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In this chapter, we introduce AutoCAD and discuss the following:
Introduction and the basic commands.
The Create Objects commands.
The Edit/Modify Objects commands.
The View Objects commands.
The AutoCAD environment.
Interacting with AutoCAD.
Practicing the Create Objects commands.
Practicing the Edit/Modify Objects commands.
Selection methods—Window and Crossing.
Accuracy in drafting—Ortho.
Accuracy in drafting—OSNAPs.
By the end of the chapter, you will have learned the essential basics of creating, modifying, and viewing objects; the AutoCAD environment; and accuracy in the form of straight lines and precise alignment of geometric objects via OSNAP points.
Estimated time for completion of chapter: 3 hours.
1.1 INTRODUCTION AND BASIC COMMANDS
AutoCAD 2011 is a very complex program. If you are taking a class or reading this textbook, this is something you probably already know. The commands available to you, along with their submenus and various options, number in the thousands. So, how do you get a handle on them and begin using the software? Well, you have to realize two important facts.
First, you must understand that on a typical workday, 95% of your AutoCAD drafting time is spent using only 5% of the available commands, over and over again. So getting started is easy; you need to learn only a handful of key commands, and as you progress and build confidence, you can add depth to your knowledge by learning new ones.
Second, you must understand that even the most complex drawing is essentially made up of only a few basic fundamental objects that appear over and over again in various combinations on the screen. Once you learn how to create them and edit them, you will be able to draw surprisingly quickly. Understanding these facts is the key to learning the software. We are going to strip away the perceived complexities of AutoCAD and reduce it to its essential core. Let us go ahead now and develop the list of the basic commands.
For a moment, view AutoCAD as a fancy electronic hand-drafting board. In the old days of pencil, eraser, and T-square, what was the simplest thing that you could draft on a blank sheet of paper? That of course is a line. In your notes, write the following header, "Create Objects," and below it add "line."
So what other geometric object can we draw? Think of basic building blocks, those that cannot be broken down any further. A circle qualifies and so does an arc. Because it is so common and useful, throw in a rectangle as well (even though you should note that it is a compound object, made up of four lines). So, here is the final list of fundamental objects the way you should have them written down in your notes:
Create Objects * Line
As surprising as it may sound, these four objects, in large quantities, make up the vast majority of a typical design, so already you have the basic tools. We create these on the AutoCAD screen in a bit. For now, let us keep going and get the rest of the list down on paper.
So now that you have the objects, what can you do with them? You can erase them, which is probably the most obvious. You can also move them around your screen and, in a similar manner, copy them. The objects can rotate, and you can also scale them up or down in size. With lines, if they are too long, you can trim them and, if they are too short, extend them. Offset is a sort of precise copy and is one of the most useful commands in AutoCAD. Then there is mirror, used as the name implies to make a mirror-image copy of an object. Finally there is fillet, used to put a radius on two intersecting lines, among other things. We will learn a few more useful commands a bit later. But, for now, under the header "Edit/Modify Objects," list the commands just mentioned.
Edit/Modify Objects * Erase * Move * Copy * Rotate * Scale * Trim * Extend * Offset * Mirror * Fillet
Once again, as surprising as it may sound, this short list represents almost the entire set of basic Edit/Modify Objects commands that you will need once you begin to draft. Start memorizing them.
To finish up, let us add several View Objects commands. With AutoCAD, unlike paper hand-drafting, you do not always see your whole design in front of you. You may need to zoom in for a closeup or out to see the big picture. You may also need to pan around to view other parts of the drawing. With a wheeled mouse, so common on computers these days, it is very easy to do both, as we soon see. To this list we will add the regen command. It stands for regenerate, and it simply refreshes your screen, something you may find useful later. So here is the list for View Objects:
So, this is it for now, just 17 commands making up the basic set. Here is what you need to do:
1. As mentioned before, memorize them so you know what you have available.
2. Understand the basic idea, if not the details, behind each command. This should be easy to do, because (except for maybe offset and fillet) the commands are intuitive and not cryptic in any way; erase means erase, whether it is AutoCAD, a marker on a whiteboard, or a pencil line.
We are ready now to start AutoCAD, discuss how to interact with the program, and try them all out.
1.2 THE AUTOCAD ENVIRONMENT
It is assumed that your computer, whether at home, school, or training class, is loaded with AutoCAD 2011. It is also assumed that AutoCAD starts up just fine (via the AutoCAD icon or Start menu) and everything is configured right. If not, ask your instructor, as there are just too many things that can go wrong on a particular PC or laptop, and it is beyond the scope of this book to cover these situations. If all is well, start up AutoCAD, and you should see the screen depicted in Figure 1.1 (your particular screen may vary slightly, which we discuss soon).
This is your basic "out of the box" AutoCAD screen for the Initial Setup Workspace. From both the learning and teaching points of view, the new screen layout is a big improvement over older versions of AutoCAD, and Autodesk has done an admirable job in continuing to keep things clean and simple.
Part of that success is due to AutoCAD's major facelift, which began with Release 2009 a few years ago. If you caught a glimpse of earlier versions, you may have noticed toolbars present. They are still around, but what we have now, dominating the upper part of the screen, is called the Ribbon. It is a new way of interacting with AutoCAD, and we discuss it in detail soon. Other screen layouts or workspaces are available to you, including one with toolbars. They can be accessed through the menu seen in Figure 1.2, which is located at the bottom right (or top left) of the screen, depending on migrated settings. If you click on that menu, you will see the Workspace Switching Menu, shown in Figure 1.3. Here, you can also switch to AutoCAD Classic, which removes the Ribbon and loads the screen with toolbars and a palette, as seen in Figure 1.4.
So which workspace to use? Well, for now switch back to the Initial Setup Workspace with the Ribbon. We will shortly discuss how to interact with AutoCAD and give you some choices. Just before we do that though, let us go over the other features of the screen as seen in Figure 1.5. Here is a brief description of what is labeled there.
Drawing area. Takes up most of the screen and is usually colored black (white in this text). It is where you work and your design appears. If you wish to change it to to ease eye strain, you will need to right-click into Options ... then choose Display and Colors. We cover this in advanced chapters, so you should ask your instructor for assistance in the meantime, if necessary.
Command line. Right below the drawing area, usually colored white. It is where the commands may be entered and also where AutoCAD tells you what it needs to continue. You need to always keep an eye on what appears here, as this is one of the main ways that AutoCAD communicates with you.
UCS icon. A basic X-Y-Z (Z is not visible) grid symbol. Not important for now but will be later in advanced studies and 3D. It can be turned off, as will be shown later.
Model Space/Paper Space tabs. Not important for now, but will be in Chapter 10, "Advanced Output—Paper Space."
Toolbar. Toolbars contain icons that can be pressed to activate commands. They are an alternative to typing and the Ribbon, and most commands can be accessed this way. AutoCAD has dozens of them.
Crosshairs. The mouse cursor. It can be full-size and span the entire screen, or a small (flyspeck) size. You can change the size of the crosshairs if you wish, and full-screen is recommended in some cases.
Drawing and construction aids. These various settings assist you in drafting and modeling. We introduce them as necessary. An additional set of advanced drawing aids are on the far right of the screen.
Ribbon. A new way of interacting with AutoCAD's commands, to be discussed soon.
Tool palette. One of many in AutoCAD; they add more functionality, to be discussed later.
Cascading drop-down menus. Another way to access commands in AutoCAD.
1.3 INTERACTING WITH AUTOCAD
OK, so you have the basic commands in hand and ideally also a good idea of what you are looking at on the AutoCAD screen. We are ready to try out the basic commands and eventually draft something. So, how do we interact with AutoCAD and tell it what we want drawn? There are six overall and four primary ways. The four primary ways (Methods 1–4) follow, roughly in the order they appeared over the years. After them are the two outdated methods that are mentioned only in passing as a historical side note.
Method 1: Type in the commands on the command line (AutoCAD v1.0–current).
Method 2: Select the commands from the drop-down cascading menus (AutoCAD v1.0–current).
Method 3: Use toolbar icons to activate the commands (AutoCAD 12/13–current).
Method 4: Use the Ribbon tabs, icons, and menus (AutoCAD 2009–current).
Method 5: Use the screen side menu (outdated).
Method 6: Use a tablet (outdated).
Details of each method including the pros and cons follow. Most commands are presented in all four primary ways, and you can experiment with each method to determine what you prefer. Eventually you will settle on one particular way of interacting with AutoCAD or a hybrid of several.
Method 1: Type in the Commands on the Command Line
This was the original method of interacting with AutoCAD and, to this day, remains the most foolproof way to enter a command: good old-fashioned typing. AutoCAD is unique among leading CAD software in that it has retained this method while almost everyone else moved to graphic icons, toolbars, and Ribbons. If you hate typing, this will probably not be your preferred choice.
However, do not discount keyboard entry entirely; AutoCAD has kept it for a reason. When the commands are abbreviated to one or two letters (Line L, Arc A, etc.), input can be incredibly fast. Just watch a professional typist for proof of the speed with which one can enter data via a keyboard. Other advantages to typing are that you no longer have toolbars or a Ribbon cluttering up precious screen space (there is never enough of it) and you no longer have to take your eyes off the design to find an icon; instead, the command is actually at your fingertips. Finally, this method is the only way to enter a few of the commands (mostly in 3D). The disadvantage is of course that you have to type.
To use this method, simply type in the desired command (spelling counts) at the command line, as seen in Figure 1.6, and press Enter. The sequence initiates and you can proceed. A number of shortcuts are built into AutoCAD (try using just the first letter or two of a command), and we will learn how to make our own shortcuts in advanced chapters. This method is still preferred by many "legacy" users (a kind way to say they have been using AutoCAD forever).
Method 2: Select the Commands from the Drop-Down Cascading Menus
This method has also been around since the beginning. It presents a way to access virtually every AutoCAD command, and indeed many students start out by checking out every one of them as a crash course on what is available—a fun but not very effective way of learning AutoCAD. The cascading menus (so named because they drop out like a waterfall) may be hidden initially, but you can easily make them visible via the down arrow at the top left of the screen (next to the printer symbol). Select Show Menu Bar and they will appear. Go ahead and examine the cascading menus; these are similar in basic arrangement to other software and you should be able to navigate through them easily. We refer to them on occasion in the following format: Menu->Command. So, for the sequence shown in Figure 1.7, you would read Draw->Circle->3 Points.
Method 3: Use Toolbar Icons to Activate the Commands
This method has been around since AutoCAD switched from DOS to Windows in the mid-1990s and is a favorite of a whole generation of users; toolbars are a familiar sight with virtually any software these days. Toolbars contain sets of icons, organized by categories (example, Draw toolbar, Modify toolbar, etc.). You press the icon you want and a command is initiated. One disadvantage to toolbars, and the reason the Ribbon was developed, is that they take up a lot of space and, arguably, are not the most effective way of organizing commands on the screen. You can access toolbars by activating the AutoCAD Classic Workspace, or to have the Ribbon and toolbars, do the following while in the Initial Setup Workspace:
1. Type in toolbar and press Enter.
* AutoCAD says: Enter toolbar name or [ALL]:
2. Type in draw and press Enter.
* AutoCAD says: Enter an option [Show/Hide/Left/Right/Top/Bottom/Float] <Show >:
3. Type in s for Show and press Enter. The Draw toolbar appears, as seen in Figure 1.8.
To get more toolbars, you need not go through that procedure again. Simply right-click on the new toolbar and a menu appears, as seen in Figure 1.9. Then, just select the additional toolbars you want to see. Bring up Modify and Standard; those are the other two we will need in the beginning. Dock them all off to the side or next to the Ribbon on top.
Method 4: Use the Ribbon Tabs, Icons, and Menus
This is the most recently introduced method of interacting with AutoCAD and follows a new trend in software user interface design started by Microsoft and Office 2007 (seen in Figure 1.10 with Word®).
Notice how toolbars have been displaced by "tabbed" categories, where information is grouped together by a common theme.
So it goes with the new AutoCAD. The Ribbon was introduced with AutoCAD 2009 and it is here to stay. It is shown again in Figure 1.11.
Notice what we have here. A collection of tabs, indicating a subject category, is found at the top (Home, Insert, Annotate, etc.) and each tab reveals an extensive set of tools (Draw, Modify, Annotation, etc.). At the bottom of the Ribbon, additional options can be found by using the drop arrows. In this manner the toolbars have been rearranged in what is, in principle, a more logical and space saving manner. Additionally tool tips appear if you place your mouse over any particular tool for more than a second. Another second will yield an even more detailed tool tip. In Figure 1.12, you see the Home tab selected, followed by additional options via the drop arrow, and finally the mouse placed over the Polygon command. A few moments of waiting reveals the full tool tip for that command; pressing the icon activates the command.
Excerpted from Up and Running with AutoCAD 2011 by Elliot Gindis Copyright © 2011 by Elsevier Inc.. Excerpted by permission of Academic Press. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Part One Beginner to Intermediate
Chapter One AutoCAD Fundamentals 1
Chapter Two AutoCAD Fundamentals 2
Chapter Three Layers, Colors, Linetypes and Properties
Chapter Four DText, MText, Style and Editing
Chapter Five Bhatch
Chapter Six Dimensions
Chapter Seven Blocks and Wblocks
Chapter Eight Polar and Rectangular Arrays, Polygon and Circle/TTR
Chapter Nine Isometric
Chapter Ten Basic Printing and Output
Part II Intermediate to Advanced
Chapter Eleven Advanced Linework
Chapter Twelve Advanced Layers
Chapter Thirteen Advanced Dimensions
Chapter Fourteen Options, Shortcuts, CUI, Design Center & Exp. Tools
Chapter Fifteen Miscellaneous Topics
Chapter Sixteen Importing and Exporting Data
Chapter Seventeen External References
Chapter Eighteen Paper Space
Chapter Nineteen Attributes
Chapter Twenty Advanced Output and Pen Settings