Transcription

Tutorial Guide toAutoCAD 2012:2DFor Microsoft Windows SHAWNA off Development Corporation

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INTRODUCTION 59BASIC CONSTRUCTION TECHNIQUESIntroduction2You usually create drawings by combining and modifying severaldifferent basic shapes called primitives, such as lines, circles, and arcs,to create more complex shapes. This tutorial will help you learn howto use the AutoCAD software to draw some of the most commonbasic shapes. As you work through the tutorial, keep in mind that oneof the advantages of using CAD over drawing on paper is that you arecreating an accurate model of the drawing geometry. In Tutorial 3, youwill learn to list information from the drawing database. Informationextracted from the drawing is accurate only if you created the drawingaccurately in the first place.ObjectivesStarting3. Draw, using the Arcand Circle commands.Before you begin, launch the AutoCAD 2012 program.If you need assistance, refer to Getting Started 1 and 2 of this guide.4. Set and use runningObject snaps.Opening an Existing Drawing5. Change the display,using Zoom and Pan.This tutorial shows you how to add arcs and circles to the subdivisiondrawing provided with the datafiles that came with this guide. In Tutorial 3 you will finish the subdivision drawing so that the final drawingwill look like Figure 2.1.A SUBDIVISION LOCATED IN THE NE1/4 OF THE NE 1/4 OF SEC. 14,T.1S, R.5E, M.P.MA 15’ UTILITY EASEMENT ISRESERVED ALONG ALL EXTERIORLOT LINES.BRONWYNECSNROADGA2PONDETRRADY ROTAS110CIRCLE3456789Wannabe Heights EstatesFigure 2.1To open an existing drawing, you use the Application icon, Open selection or click the button that looks like an open folder from the QuickAccess toolbar.Click: Open buttonThe Select File dialog box appears on your screen. Use thecenter por tion, which shows the default directory and drive, to selectWhen you have completed this tutorial, youwill be able to1. Open existingdrawings.2. Work with new andexisting layers.6. Use Dynamic View.7. Draw ellipses.

60 Tutorial 2 BASIC CONSTRUCTION TECHNIQUESthe location where your datafiles have been stored. You should havealready created a directory called c:\datafile2012, and copied all thedatafiles for this book into it. If you have not done so, you may wantto review the Getting Started chapters. If the correct directory is notshowing in the Look In box, use the Up One Level icon or expand thechoices by clicking on the downward arrow for the Look In box. Usethe scroll bars if necessary to scroll down the list of directories and openthe appropriate one so the files appear in the dialog box as in Figure2.2. Scroll down the list of files until you see the file named subdivis.dwg. When you select a file, a preview of the file appears in the box tothe right. (Older files may not show a preview.)Tip: If you do not see a preview, pick Views from the dialog box’s menu bar and makesure that Preview is checked.Tip: Use the buttons at the leftof the dialog box to show theHistory (recently used files), MyDocuments folder contents, orFavorites you have added. Toadd a favorite, find the folderand then right-click the Favorites button. Pick Add CurrentFolder from the pop-up menuthat appears. To add a folderas a button, pick Tools, AddCurrent Folder to Places.Figure 2.2Menu choices at the top right of the Select File dialog box let you selectdifferent views to be displayed in the file list and other useful tools, suchas a Find selection to search for files.Click: Tools, FindType: subdivis (in the Named area)Click: Find Now button (from upper right of dialog box)The Find dialog box displays the location for the file named Subdivis.dwg, as shown in Figure 2.3. You can type in a portion of the name tomatch if you cannot remember the entire name or click the Date Modified tab if you want to search by date and time the file was created.

SAVING AS A NEW FILE 61Figure 2.3Double-click: Subdivis.dwg (from the list at the bottom)You return to the Select File dialog box.Click: OpenWhen you have opened the file, it appears on your screen, as shown inFigure 2.4. Note that it opens with its own defaults for Grid, Snap, andother features. These settings are saved in the drawing file. When youopen a drawing, its own settings are used.Figure 2.4Saving as a New FileThe Save As command allows you to save your drawing to a new filename and/or different drive or directory. You can select this commandfrom the Application icon or from the Quick Access toolbar.

62 Tutorial 2 BASIC CONSTRUCTION TECHNIQUESDon’t use the Save command, because that will save your changes intothe original datafile.Click: Save As buttonThe Save Drawing As dialog box appears.Figure 2.5On your own, select the drive and directory c:\work and specify the name for yourdrawing, subdivis.dwg, similar to Figure 2.5.The new file name is the same as the previous file name, but the directory is different. This creates a new copy of drawing subdivis.dwg savedin the directory c:\work.The original file c:\datafile2012\subdivis.dwg remains unchanged onyour drive. When you use the Save As command and specify a new filename, the software sets the newly saved file as current.Using LayersYou can organize drawing information on different layers. Think of alayer as a transparent drawing sheet that you place over the drawingand that you can remove at will. The coordinate system remains thesame from one layer to another, so graphical objects on separate layersremain aligned. You can create a virtually unlimited number of layers within the same drawing. The Layer command controls the colorand linetype associated with a given layer. Using layers allows you tooverlay a base drawing with several different levels of detail (such aswiring or plumbing schematics over the base plan for a building).By using layers, you can also control which portions of a drawing areplotted, or remove dimensions or text from a drawing to make it easierto add or change objects. You can also lock layers, making them inaccessible but still visible on the screen. You can’t change anything on alocked layer until you unlock it.Current LayerThe current layer is the layer you are working on. Any new objects youdraw are added to the current layer. The default current layer is Layer 0.

CONTROLLING LAYERS 63If you do not create and use other layers, your drawing will be createdon Layer 0. You used this layer when drawing the plot plan in Tutorial1. Layer 0 is a special layer provided in the AutoCAD program. Youcannot rename it or delete it from the list of layers. Layer 0 has specialproperties when used with the Block and Insert commands.Layer POINTS is the current layer in subdivis.dwg. There can be onlyone current layer at a time. The name of the current layer appears onthe Layer toolbar.Controlling LayersThe Layer Control feature on the Layers panel on the Home tab of theribbon is an easy way to control the visibility of existing layers in yourdrawing. You will learn more about creating and using layers in thistutorial. For now, you will use layers that have already been created foryou.Click: on layer name POINTS from the Layers panelThe list of available layers pulls down, as shown in Figure 2.6. Noticethe special layer 0 displayed near the top of the list.Figure 2.6Click: on the layer name CENTERLINE from the Layer Control listIt becomes the current layer shown on the toolbar. Any new objects willbe created on this layer until you select a different current layer. TheLayer Control now should look like Figure 2.7, showing the layer nameCENTERLINE.Figure 2.7Use the Line command you learned in Tutorial 1 to draw a line off to the side ofthe subdivision drawing.Note that it is green and has a centerline linetype (long dash, shortdash, long dash). The line you drew is on Layer CENTERLINE.Erase or Undo the line on your own.

64 Tutorial 2 BASIC CONSTRUCTION TECHNIQUESControlling ColorsEach layer has a color associated with it. Using different colors for different layers helps you visually distinguish different information in thedrawing. An object’s color also may control which pens are used duringplotting.There are two different ways of selecting the color for objects onyour screen. The best way is usually to set the layer color and drawthe objects on the appropriate layer. This method keeps your drawingorganized. The other method is to use the Color Control feature on theProperties panel. To select the Color Control pull-down feature,Click: ByLayer, from the Properties panel to pull down the ColorControlTip: If your panelsare minimized, youmay need to click toexpand the options.Click to expandcolor choicesFigure 2.8Note that the standard colors (yellow, red, green, blue, etc.) are shown.You can also choose Select Color to view the full color palette.Click: Select ColorThe Select Color dialog box shown in Figure 2.9 appears on yourscreen, giving you a full range of colors from which to choose.Tip: On a black background,color 7 used for layer 0 appearsas white; on a white background it appears black.Figure 2.9The three tabs of the Select Color dialog box allow you to choose

LAYER VISIBILITY 65among different methods to determine the color for your drawingentities. The True Color tab allows you to set color to either RGB, whichstands for Red, Green, Blue, the primary colors of light, or HSL, whichstands for the Hue, Saturation, and Luminance of the color. The ColorBooks tab lets you select from among different standard ink manufacturer’s predefined colors so that you can match print colors very closelyto the colors you choose on your screen. In this text you will use IndexColor (AutoCAD Color Index) as the method for selecting color.Make sure the Index Color tab is selected.The default option for the Color (and also for the Linetype) commandis BYLAYER. It’s the best selection because, when you draw a line,the color and linetype will be those of the current layer. Otherwise, thecolor in your drawing can become very confusing. You will click Cancelto exit the Select Color dialog box without making any changes. Thecolors for your new objects will continue to be determined by the layeron which they are created. Layers can have associated linetypes, as wellas colors, as Layer CENTERLINE does.Click: CancelLayer VisibilityOne of the advantages of using layers in the drawing is that you canchoose not to display selected layers. That way, if you want to createprojection lines or even notes about the drawing, you can draw themon a layer that you will later turn off, so that it isn’t displayed or plotted. Or you may want to create a complex drawing with many layers,such as a building plan that contains the electrical plan on one layerand the mechanical plan on another, along with separate layers for thewalls, windows, and so on. You can store all the information in a singledrawing, and then plot different combinations of layers to create theelectrical layout, first-floor plan, and any other combination you want.Next, use the Layer Control to lock Layer POINTS, freeze Layer TEXT,and turn off Layer EXISTING ROAD.Click: on Layer CENTERLINE to show the list of layersThe list of layers pulls down. Refer to Figure 2.10 as you make thefollowing selections.Click: the On/Off icon, which looks like a lightbulb, to the left ofLayer EXISTING ROADClick: any blank area of the screen away from the Layer list toreturn to the drawingNote that the blue roadway lines have been turned off so that theyno longer appear. Invisible (off) layers are not printed or plotted, butobjects on these layers are still part of the drawing.Figure 2.10Layer Control

66 Tutorial 2 BASIC CONSTRUCTION TECHNIQUESFreezing LayersFreezing a layer is similar to turning it off. You use the freeze option notonly to make the layer disappear from the display, but also to cause it tobe skipped when the drawing is regenerated. This feature can noticeablyimprove the speed with which the software regenerates a large drawing.You should not freeze the current layer because that would create asituation where you would be drawing objects that you couldn’t see onthe screen. The icon for freezing and thawing layers looks like a snowflake when frozen and a shining sun when thawed.Click: to expand the Layer Control listClick: the Freeze/Thaw icon to the left of Layer TEXTClick: any blank area in the graphics window to return to thedrawingLayer TEXT is still on, but it is frozen and therefore invisible. A layercan both be turned off and frozen; the effect is similar. You shouldeither freeze a layer or turn it off, but there is no point in doing both.Your screen should now be similar to Figure 2.11.Figure 2.11Locking LayersYou can see a locked layer on the screen, and you can add new objectsto it. However, you can’t make changes to the new or old objects onthat layer. This is useful when you need the layer for reference but donot want to change it. For example, you might want to move severalitems so that they line up with an object on the locked layer but preventanything on the locked layer from moving. You will lock layer POINTSso that you cannot accidentally change the points already on the layer.Click: the Lock/Unlock icon to the left of Layer POINTS

MAKING OBJECT’S LAYER CURRENT 67Now, Layer CENTERLINE is the current layer. (If for some reason it isnot the current layer, set it current at this time.) Layer TEXT is frozenand does not appear. Layer EXISTING ROAD is turned off and doesnot appear. Layer POINTS is locked so that you can see and add to it,but not change it.On your own, try erasing one of the circled points in the drawing.A message appears, stating that the object is on a locked layer. Theobject won’t be erased.Making Object’s Layer CurrentThe Make Object’s Layer Current button is located above the LayerControl pull-down (Figure 2.11). This command lets you select anobject and then click on the icon to make that