its OK button. The Dimension Style Manager reappears. Left-click on the name A3_template in the Styles list. Left-click the Set Current button. Left-click the Close button. Dimension style has now been set. Setting Layers

Drag the Layers toolbar away from its docked position under the Standard toolbar. Fig. 3.10 shows its parts. To set layers:

Fig. 3.10 The parts of the Layers toolbar

1. Left-click the Layer Properties Manager icon in the Layers toolbar. The Layer Properties Manager appears (Fig. 3.11). In the dialog, left-click the New . . . button four times. Four new layer names appear in the Name list as shown in Fig. 3.11. 2. Click the Layer1 name. Then double-click the name again. The name highlights. Enter Centre to replace Layer1. 3. Repeat for each of the other layers in turn to give the name Dimensions, Hidden and Text. Layer 0 – (default) cannot be changed. 4. Left-click on the word Continuous in the Centre layer line. The Select Linetype dialog appears. Left-click on its Load . . . button. The Load or Reload Linetypes dialog appears. In the Linetype list double-click the name CENTER2. This name replaces Continuous in the Centre layer line (Fig. 3.12). 5. Repeat item 4 to replace Continuous with HIDDEN2 for the linetype in the Hidden layer line. 6. Click on the black square against the layer Centre. The Select Color dialog appears (Fig. 3.13). In the dialog double-click the red square. The black square in the Centre layer line changes to a red square. 7. Repeat item 6 to make the colour for the Dimension layer Magenta, the Hidden layer Blue and the Text layer Green. 8. Left-click the OK button of the Layer Properties Manager.

Templates

Fig. 3.11 The Layer Properties Manager

Fig. 3.12 Setting linetypes in the layers

31

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An Introduction to AutoCAD 2004: 2D and 3D Design

Fig. 3.13 The Select Color dialog

To see the result of these additions to layers click the arrow to the right of the layers field in the Layers toolbar. The five layers are listed in the popup list with the layer names together with the linetypes and colours which have been allocated to the layers (Fig. 3.14).

Fig. 3.14 The layers popup list

Note the icons in this popup list. Clicks on these will turn a layer on or off, freeze a layer or lock a layer. When a layer is turned off details on that layer do not appear in a drawing. When a layer is locked objects on that layer cannot be modified – e.g. deleted, but details can be added to a locked layer. A click on any of these icons shows a tooltip describing the action of the icon.

Saving the template Templates must be saved with a filename extension *.dwt to distinguish them for drawing files with an extension *.dwg. To save the template: 1. Left-click File in the menu bar, and in the drop-down menu click Save As . . . . The Save Drawing As dialog appears (Fig. 3.15).

Templates

33

Fig. 3.15 Saving the template

2. In the Files of type popup list click AutoCAD Drawing Template (*.dwt). The AutoCAD 2004 Template directory name appears in the Save in field. 3. In the File name field enter A3_template. The name appears in the File list. 4. Click the dialog’s Save button and the file is saved. To reload the template click New . . . in the File drop-down menu. The contents of the Template directory appear in the Select Template dialog which appears on screen. The A3_template.dwt template can be opened from this dialog.

Another template Another template which may be considered worth saving is one similar to that shown in Fig. 3.16. Such a template includes a title block and borders. It may be of any coordinate limits in size – e.g. for an A2 sheet (597 mm by 420 mm) or an A1 sheet (820 mm by 597 mm). A large number of different templates are available from the AutoCAD 2004 template directory. These can be seen in the Preview box of the Select template dialog (Fig. 3.17). Many of these templates are in Paper Space, which provides a 2D drawing area. If one of the Paper Space templates from the Select template is opened, it will be seen that there are only x,y coordinates shown in the status bar.

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An Introduction to AutoCAD 2004: 2D and 3D Design 2

3

4

5

6

7

8

Fig. 3.16 Another type of template

B

AutoCAD 2004 1

2

Drawn by:

Dimensions in mm

Date drawn:

Tolerances ±0.05 unless shown

3

4

5

6

Title of drawing A

A

B

C

C

D

D

E

E

F

F

1

7

8

Fig. 3.17 An example of a template preview in the Select template dialog

Note on Model Space

The majority of drawings in this book are constructed in Model Space (Mspace). In AutoCAD 2004 drawings can be printed or plotted from either Model Space or Paper Space. More about this will be discussed later in this book. Switching from Model Space to Paper Space and vice versa can be effected by clicks on the Model or Layout tabs just below the drawing area.

Templates

35

Revision tips 1. The template for use with this book requires the following settings: Limits, Units, Grid, Snap, Text Style, Dimension Style and Layers. 2. This template has been saved to the name A3_template.dwt. 3. To open a template click New . . . in the File drop-down menu and select from the Select template dialog which appears. 4. Drawings in this book are usually constructed in Model Space. Paper Space will be used in later chapters.

CHAPTER 4

Accuracy when drawing

Aims of this chapter The contents of this chapter are designed to introduce the following when constructing drawings: 1. Further worked examples involving the Circle and Arc tools. 2. Further examples of constructing drawings to absolute coordinate entry. 3. Worked examples involving the use of constructions involving absolute coordinate entry. 4. Worked examples of using the tracking methods of determining accurate lengths when constructing drawings. 5. Using Object Snaps. 6. Using AutoSnap. 7. Using Polar tracking. 8. The importance of using Snap and Ortho. Note

All the worked examples in this chapter and the exercises at the end of the chapter should be worked on an A3_template brought to screen by selecting New . . . from the File drop-down menu.

The Circle and Arc tools A simple example of using these two tools was given in Chapter 1. The worked examples given below show further methods of using them. When the Circle tool is called the prompt appears: Command:_circle Specify center of circle or [3P/2P/Ttr]: If the response is 3P, a circle can be drawn through three points either picked on screen or entered as coordinate points. Similarly a circle can be drawn through two points. First example – Circle – the Ttr response

1. With the A3_template on screen, construct the two circles given in Fig. 4.1. 2. Call Circle again. The command line shows: 36

Accuracy when drawing 37 R50 R30

110,190

Fig. 4.1 First example – Circle – the Ttr response – the two circles

R30 245,190

135

Command:_circle Specify center of circle or [3P/2P/Ttr]: enter t (tan, tan., Radius) right-click Specify point on object for first tangent of circle: pick Specify point on object for second tangent of circle: pick Specify radius of circle: 55 Command: The result is shown in Fig. 4.2.

Fig. 4.2 First example – Circle – the Ttr response

When a tangent point is picked, a Deferred Tangent icon and tooltip is shown at the picked point (Fig. 4.3). Second example – the Arc tool prompts

The number of different methods of using the Arc tool for drawing arcs can be seen by selecting Arc from the Draw drop-down menu (Fig. 4.4). The Arc sub-menu shows the choices available. Fig. 4.5 gives some examples.

Constructions using absolute coordinates Deferred Tangent

Fig. 4.3 The Deferred Tangent icon

Some simple examples of constructions drawn by entering points on an outline as x,y coordinates have been given in Chapter 1. Two further examples are given here.

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An Introduction to AutoCAD 2004: 2D and 3D Design

First example (Fig. 4.6)

Call the line tool. The command line shows: Command:_line Specify first point: 50,250 Specify next point or [Undo]: 100,250 Specify next point or [Undo]: 100,250 Specify next point or [Undo]: 150,200 and continue in this way until the outline given in Fig. 4.6 is completed.

3 points

Fig. 4.4 The Arc sub-menu from the Draw drop-down menu

Start, Center, Length

Start, Center, End Continue

45°

Fig. 4.5 Second example – the Arc prompts

Start, End, Angle

50,250

Center, Start, End

100,250

250,200 150,200 280,270 150,140 250,140

Fig. 4.6 First example – absolute coordinates

50,90

100,90

Second example (Fig. 4.7)

Call the Line tool. The command line shows: Command:_line Specify first point: 100,200 Specify next point or [Undo]: 210,220 Continue until all straight lines have been drawn. Then:

Accuracy when drawing 39

Specify next point or [Close/Undo]: 110,120 Specify next point or [Close/Undo]: right-click Command: enter a (Arc) right-click Specify start point of arc or [Center]: 100,200 Specify second point of arc or [Center/End]: 50,170 Specify end point of arc: 100,200 Command: Continue in this way to construct the inner outline of Fig. 4.7.

100,220 100,200 50,170

210,220 200,200

70,170 100,140

Fig. 4.7 Second example – absolute coordinates

100,120

250,180 230,170

150,160

200,140 210,120

Constructions involving relative coordinate entry 90° 45°

135°

180°

0°

225°

315° 270°

Fig. 4.8 The counterclockwise direction of angles in AutoCAD 2004

In this method of constructing accurate drawings the prefix @ precedes each coordinate entry. Once a start point for a construction has been entered, coordinates are entered relative to the last point entered. Relative coordinate entries can be made in conjunction with absolute entries. The rules which govern relative coordinate entry methods are: ⫹ve X units are to the right horizontally. ⫺ve X units are to the left horizontally. ⫹ve Y units are vertically upwards. ⫺ve Y units are vertically downwards. The ⬍ symbol followed by a number indicates an angle in a counterclockwise (anticlockwise) direction in the full 360° range of angles (Fig. 4.8). First example – relative coordinate entry (Fig. 4.9)

Call the Line tool. The command line shows: Command:_line Specify first point: 50,250 Specify next point or [Undo]: @50,0 Specify next point or [Undo]: 150,200 Specify next point or [Close/Undo]: @100,0 Specify next point or [Close/Undo]: 280,170 Specify next point or [Close/Undo]: 250,140 Specify next point or [Close/Undo]: @⫺100,0 Specify next point or [Close/Undo]: 100,90 Specify next point or [Close/Undo]: @⫺50,0

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An Introduction to AutoCAD 2004: 2D and 3D Design

Specify next point or [Close/Undo]: c (Close) Command: and the outline given in Fig. 4.9 is drawn. @50,0

50,250

@100,0 150,200 280,170

c(Close) @–100,0

250,140

Fig. 4.9 First example – relative coordinate entry

@–50,0 100,90

Second example – relative coordinate entry (Fig. 4.10)

Call the Line tool. The command line shows: Command:_line Specify first point: 70,160 Specify next point or [Undo]: @60 ⬍ 45 Specify next point or [Undo]: @100,0 Specify next point or [Close/Undo]: @60 ⬍ 315 Specify next point or [Close/Undo]: @0,⫺90 Specify next point or [Close/Undo]: @⫺185,0 Specify next point or [Close/Undo]: c (Close) Command: enter c (Circle) right-click Command:_circle Specify center of circle or [3P/2P/Ttr]: .t (tan, tan., Radius). Specify point on object for first tangent of circle: pick Specify point on object for second tangent of circle: pick Specify radius of circle: 25 Command: Repeat for the other R25 circle followed by the two R15 circles. @100,0 R25

15

60