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Wiley AutoCAD: Secrets Every User Should Know

1. i O H EL ea SS a At 585 78 TAL NOS LOCK NUT 375 X 1875 KEYSEAT belongs They could drag the value right or left so it could be seen in one of the viewports See Figure 1 1 The entire part is shown at the bottom with the conventional break cre ated with two floating viewports above Draw Existing Features as Built This tip probably seems obvious but I ve been asked more than once what I recommend when designing for renovations or additions to existing structures The question is usually in this form I have the original drawings of the building Should I use them to create an AutoCAD drawing of the existing structure or should I create the AutoCAD geometry as built Clearly creating geometry as built rather than as designed permits you to solve problems in the software instead of in the field because few actual structures didn t change in some way from the original plans You can use the original plans to create a base draw ing and then check key locations and dimensions for changes This is one of the great ben efits of using such a precise design system You can reduce what some builders call on site engineering by drawing everything as accurately as you possibly can That way the results are much more likely to match the plans Who knows Someday as built and as designed may become the same thing Draw Mechanical Parts at MMC My advice to dr
2. for the full story but for now follow these steps in sequence when you create a new drawing file 1 Create your geometry full size in Model Space but don t add dimensions text or hatches 2 Set up a layout with all views at the proper plot scale 3 Add dimensions text hatches and schematic symbols to your drawing from a layout with a properly scaled viewport Use the command CHSPACE an Express Tool before AutoCAD 2007 to move objects between Paper Space and Model Space If you put something in the wrong spot it s easy to change it and have it scaled automatically so it plots as you intend Draw Perfectly Somebody Will Assume You Did I ve heard some horror stories about AutoCAD drawings that were done using the Etch A Sketch method and then reused later by someone who assumed they were done accu rately Most of these stories involve hapless users stuck with their predecessors drawings but in some cases users run into trouble by relying on their own inaccurate drawings In one case which involved a lawsuit and a lot of money a bid was made on a structural design based on the assurance that accurate AutoCAD drawings of the existing structure would be provided by the client Unfortunately those drawings were facilities drawings done to show egress and general locations and were unusable for the intended purpose How does this happen Because most AutoCAD drawings look accurate even if they aren t we fo
3. In my experience most users don t understand rotated dimensions All linear dimensions are either aligned or rotated but most are rotated Vertical dimensions are rotated to 90 DIMALIGN horizontal dimensions to 0 Because those angles are built in users often overlook the possibility of rotating dimensions to other angles and frequently attempt to use an aligned dimension where a rotated one is needed Figure 1 19 shows the problem with trying to use DIMALIGN To place a rotated linear dimension between two points at any angle use DIMLINEAR and select the DIMLINEAR with Rotate option Rotated option You can specify a rotation angle directly or by picking any two points that are at the desired angle of rotation FEATURE REVIEW ALL RELEASES 31 ORDINATE Ordinate dimensions are used to set dimensions as coordinates in the X and Y axes Ordi nate dimensioning is used most often in mechanical drawing but it s increasingly being used in architectural and other fields as well When I draw a structure that I ll be building myself I always dimension it with ordinate dimensions rather than with continuous dimensions which is the traditional method That way I can hook a tape to one end of a sole or top plate and mark all locations of openings from a fixed point Although there s a DIMORD command the quickest way to place ordinate dimensions is with QDIM Select the points you wish to dimension
4. and then select a new datumPoint for 0 0 Now you can choose the Ordinate option select your objects and place all ordi nate dimensions with one pick If you have objects with different base points use the datumPoint option again To facilitate the use of ordinate dimensions you can place points using the POINT command at every location you wish to use as an origin Using either the FILTER or QSELECT command you can now select only points Doing so prevents you from inadvertently selecting too many objects If you don t use QDIM you must first establish a new base point by setting a UCS with its origin at the 0 0 location on the part you re dimensioning Use the UCS command select the Origin option and then select the 0 0 point on the part If UCSICON is ON and set to ORigin the icon representing the UCS moves to the new origin point AutoCAD automatically places the correct distance in the X or Y direction depending on which direction you move from the dimension origin point you pick These dimension values are associated with defpoints not the objects themselves if DIMASSOC is 1 or 2 This association is maintained for the UCS that was current when the dimension was placed Stretching the defpoints of the dimensions results in the values being updated correctly even if a new UCS has been set since the dimension was created Dimension Variables AutoCAD 2007 includes 79 dimension variables The easiest way to change them is usi
5. with DIMANGULAR and get the angle between the segments defined by the points PROPERTIES and LIST Both these commands give you information that varies by entity selected including the arc length of an arc PROPERTIES can be used to change the properties of multiple objects as well as individual objects For example you can change the height of all text in the drawing without changing the locations One piece of information that you can get from the LIST command that you can t get from the Properties palette is an object s handle This may seem meaningless to you now but the handle can be useful because it s the unique identifier of an object and never changes Figure 1 15 2x Using regions DE Pics Points to calculate a sae S complex area Pi S lsbmd detection _ C ha r Boundary retention CIST FF Fess tearing we apse Dbiect ye Petre gt ran Regon O Q f Banday ime eS O Pd Cunent viswpot T al New o cmd Heb 24 CHAPTER 1 AUTOCAD PRODUCTIVITY Figure 1 16 WBLOCK options for saving a DWG file TIME TIME gives you the total time during which a drawing has been open for editing You can also use it as a running timer by selecting the Reset option before beginning something new Use this timer as you try to develop more drawing speed Pick one object and draw it several times using different strategies The TIME command can tell you if you re getting any faster ve also us
6. 25 or so to see linetypes properly in a layout you ve probably started your drawing in imperial units but are drawing objects measured in millimeters If you need a small setting say 04 then it s likely that you have the opposite problem You started a drawing in metric units but are drawing in inches See the earlier section Control Imperial vs Metric Units Layers A number of things about layers can give you problems Here are a few of them Locking allows you to lock a layer so that it s visible but not changeable You can still use osnaps on the visible entities Most users would benefit from using layer locking more often to avoid inadvertent changes to their drawings People sometimes confuse layer locking with viewport locking in a layout They do different things and aren t related Locking a layer doesn t affect the display of objects in any way Locking a viewport doesn t prevent you from changing objects in that viewport Layer filters and freezing layers by viewport VPLAYER are useful advanced com mands in the Layer Properties Manager dialog box You can change layer names in the Layer Properties Manager dialog box but the RENAME command is faster when you re changing names of layers from a bound XRef because you can use wildcards Layer 0 is the only layer you can t rename Plot No Plot settings can be made for layers so there s no longer a need to use the Defpoints layer for that purpose
7. DIMSCALE of 0 before dimensioning allows you to add dimensions in viewports with different zoom magnifications and have them all come out the same size Select Scale Dimensions To Layout in the Dimension Style Man ager dialog box on the Fit tab See Chapter 6 for detailed information on plotting Many offices still use the once standard practice of setting DIMSCALE to a value that reflects the reciprocal of the plot scale This is a legacy of the old days of AutoCAD when such prac tice was required If you choose to change this practice you should do so in the context of a complete overhaul of office standards Such an overhaul should of course include all affected parties Settings Commands This section discusses some of the system variables the setvars in AutoCAD but cer tainly not all of them What follows are the settings that people sometimes overlook or that I have specific recommendations about System variables control the appearance or behavior of AutoCAD You normally set these by making a selection in an appropriate dialog box but they can also be set from the command line Old time users probably do this a lot by typing the variable name quickly If I want to change my linear unit precision to check something I type LUPREC and then type 8 When I have the information I want I undo that action or type LUPREC again FEATURE REVIEW ALL RELEASES 33 Not everyone can touch type however I appreciate being able to This ma
8. Don t make Defpoints the active layer because any objects you add to it won t plot I ve seen two cases of odd behavior with objects placed on the Defpoints layer One user was unable to select a viewport even though it was visible and another placed points on that layer but couldn t change their appearance In the viewport case freezing layer 0 created the problem And points can t be displayed as anything other than a single pixel on the Def points layer The only reason to place objects on the Defpoints layer is the security of know ing that no one will accidentally plot them FEATURE REVIEW ALL RELEASES 35 Lineweight should be set to BYLAYER A default value of 20mm and an object line value of 40mm usually give a good lineweight distinction A button on the Layers toolbar makes the layer of a selected object current xe A button on the Layers toolbar restores the previous layer state Display Commands Tm sure you frequently use the All Extents and Window options of the ZOOM com mand but have you ever saved the results with a name so you can return to it quickly If you have to connect two small features that are widely separated have you ever used VPORTS to place two views in the Model Space tab and drawn from one to the other Read on VIEW It surprises me how few people use this feature It allows you to save a specific view on the screen or as defined by a window so that you can immediately cal
9. anything Standard Be Cautious When Using REFEDIT REFEDIT is used to edit block definitions or external reference drawings it replaces the originals if you tell it to If you click Save Reference Edits you d better mean it You can protect a drawing that will be used as an external reference XRef from being edited with REFEDIT by setting the variable XEDIT to 0 before saving the intended XRef Before AutoCAD 2006 double clicking a BLOCK insertion opened REFEDIT Users who didn t understand what REFEDIT was would close the resulting toolbar and keep working Unfortunately they were still reference editing without knowing it and eventually they got the not in the working set error If you get this error type REFCLOSE at the command line Beware When Moving or Renaming Files Don t change filenames or locations for hyperlinks XRefs XRef images menu files icon BMP files or other support files unless you know how to redefine the path used to locate them Otherwise you ll get blank rectangles for images and a line of text for XRefs your menus won t load many commands won t work or you ll see clouds or questions marks on your custom toolbars Using the Relative Path option can help for images and XRefs THE PROBLEM WITH STANDARD Every AutoCAD drawing uses Standard as the default name for styles At some point you may insert your drawing into another host drawing If you never bothered to rename the style you use you ll have
10. behind that are on top of each other I ve seen this lead to subtle but often important errors The often related problem of lines on top of lines may seem like no big deal because everything plots fine but if you have a short line segment on top of a longer one it s possible to snap to the wrong endpoint or midpoint without noticing it and create inaccurate geome try The OVERKILL Express Tool can help fix this problem MPEDIT was once an Express Tool It allows you to set a fuzz factor for combining lines arcs or plines into a single object To use it run MPEDIT and then select all the objects you want to join You re prompted for a fuzz factor Enter a number that is greater than your likely error and MPEDIT cleans up the mess I hope you re working on some one else s mess because you should be able to avoid sloppy drawing if you use the accu racy tools available in AutoCAD There are also some alternatives to PEDIT for finding areas even if your closed geome try has overlapping lines Using the BOUNDARY command you can select a point and have a closed pline or a region created automatically This works great for interior spaces but you can use this command even in situations that are less obvious For example when you have overlapping construction lines and want to create a clean set of double lines a floor plan for example use the technique shown in Figure 1 8 Enclose the entire group of lines with a circle and
11. can quickly create a slot by selecting two parallel lines when prompted by the FILLET command DIVIDE and MEASURE These commands behave similarly The difference is that DIVIDE results in an entity divided into a specified number of segments all the same length MEASURE divides the entity into segments of a given length with one shorter segment usually at the end Enti ties aren t actually segmented instead a point is placed at each division The appearance of all the points in a drawing except those on the Defpoints layer is con trolled by the variable PDMODE You can set this variable using the Point Style dialog box It s also possible with either DIVIDE or MEASURE to have a block inserted at each division instead of a point which is a useful and often overlooked feature You can quickly approximate a complex linetype for example by placing any block along a line pline or spline object This works well for placing arrows on an egress map see Figure 1 17 Using MEASURE to place blocks FEATURE REVIEW ALL RELEASES 27 EXPLODE You can use EXPLODE with the following entities blocks hatches mlines plines solid objects and blocks of text created with the MTEXT command Any blocks can be exploded except those placed using the MINSERT command For that reason MINSERT should not be used unless you want a block that can t be exploded When you use EXPLODE be care ful not to select more
12. current layer Freeze all layers that don t start with the characters FL7 Your code should look like this Layer T S FL1 F FL1 The is a wildcard meaning all The tilde is a wildcard meaning all except If you find it necessary to apply a color or linetype directly to an object rather than to ByLayer recommend doing so with the Properties palette after the object is created If you select the color in the Properties toolbar you may forget to set it back to ByLayer and continue draw ing You should close the Properties toolbar to avoid using it See Figure 1 2 Use the Drafting Tools Learn to use direct distance entry osnaps object tracking temporary tracking and polar tracking They re great tools that can dramatically speed up your work once you under stand how they work together Check out the newer osnaps like M2P Temporary Track Point Parallel and Extension However don t overdo the running osnaps Open the Drafting Settings dialog box and uncheck as many as possible in the Object Snap tab If you re drawing lines at unusual angles and you want to be able to continue with lines that are perpendicular from the last line segment you drew set PER as a running osnap and hover over the end you just selected Figure 1 2 Set properties to ByLayer E ByLayer hd ByLayer Le Byler X ByColor 7 AUTOCAD BEST PRACTICES Plot from Layouts in Paper Space Read Chapter 6 Plotting
13. on the object Draw the whole pattern once and then array the result rather than arraying each of the components of the pattern separately Be careful It s easy to select an extra entity when you use the Polar option of ARRAY The result looks fine but you have entities on top of each other The image in Figure 1 7 illustrates an efficient technique for using polar arrays by identifying and creating the repeatable pattern before arraying anything The repeatable pattern is shown on the left and the result of doing a single array of that pattern is on the right The alternative involves multiple construction lines and six times more editing for each feature PEDIT After using ARRAY to create geometry from lines and arcs you can determine whether the result is perfect using the PEDIT command If you use PEDIT to join lines into a closed object they can only be joined if they connect perfectly at all intersections Your geometry is perfect if the first option of PEDIT Close changes to Open after you ve joined all your lines If the geometry isn t perfect and sometimes that can t be helped you can still join the segments into a single object using the MPEDIT command Q FEATURE REVIEW ALL RELEASES 17 REDUCE CONSTRUCTION LINES Try to use as few construction lines as possible when creating geometry The more lines you use to locate points or edges the more chances that you may confuse one or more for actual lines or leave lines
14. 0 It also involves using the often overlooked Relative option of AutoCAD s polar tracking feature To set polar tracking to Relative right click the POLAR button at the bottom of the screen and select Settings Select the Relative To Last Segment radio button in the Polar Tracking tab of the Drafting Settings dialog box Select the Track Using All Polar Angle Settings option as well as shown in Figure 1 10 FEATURE REVIEW ALL RELEASES 19 Note that in this case Increment Angle is set to one 1 This is a small angle and it isn t easy to work with but it can be used If the angles you re using are based on larger increments use them It s much easier to use an angle increment of 5 15 or 45 but any increment can be typed into the window including values so small they are completely unusable as angles That s one of the things love about AutoCAD It doesn t restrict what you can do by overpro tecting you from the results of commands In Figure 1 11 supplemental angles are determined from the interior angles and used ge 4 61 es to calculate the resulting relative angle of the next line segment As you draw use the read Fa f out from polar tracking to determine the relative angle for the next segment Sometimes it will be reported to you as 299 instead of 61 for example because it s increasing in the clockwise direction rather than the default counterclockwise direction Fig
15. Auto CAD 2006 displayed the text in place which meant he had to tilt his head to the side to read it He was about to rotate the title block for editing when he decided to call me knew the MTEXTED variable would allow him to change the MTEXT editor to the previ ous version so he could use horizontal text but didn t remember the correct setting for doing so As he was asking the question used the Help system to look up the MTEXTED variable and then told him to set it to OldEditor He sighed and asked How can you know everything about AutoCAD When admitted that in this case my secret was the Help sys tem think heard him slap his forehead No one can know everything about AutoCAD but if you want to be the indispensable AutoCAD go to user in your office become familiar with Help Whether you reveal your secret source is up to you Use Layers with Logical and Consistent Names Using layers with logical names allows you to separate different kinds of geometry and different functions Don t be one of those people who produce nightmare drawings by placing all or most entities on a single layer Layers give you control over a drawing that s essential to efficient management If your layer names are logical it s easy to manage multiple layers That logic should be embedded in an office standard and reflected in the use of stan dard drawing templates and a DWS standards file There have been many attempts to standard
16. CHAPTER 1 AutoCAD Productivity Co NS ide rung the complexity of AutoCAD it s not surprising that many people who use it miss something important along the way Many users had little training on the software before being expected to start producing useful work and these users in turn have trained others based on what they figured out on their own Even the most experi enced AutoCAD users have likely forgotten some useful things they once knew This chapter is the result of the many questions I ve been asked by AutoCAD users over the years while teaching training consulting and responding to e mails and phone calls Here I ll offer advice on using AutoCAD with an emphasis on features and techniques that are often overlooked or forgotten by users I ll include general design advice that applies to the use of any CAD system providing my recommendations for universal stan dard practice in using AutoCAD reviewing techniques and commands that apply to all releases of AutoCAD This chapter isn t meant to be a comprehensive review of AutoCAD many excellent books already provide that nor is it a replacement for learning how to use the software What I ve selected here are items that people often overlook Design Standards AutoCAD Best Practices Feature Review All Releases 2 CHAPTER 1 AUTOCAD PRODUCTIVITY Design Standards CAD software is used in so many fields of design that it would be impossible to develop exte
17. LOCK1 and loner dees so on type STP123 0 in the Old Name field and in the Rename To awd field as shown in Figure 1 21 la Dimension syes PARTIALOPEN You can elect to open part of a drawing to reduce regeneration time on large drawings Highlight a file and then select the Open button in the lower right corner of the Select File dialog box that s used to open an existing drawing The Partial Open dialog box that s displayed can be Confirm each item to be purged used to select only those layers or views with which you want to work R Once you ve used PARTIALOPEN to open part of a drawing you can use the PARTIALLOAD command found on the File pull down menu eue Cose J _Hep J to select different layers There is a design flaw in PARTIALLOAD You must reselect all layers each time you do a partial load The lay 21x in os Named Objects Items ers you first selected aren t remembered This issue wasn t addressed 5 Dimension styles in AutoCAD 2007 but I m hoping it will be fixed someday Layers Express Tools Uese The Express Tools which started as Bonus Tools have always been popular with AutoCAD users Many users haven t found them or Od Name erias haven t taken the time to understand them or these tools aren t Bename To ne loaded on their workstation Some afternoon when you have a lit Cancel Help tle time go to the Express pull down menu and select Help Now you
18. a conflict in the host drawing between its dimension style and yours Only one of the two styles named Standard can win this fight Will it be your drawing or the draw ing into which it s inserted Hint Your drawing will lose this fight and all your dimensions will look awful if you explode the resulting block AUTOCAD BEST PRACTICES 11 Control Imperial vs Metric Settings Starting from scratch with either an imperial acad dwt or metric acadiso dwt template controls the files used for linetypes and hatch patterns ACAD 1in and ACAD pat are used for imperial and ACADISO 1in and ACADISO pat are used for metric You can change this using the MEASUREMENT variable The imperial setting is 0 the metric setting is 1 Changing this doesn t change the limits or the default dimstyle after the fact When youre plotting a metric drawing change the drawing area to Metric in the Plot dialog box if you are using a release prior to AutoCAD 2005 AutoCAD 2005 made a change in the plotting process When you plot a drawing starting with the metric template or when you ve changed the setting for Measurement to 1 and you select a paper size measured in inches the plot scale is automatically set to 1 25 4 If you get odd results when plotting check this value Learn to Use QSELECT QSELECT is very useful when you re trying to fix a problem drawing I once received a DXF file from the engineer of our city hall He had generated a large number
19. an do this through AutoCAD DesignCenter or by inserting a drawing that contains the dimension style but these Express Tools make it a little easier DIMREASSOC This is a nice tool It permits you to individually or globally update dimen sions that have been overridden by the operator In other words the value in the dimension and the actual size of the object don t match My favorite application of this command is to find any dimensions that were overridden I have overridden a dimension purposely on rare occasions when I had an imminent deadline and had to plot something out immedi ately With DIMREASSOC I can find those places and go back and fix the geometry FEATURE REVIEW ALL RELEASES 39 You can also change the overwritten dimensions automatically which may cause even more problems if you don t notice what got updated The problem is that the value is probably overridden because the geometry is wrong SYSVDLG The System Variables editor is a wonderful tool It gives you a concise list of each system variable tells you where its value is stored and describes what it does The best thing is that you can save the settings to an SVF file and restore them if you ever have to If you do any training using computers that aren t your own take this file with you it will reduce the number of surprises you may encounter OVERKILL This command gets rid of overlapping lines line segments that connect in what appears to be a singl
20. aw mechanical parts at Maximum Material Condition MMC may be less obvious than my as built advice because mechanical parts always have a specified DESIGN STANDARDS 3 Figure 1 1 Conventional break for long part 4 CHAPTER 1 AUTOCAD PRODUCTIVITY tolerance at least they re supposed to The question is where in that range should you create your accurate to 15 decimal places geometry when using a CAD system You know it s impossible to make anything an exact size If you think you can you re not using a precise enough measuring tool There are several possibilities Some people draw objects in the middle of their size tol erance range Others use what they consider the design size or nominal size the base size given before the plus minus sign After all isn t that the ideal size Well it may be the ideal size but neither of these approaches is good practice whether you re creating a 2D drawing or a 3D model The fact is a mechanical part has no ideal size If a part is designed properly and given a functional tolerance as required it will work fine as long as its dimensions fall within that tolerance No size in that tolerance will make the part per form better than any other size As a machinist you may aim for the middle of a range but not because that makes a better part You do that to reduce the chances of making the part too small or too large and having to throw it out Draw all parts and create all soli
21. can read about each tool and get inspired Figure 1 21 Using wildcards when renaming If you don t have the Express Tools loaded on your workstation try typing the command objects EXPRESSTOOLS at the command line They may show up If they don t the tools may not have been loaded by whoever installed AutoCAD This is likely to be the case if you use Architec tural Desktop ADT prior to Release 2007 because loading Express Tools isn t listed as an option during the install You have to have the install CD know where on the CD the Express Tools are stored a folder named Express and then load them manually This is because CHSPACE will corrupt some pre Release 2007 ADT objects 38 CHAPTER 1 AUTOCAD PRODUCTIVITY CHSPACE This command is indispensable and it has finally evolved from an Express Tool into a native command in AutoCAD 2007 It lets you change objects between Paper Space and Model Space while retaining their relative scales This makes it possible to place text or dimensions wherever it s convenient while working and then move them to their perma nent home later If you ever decide you placed something in the wrong space you need this command LAYWALK This tool allows you to walk though the objects on various layers to give you a visual clue as to what you ve placed where It s valuable when you re dealing with someone else s disaster drawing The objects on each layer are isolated temporarily while you cycle t
22. d models at MMC unless it s one of those rare features that are controlled at Least Material Condition LMC in a tolerance frame Features with outside dimensions like a shaft or a pin should be drawn at their largest acceptable size Features that have inside dimensions like a hole or a slot should be drawn at their small est possible size In both cases the result is a part with the maximum amount of material in it That s usually when parts are least likely to go together this approach allows you to draw parts in the situation where they re most likely to fail and to check for interferences more readily It s also easier to be consistent this way because the rules for Geometric Dimensioning and Tolerancing assume MMC for many of the specific situations where the rules apply I recommend this approach for both 2D and 3D modeling including when youre using Mechanical Desktop Inventor or any other CAD package Use Logical Increments When designing something you can use any size increment you wish If you choose incre ments that are easy to work with or that result in less waste during fabrication you save both time and materials During the early design stages you can set a SNAP to that incre ment in AutoCAD with a GRID set to twice the increment Doing so can speed up the ini tial layout For architectural design I recommend using the largest increment possible such as whole inches one foot two feet or four feet Doing s
23. e all the entities erased as a single selection set the last time the ERASE command was used It doesn t have to be issued immediately after the entities are erased More often than I should I erase objects that are in the way of a deli cate editing operation and then I use OOPS to get them back after m done editing I don t recommend this approach but I do it OOPS restores objects even if their layer is currently frozen or turned off 28 CHAPTER 1 AUTOCAD PRODUCTIVITY Figure 1 18 Using the Reference option of the SCALE command ROTATE The remarkably useful and often overlooked option of ROTATE is Reference You can use the Reference option by entering any angle at the keyboard or by picking two points on the screen You then type the angle to which you want the selected points to align Instead of typing the new angle you can also make one more selection It becomes the second point on a new angle using the first point selected as a reference for a base point SCALE SCALE also has a Reference option that s similar to ROTATE s but that may be even more useful I use it frequently to resize an image using a feature on the image that I know the size of this can be a photograph of landscape nautical charts a mechanical part or any thing else that s not to scale when inserted In the example in Figure 1 18 a National Oceanic and Atmospheric Administration NOAA nautical chart has been referenced as an image Scal
24. e object and duplicate objects on top of other objects It can clean up a mess of a drawing in a hurry see Figure 1 22 OVERKILL x j Object comparison settings F Ignore LAYERS Numeric fuzz 0 000001 I Ignore LINETYPE I Ignore COLOR I Ignore UNEWEIGHT Ignore PLOTSTYLE r Lines Arcs and Pines patally overlap T END to END Combine co inesr objects when aligned end to end Cancel Help Figure 1 22 Overkill dialog box OVERKILL doesn t always work correctly I ve found that it works best if you use it for one kind of cleanup at a time pline overlaps end to end even though the dialog box allows you to check every type at once Run it for each type separately to get the results you want
25. e used for all text with a height less than 3 This is a powerful function that you should absolutely understand how to use Let s walk through an example Let s say you have a drawing that has a lot of text Every text entity must stay in its current location but the height must change for all At one time that was a difficult problem but not any more Open the Properties palette and click the Quick Select icon the button with the funnel icon in the upper right corner Select text in the window and all the text entities are highlighted but not the MText entities Now change the text height in the Properties palette the height of all the text 26 CHAPTER 1 AUTOCAD PRODUCTIVITY Figure 1 17 changes You can change any of the properties of the entire group You could do the same for all the circles in a drawing or within a selection set and change their diameters CHAMFER and FILLET You can use either of these commands to clean up sharp corners or extend two uncon nected lines into sharp corners by setting their values to 0 As of AutoCAD 2006 you have the following option Hold down the Shift key while selecting the second line to create a sharp corner If yow re having trouble snapping to what you think is an intersection between two lines use FILLLET with a radius of 0 select the two lines and then try again If that works you don t have to take the time to zoom into the intersection to see if there s a gap You
26. ed the TIME function to see if one computer in an office really is slower than another or if it s just the perception of a frustrated user See Chapter 7 AutoCAD Scripts for a benchmark system to test computers with no user input The Save Options You can save drawing files using any of the following commands SAVE QSAVE SAVEAS and WBLOCK Each of these commands creates a DWG file in different ways but each has its own advantages SAVEAS When you select Save As from the pull down menu or type SAVEAS AutoCAD saves to a specified path with a specified name and makes the resulting path and filename the default The next time you use a save command including QSAVE Ctrl S this name and location will be used SAVE The SAVE command if it s issued by typing at the command prompt allows you to save to a different location or name without redefining the default drawing The Save option on the pull down actually calls the QSAVE command I change this whenever I upgrade AutoCAD I wish all Windows software had this kind of save option QSAVE The QSAVE quick save command automatically saves to the default location and name Ctrl S issues the QSAVE command WBLOCK WBLOCK is a save command It lets you save part of an existing drawing using one of three methods Select the option you want from the dialog box as shown in Fig ure 1 16 Because dialog boxes can t be used in AutoLISP programs you should know the command sequence
27. ed to create other blocks you can select Purge Nested Items starting with AutoCAD 2002 In earlier releases use the PURGE command as many times as there are levels of nesting in your block definitions in order to ensure that you re purging everything The Purge dialog box also allows you to select individual entities individually or in groups To select a con secutive list of entities select the beginning item hold down the Shift key and select the last item in the group The Ctrl key lets you add or remove items from the selection set See Figure 1 20 Many people still use the WBLOCK command as a quick and complete PURGE com mand That requires you to use the Entire Drawing option in the dialog box for WBLOCK or the option at the command line RENAME This is a great way to rename blocks dimension styles layers linetypes materials table styles text styles UCSs views and viewports You can use wildcards allowing you to FEATURE REVIEW ALL RELEASES 37 quickly change all names created when binding external references if you used the Bind Figure 1 20 option for binding which I recommend you do and not the Insert option For example if Purge All you bind an externally referenced drawing named STP123 dwg to a host drawing the block definitions have names like STP123 0 BLOCK1 ie ae STP123 0 BLOCK2 STP123 0 BLOCK3 STP123 0 BLOCK4 and O View tems you cannot purge STP123 0 BLOCKS If you want them to have the names B
28. ed to select an object for editing You can also control it visually using the Drafting tab of the OPTIONS dialog box I like a setting of 3 for this one as well LTSCALE In the past it was common to set this variable to the reciprocal of the intended plot scale If you use layouts properly however you shouldn t use LTSCALE to control the appear ance of linetypes because it s global and affects all lines in a drawing Instead set LTSCALE CELTSCALE and PSLTSCALE all to 1 and ignore the appearance of your line types until you set up a layout With PSLTSCALE set to 1 your linetypes scale automati cally in Paper Space so they plot the same regardless of the ZOOM factor used for the viewport in which they appear Some people don t like drawing in the Model Space tab unless their linetypes display cor rectly don t think it should matter If you put entities representing each linetype on a differ ent layer and use different colors for those layers you can easily identify the type of line it represents without seeing the segments Once you have a layout everything will look great 34 CHAPTER 1 AUTOCAD PRODUCTIVITY If some of your entities have linetypes that aren t scaled to your liking instead of changing that with LTSCALE use PROPERTIES to make changes to each individual object in a viewport in the layout Linetype problems are often the result of confusion between metric and imperial units If you need an LTSCALE of
29. for WBLOCK When issued from the command line with FILEDIA turned off the WBLOCK command allows you to make the same selections See Chap ter 5 Symbols Tables and Fields for more information on the WBLOCK command Backup copies The best method for making backup copies to removable drives CD flash DVD as you re drawing is to type the SAVE command at the command line or use the Send To function of Windows Otherwise you redefine the default name and location Right click any filename in a windows file management dialog box to select Send To You can add a location by creating a shortcut and placing it in the folder C Documents and Settings username SendTo Replace username with your login name See Chapter 2 Managing Your System for automated backup techniques GROUP The GROUP command should be used more often in my opinion It allows you to name a selection set so that you can use it again Once a group is created you can type FEATURE REVIEW ALL RELEASES 25 G at any selection prompt followed by the name of the group you created make the names short and memorable However the group must be selectable You can change whether a group is selectable using the Group dialog box PICKSTYLE The settings of the AutoCAD variable PICKSTYLE determine how other members of a group are treated including associated hatch patterns whenever any mem ber of the group is selected PICKSTYLE has four settings that you can toggle
30. full UNDO feature None disables U and UNDO commands One limits U and UNDO to a single operation BEgin and End BEgin and End cause a group of commands to be treated as a single com mand for the purposes of U and UNDO A group once ended is always treated as a single indivisible operation This is useful when you re writing an AutoLISP program Place an UNDO BEgin at the begin ning of the program and an UNDO End at the end If the user doesn t like what the program did it only takes one U to undo it Otherwise a separate UNDO is required for each step exe cuted by the AutoLISP program Mark Mark makes a special mark in the undo information to which you can later back up with the Back option If you re about to go off on a design tangent you may want to set a mark with UNDO so you can return to that point quickly if the tangent doesn t work out Number Number default is 1 specifies the number of preceding operations to be undone UNDO 1 is the equivalent of the U command When you use a different value 20 for example 20 operations are undone at once Typing REDO restores all 20 Using this option allows you to search back through the drawing history only during the current editing session for a specific point in the design process by typing in large values Don t forget to save the drawing before doing this You can click the down arrow next to the Undo button to see a command history and select the command you
31. have noticed that Z isn t displayed as an option It s a hidden option of UCS 2 Select the two endpoints of the object in this case a spline to indicate the angle of rotation Any time you re prompted for a distance or an angle in AutoCAD you can select points on the screen instead of typing them in Doing so is both fast and accurate When you start cre ating your own commands in AutoLISP you can use specific functions to make your pro grams behave the same way 3 Run the ARRAY command at the command prompt AR and select the spline you want to array at an angle 4 Press the Enter key at the Enter the type of array Rectangular Polar lt R gt prompt 5 Specify one row and four columns and you ll be prompted to give the distance only between columns 6 Select the two endpoints of the spline again to give the exact distance 7 Use the UCS command to return to the World Coordinate System WCS 16 CHAPTER 1 AUTOCAD PRODUCTIVITY Figure 1 7 Arraying the repeatable pattern Because WCS is the default you can type UCS and press the Enter key twice once to execute the command and once to accept the default Polar Arrays Geometry with a repeated angular pattern is often found in mechanical applications and sometimes in architectural and civil applications To create polar arrays efficiently avoid repeating the same set of editing operations for each feature arrayed Start by identifying a repeatable pattern
32. hrough the layers Like CHSPACE LAYWALK is now a native command in AutoCAD 2007 TXT2MTXT TXT2MTXT is used to combine individual lines of text into a single MTEXT object It doesn t format the final result as individual lines so you almost always need to do some editing but if you want to group text from older drawings into a single object it s nice FLATTEN I ve recommended this command to a lot of people in companies that do civil design They call me because they re having trouble with a drawing from someone else Object snapping to endpoints produces odd results because it turns out the elements aren t all at the same elevation FLATTEN quickly and thoroughly places every object at an elevation of zero MKSHP and MKLTYPE These commands give you the ability to create complex linetypes those containing text or shapes This process requires that a shape be created first MKSHP and then the linetype MKLTYPE LAYMERGE I often advise new users and companies to use as many layers as they may need so they ll have control over the related elements of a drawing Sometimes this results in too many layers which is always easier to fix than too few When you do have too many layers this command lets you put them together into one This is another of the Express Tools that have become actual commands DIMEX and DIMIN These are related commands that allow you to export dimension styles and then import them into a different drawing You c
33. ing it using the Reference options involves the following steps Issue the SCALE command Select the edge of the image Give a base point Type R or use the down arrows to select Reference as shown Select a start point In this example the latitude line showing 17 is the first point in E Co oat Select a second point In this example the latitude line showing 18 is the second point 7 Type 1 for one nautical mile the base unit of this drawing Because the distance from 17 to 18 is one minute of latitude which represents one nautical mile on the earth the image scales correctly FEATURE REVIEW ALL RELEASES 29 UNDO The UNDO command displays the following options at the command prompt Auto Control BEgin End Mark Back lt Number gt Auto Auto requires an additional specification of On or Off When Auto is on any opera tion taken from the menu no matter how complicated is treated as a single command reversible by a single U command Back Back takes the drawing back to the state it was in when the most recent mark was entered If you don t enter a mark the drawing goes back to the beginning of the editing session AutoCAD automatically places marks when some commands are used but nor mally you must place them yourself You can place multiple marks and UNDO each Control Control limits the UNDO operation or disables it completely It offers the follow ing options All enables the
34. ize layer naming across disciplines See Chapter 4 Applying Graphics Stan dards for more information Set All Properties to ByLayer Unless you have a good reason avoid the urge to use multiple colors linetypes or line weights on a single layer If you get a drawing from someone who has done this use AUTOCAD BEST PRACTICES FILTER or QSELECT to select and move objects to different layers and then change their properties to ByLayer Good reasons may include the desire to create a symbol or detail that contains multiple linetypes and colors Although this can be done by using objects on different layers many users prefer to have all elements of a block definition reside on a single layer so only that layer controls the appearance of the block In this case you can apply a specific color or linetype to an element before including it in a block definition 7 8 CHAPTER 1 AUTOCAD PRODUCTIVITY LAYER MANIPULATION Consider the following example from a residential floor plan Layer names all begin with a field that designates the floor of the residence FL1 FL1 DIM FL2 FL2 DIM FND FND DIM Each floor has a number of associated layers for hidden lines center lines dimensions appli ances electrical and so on Because the layer names are uniform you can use the following syntax either at the com mand prompt or within a menu to make the following changes to the layer Thaw all layers Set layer FL1 as the
35. key you get a joystick pan not that useful but kind of fun 36 CHAPTER 1 AUTOCAD PRODUCTIVITY Because holding down the middle wheel allows panning in all directions the Windows scrollbars aren t useful and often get in the way Turn them off under the Display tab of the Options dialog box and you ll get a 4 percent increase in screen area If you paid 400 for your monitor that s like getting 16 just for changing a setting VTENABLE View Transition Enable AutoCAD 2006 added a view transition feature that smoothly changes magnification or location when zooming or panning This replaced the abrupt transitions of prior releases Some people love it and some people don t VTENABLE allows you to turn it off for everything for panning only for zooming only for scripts only or for some combination The VTFTS and VIDURATION variables control the threshold and speed of the transi tion Personally I turn it off to speed things up a little Utilities Utilities allow you to do things like rename files and purge unused layers There are just a few things here but one that could be a huge timesaver is the use of wildcards in the RENAME command particularly when you bind an XRef PURGE The PURGE command is used to selectively remove unused layers blocks styles line types and dimstyles You can do this by name or using the Purge All option ALL at the command line If your drawing has nested block definitions blocks us
36. l it up later This approach reduces the number of regenerations necessary It s particularly useful in 3D drawings and some people use this feature for plotting a specific view If you haven t ever tried sav ing named views try it You ll be surprised at how useful it can be particularly when using AutoCAD sheet sets VPORTS This function is essential in 3D drawing and often useful in 2D drawing as well It allows you to divide your screen in Model Space into multiple views In 3D this permits you to create geometry while seeing it in a front top right side and iso view You can then have a different UCS in each viewport and get a different view of the same geometry To create a set of standard views for 3D select the 3D option in the Viewports dialog box Don t forget to use the SAVE option to save a configuration you ve set up Don t con fuse saving viewports with saving views You can restore saved views within any Model Space viewport and then save the viewport configuration Now whenever the viewport configuration is restored it will contain the views exactly as they appeared when the view port was saved The Middle Scroll Wheel Roll the middle wheel away from you to zoom in or toward you to zoom out The incre ment is controlled by the variable ZOOMFACTOR the larger the value the bigger the jump when using the wheel If you hold down the scroll wheel you can pan If you hold down the wheel while holding the Ctrl
37. l maintaining accuracy That efficiency isn t merely the result of being fast with a mouse and keyboard it s the result of planning strategies for approaching each new object to be drawn And of course you must be able to get information from the drawing to check the accuracy The following suggestions may improve your speed and accuracy in drawing and improve your ability to get information from a drawing quickly COMMAND LINE VERSIONS OF COMMANDS One technique for becoming more efficient with AutoCAD is to type aliases and commands at the keyboard If you can t type you may be out of luck but when watch keyboard jockeys use AutoCAD see countless places where they save a few seconds here a couple of seconds there and pretty soon it adds up to real time But what happens if the command brings up a dialog box You have to wait for the dialog to display grab your mouse make some picks click OK and get back to work It may be faster if you don t have to deal with a dialog box and many AutoCAD com mands have both a dialog based version and a command line version When they do you can issue the command line version by placing a minus sign in front of the command name or its alias for example AR or ARRAY This behavior is in AutoCAD to protect legacy applica tions written by users of past releases but you may find it more efficient than toolbars tool palettes or pull down menus Knowing how to bring up a command line versi
38. lection DTEXT Most justification options are logical Every line of text has four vertical locations for justi fication Top Middle Baseline Bottom in that order The Bottom is a line running through the lowest point on a lowercase letter with a descender j g p y These locations are shown in Figure 1 14 The Justify options of DTEXT are Align Fit Center Middle Right TL TC TR ML MC MR BL BC BR The two letter combinations match the locations TL is Top Left ML is Middle Left and so on Extracting Information from Drawings You can use geometry created in AutoCAD to get information accurate to 15 decimal places However the information you get out of AutoCAD is only as good as the accuracy of the geometry you create Following are some tips on using inquiry commands AREA It s easier to work with circle pline or region entities when determining areas particularly if you re trying to add or subtract areas to get a final total This section will give you some advice about using other entities to create plines or regions so you can easily find their areas Figure 1 14 Top Understanding Middle Baseline Bottom Text justification Left Center Right DTEXT justification options 22 CHAPTER 1 AUTOCAD PRODUCTIVITY PEDIT You can use the PEDIT command to create a closed pline from several line and arc seg ments To do so issue the command pick one of the lines answer Yes when asked if
39. n object relative to another object See Figure 1 12 Extension 0 803 lt 27 97 Even better play with the Temporary Track Point osnap until you understand how to use it because it allows you to chase points all over the screen by typing TT prior to acquiring a tracking point The new tracking point is temporary until you actually select it I use TT a lot and if you haven t figured it out it s worth trying The symbol can be used by itself to select the last point you entered Using CIRCLE and FILLET to Create Tangent Arcs Another common shape involves tangent arcs The quickest way to create an inside concave arc between two circles is to use the FILLET command with the proper radius set However an outside convex arc can t be drawn between two circles or arcs using FILLET You must use the CIRCLE command with the TTR option and trim out the unwanted portion of the circle The location of your cursor on the circles when you select tangent points determines whether a concave or a convex arc result See the Deferred Tangent tooltip in Figure 1 13 FEATURE REVIEW ALL RELEASES 21 Figure 1 13 eas Circle TTR for i NEI n Pa M n tangent arcs One overlooked feature of the FILLET command is its ability to quickly close two par allel lines with a tangent arc Select both lines and AutoCAD will calculate the size of an arc that it will use to join them on the end nearer your se
40. ng the Dimension Style Manager dialog box You don t have to know all of them but there are two you should understand DIMASSOC This variable was added to AutoCAD 2002 to control associative dimensions It replaces DIMASO but not completely because earlier drawings can be opened in current releases When an earlier drawing is opened the setting for DIMASO is used to determine the value of DIMASSOC 32 CHAPTER 1 AUTOCAD PRODUCTIVITY DIMASSOC has three settings 0 Dimensions are exploded as they re placed which is a bad idea unless you have a very good reason 1 Dimensions have the traditional defpoint association but they re not associated with objects and aren t connected to Model Space when a dimension is placed in Paper Space 2 Dimensions move with objects and reflect true size when placed in Paper Space DIMSCALE This variable controls all size dimension variables such as DIMTXT DIMASZ DIMEXE DIMEXO DIMTVP DIMTSZ and DIMGAP In the past for Model Space plotting DIMSCALE was set to the reciprocal of the plot scale to be used If plotting will reduce a drawing 48 times to fit on a sheet of paper you must first increase the size of the dimen sions 48 times so they ll be readable DIMSCALE is set to 1 if dimensions are placed in Paper Space which I don t recommend The system that I do recommend is to place dimensions in Model Space and to plot from Paper Space For that purpose setting a
41. nsive standards that apply to all of them I ve trained people who use AutoCAD to design quilts hearing aids doll clothes houses barns commercial buildings M16s sub marine hatches and the myriad components of machinery But there are some founda tional rules that represent a consensus among serious users of CAD You ll find exceptions to these rules of course but think of them the way you think of the rules for dimension ing drawings You follow them if possible The fact that a rule has rare exceptions doesn t reduce its value as a guide You certainly follow the rules requiring you to drive on the proper side of the road all the time except when a dog darts out in front of you or the road is washed away by a flash flood or you re passing someone So here are some of my rules for using AutoCAD Draw Everything Actual Size Unless you have a very good reason not to draw everything at its actual size Even details can be drawn full size if you use layouts They may not look right to you in the Model Space tab but you can display them in Paper Space viewports and give them any scale you want At one time you would have used the SCALE command and then set DIMLFAC to compensate for dimensions but that s not a good idea now You know why At some point you ll forget that your dimension style is multiplying every dimension by 2 or you ll dimension a detail and forget to change DIMLFAC and all the dimensions will be half their ac
42. o makes it much easier to use stan dard sized sheets of material during construction For mechanical parts use increments of 2mm or 0 1 inches if possible METRIC IS EVERYWHERE I ve been predicting since 1976 that the U S was about to go fully metric keep making that prediction and l m getting less and less wrong That may not be as good as being right but it s possible that you ll have to deal with the metric inch conflict at some point I ve assisted both mechanical designers and architectural designers in converting existing designs from inches to metric and if this is done as a hard conversion it often results in dimen sions that aren t logical to people who are used to working in the metric system Sometimes that can t be helped it may not be possible for a precision mechanical part to be redesigned to use even values It may be possible however for an architectural design to be soft converted to millimeters yes millimeters without any ill effects Does anyone in the Architecture Engi neering and Construction AEC field use metric units Well yes The whole rest of the world does and some companies in the U S are beginning to find that out for example cabinet makers whose cabinets won t fit into the space available except in U S houses and plywood makers who have no market for 48x96 sheets anywhere but here In one case a log home builder in Maine sold a home to a company in Japan The builder boxed it up put i
43. objects than you want The TXTEXP Express Tool can explode individual pieces of text into vectors The results aren t always pretty but I ve used this technique successfully to create cutting tool paths for CNC machines used to mill letters in either metal or wood The results differ between SHX fonts and TTF fonts Shape fonts which are vector based are exploded into line segments whereas TrueType fonts are exploded into closed polylines Usually a single letter requires multiple closed polylines that can be edited into a single outline You can form 3D block letters by using TXTEXP to explode a TrueType font and then using EXTRUDE to create 3D solids out of all the segments used for each letter Use UNION to cre ate a single solid OFFSET This command has always had two options Distance and Through The Through option allows you to offset an object through a selected point even if the object isn t long enough to actually pass through the point AutoCAD 2006 added some nice features to OFFSET You can offset an object onto the current layer You can also elect to erase the source object after using offset That sounds like it would just become the MOVE command which it would except that a multiple option was also added that lets you continue picking through points or offsetting the same distance multiple times OOPS People use UNDO sometimes when they really should use the OOPS command OOPS can be used at any time to restor
44. of points using GPS equipment to map the location of sewers drains manhole covers and so on The problem he had was that all the points and all the text were placed on one layer The text height was so large that the text overlapped and was unreadable See Figure 1 3 To fix the problem I did the following 1 I used QSELECT to select all the points and put them on their own layer which I immediately locked to protect the valuable locations generated by the GPS software 2 Iused QSELECT to select all the text height 294 and change its height to 5 so it would be manageable Figure 1 3 aT Using QSELECT App to Entredrawing gt BI Obiectpe fet Properties Operator Widcard Match X Vale 4 How to apphr Include in new selection set Exchade from new selection set JT Append to curert selection set coed Heo 12 CHAPTER 1 AUTOCAD PRODUCTIVITY 3 I used QSELECT to select all text containing a front slash all the dates and put them on their own layer This required using the wildcard match operator nice to know some DOS By placing in the Value window you get all text containing a front slash anywhere in the string Create Tool Palettes to Enforce Standards Using AutoCAD DesignCenter ADC you can create a tool palette that contains all the blocks from a symbol library drawing with a single selection Locate the drawing in the browser wind
45. on Never Override Dimension Values When you re adding dimensions to drawings it s tempting to type in the correct value when a dimension is wrong Unless you absolutely don t have the time to do it redraw the geometry so it s correct and then add an associative dimension Otherwise you and everyone who ever uses your drawing will assume it s correct with potentially dire results If you do override a dimension because you just can t help it then make sure you flag the change or note it so you can go back and re create the geometry later when you have time When I m dimensioning architectural plans set precision to an increment of 256 in the Pri mary Units tab of the Dimension Style dialog box That s ridiculously small for a dimension but by using such a small increment of precision know immediately if there s an error in the geometry as I m adding dimensions If there are no errors the proper dimension value is dis played If you set the increment to a whole number for example small errors are masked by being rounded to the nearest inch HELP SYSTEM I m not exaggerating when say answer many questions from confused users by bringing up the AutoCAD Help system often while I m on the phone with them The most recent was a call from a frustrated user who was using AutoCAD 2006 to edit text in a vertical title block The version of AutoCAD they had upgraded from displayed the text horizontally but
46. on of a command is a godsend when you write AutoLISP programs You can check the sequence for creating layers for example by typing LA or LAYER to avoid the dialog box and see the prompts Speaking of the LAYER command let me use it as one example of efficiency When need a new layer say one named newlayer for something I m about to draw almost always type something like this laitmtnewlayer _ just timed it It took me six seconds Newlayer is now the current layer and I m drawing away did the same thing using the Layer Properties Manager dialog box and it took me 16 seconds You may see that as saving only 10 seconds I see that as a 267 percent improvement in my efficiency This technique doesn t suppress all dialog based commands If you want the command line version of the SAVE command for example you need to first set the variable FILEDIA to 0 Then typing SAVE no minus sign needed won t display a dialog box but will give you save options at the command prompt 14 CHAPTER 1 AUTOCAD PRODUCTIVITY Rectangular Arrays When youre creating a rectangular array it s easier than you think to confuse columns and rows when you re asked to specify their distance Columns are vertical and the icon illustrates that in the dialog box Keep in mind that the distance between rows and columns is the distance from a point on one item to the same point on the next item P Figure 1 5 Precision array A rec
47. ow of ADC right click it and select Create Tool Palette as shown in Figure 1 4 Once you ve created a tool palette you can use it to enforce standards by setting the properties of any object on the palette including the layer it s on all tools the scale blocks and hatch patterns and rotation angle blocks and hatch patterns To adda hatch pattern use ADC to locate the file ACAD pat or ACADISO pat and drag and drop a pattern to the palette Feature Review All Releases One of the difficulties with an application as complex as AutoCAD is that everything seems to change with each release It can get a little discouraging Why learn the nuances of anything when that knowledge may be worthless in 12 months And if you do dig into a release and learn to use it productively can you keep doing those things after the next release The fact is many things about AutoCAD haven t changed over the years including fundamentals like the underlying Cartesian coordinate system the basic command struc ture the way menus and toolbars work the methods for creating and modifying most objects and how files are saved This section reviews the functionality that has been fairly Figure 1 4 Creating a tool constant in AutoCAD across many releases and is likely to stay that way No matter how palette from a much things change youll still be able to save a specific screen display using the VIEW symbol drawing command in fact that command ge
48. rate drawing You or your company have probably invested upwards of 7 000 to put you in an AutoCAD seat so why not produce as accurate and useful a drawing file as possible AUTOCAD BEST PRACTICES 5 6 CHAPTER 1 AUTOCAD PRODUCTIVITY Use the Help System The AutoCAD Help system has become one of the best Help systems available in any soft ware If I had to identify one AutoCAD feature as the single most underused this is it Pve gotten many phone calls from people who have an AutoCAD question that I answer by simply going to the AutoCAD Help system Use it It keeps getting better and better It s a model for what a Help system should be Use Blocks as Often as Possible Blocks can dramatically reduce file size allow you to quickly update large amounts of work and make your drawings more consistent Any time you create a symbol standard detail title block or other collection of objects that you may ever want to use again con sider creating a block definition Once you ve used a block don t explode it unless you have a good reason This is espe cially true for dimensions Once you explode it the block entity no longer exists You lose the ability to update the dimensions and you increase the file size sometimes dramati cally Dimensions will no longer update values when you modify geometry and you can t update dimension appearance with changes to dimstyles Don t explode hatch patterns either for the same reas
49. rget that we created something quickly by sketching and then saved the file It s quicker to use the accuracy tools built into AutoCAD than to draw by eye so why not use them Set Text Height to 0 If you set the height to a fixed value when creating a new text style the text can be used only at that height no matter how you set the text height in your dimstyle Setting a height of 0 gives you control over text height every time you enter the height If you can t read a dimension because the text is too small but you can see the arrowheads you ve specified a fixed height in your text style 9 10 CHAPTER 1 AUTOCAD PRODUCTIVITY Don t Use the Name Standard The name Standard is used as a default name for the text style dimension style table style and probably a few other things in AutoCAD It s misleading because it s a standard only in the sense that it always shows up in an AutoCAD environment Never does the name represent a real standard in any discipline To avoid a nasty surprise down the road build a template file that banishes Standard as a name for anything I suggest naming text styles for the fonts they use If you set their height to 0 you won t need all those Romans48 type names Romans will work fine For dimensions give the styles names that represent their disciplines or the name of the client For tables use names that represent their use Or use the names of your favorite pets just don t call
50. select a point inside the circle but outside the lines Figure 1 8 Using BOUNDARY for quick shapes 18 CHAPTER 1 AUTOCAD PRODUCTIVITY POLAR OSNAP OTI Figure 1 9 New shapes from regions ALTERNATIVE TO PEDIT You can create regions with the BOUNDARY command or with the REGION command Either way you can also use regions to create complex objects quickly by using the SUBTRACT INTERSECT and UNION commands The shape shown in Figure 1 9 was created in under one minute actually 38 seconds To create regions from existing closed plines or circles use the REGION command and select the objects You can create a new object using SUBTRACT UNION or INTERSECT and that object is also a region If you need to work with individual lines or arcs use the EXPLODE command to break the region into entities If you have trouble understanding what a region is think of it as a flat 3D object with a thick ness of 0 The 3D Boolean editing commands will work with any region the REGION com mand can be useful for other applications as well including creating floating viewports in a layout Drawings with Interior Angles For many drawings you know the length of each line and the angles between lines How ever you probably don t know the absolute angle of each line in the X Y plane angle from 0 East There is a strategy for doing drawings of this kind it involves recognizing that supplemental angles form a straight line 18
51. t s not unusual to want to find the area of an object with a large number of features removed It s easy to miss one or more objects in the process The quickest way to get a total area when you have many areas to subtract is to create regions If all the objects are circles or closed plines you can do this with the REGION command If the shapes are composed of anything else lines arcs overlapping segments use the BOUNDARY command Once all the shapes are regions use the SUBTRACT command to create a single region Then you can select a single entity when using the Object option of the AREA command FEATURE REVIEW ALL RELEASES 23 In Figure 1 15 it took 25 seconds to get the total area of the object with all internal shapes removed Here are the steps 1 Create regions from the existing geometry using the BOUNDARY command 2 Use the SUBTRACT command to remove the holes from the large object by selecting them all with a window 3 Use the Object option of the AREA command and select the resulting region You can also find the area as a property of the region in the Properties palette DIST The DIST command gives you an accurate distance if you use object snaps to pick the points It s also the quickest way to get an angle in the X Y plane Pick the points in the proper order or the angle will be off by 180 To get the angle between two lines use DIMANGULAR DAN The lines don t have to exist you can select three points
52. t on a container ship and then got the fax What the heck are these numbers and how soon can we get drawings in millimeters When they contacted me suggested that they convert their shop drawings to millimeters by changing DIMLFAC to 25 4 and then setting DIMRND to 2 All dimensions were then in whole even millimeters Nothing was off by more than one millimeter so the design wasn t compromised but the drawings looked better to the Japanese crew who had to read them Imagine how confusing it must be to see 7 8 when you re used to values like 2356 AutoCAD Best Practices I ve been training people to use AutoCAD for technical graphics and design since the late 1980s At that time I frequently got resistance from drafters and designers who felt I placed too much emphasis on absolute accuracy They would point out that once a draw ing is plotted the absurd 15 decimal places of precision that AutoCAD uses for calcula tions become meaningless Once you plot a drawing even significant errors are difficult to detect as long as you carefully replace any key dimensions with those you typed in I believe all industries that rely on computers for design and documentation should share common standards when using CAD software In this section I offer advice on accuracy and other aspects of AutoCAD that should be standard practice across all disci plines If you understand AutoCAD it s faster to produce an accurate drawing than an inaccu
53. tangular array can be created at any angle by selecting the Angle Of Array option in the Array dialog box even if you don t know the angle Suppose you want to array the shape on the left in Figure 1 5 to form the shape on the right In the example both the angle and the size of the object are randomly assigned In other words you don t know the exact size or angle and you can t estimate because you want the result to have no gaps or overlaps of the objects as they re arrayed You can approach this situa tion using two methods one of which works with either the command line version or the dialog box version of ARRAY DIALOG BOX ARRAY To create the shape in Figure 1 5 follow these steps at an angle l 2 3 4 Figure 1 6 Array dialog box Run the ARRAY command pick the Select Objects button and select the spline object Enter 1 for the number of columns and 4 for the number of rows Pick the Angle Of Array button shown in Figure 1 6 The dialog box will close temporarily to allow you to select two points in response to the prompt Specify angle of array Using the Endpoint object snap select each end of the spline Doing so returns an angle and places that value in the window Bectangular Array O Polar Array Rows 1 Columns Offset distance and direction Row offset Column offset Angle of array 1 By defauk if the row offset s negative Y rows are added downward If the column offset is negati
54. ts more and more F SHAFT OWG general AutoCAD features big and small that a lot of EN SYMBOLS DWG tay e797 a a Smaa E useful with the development of sheet sets There can be Folders l Open Drawings History DC Online Foda Lis aj a big difference in drawing efficiency between one user vs HZA 3DHOUSE2DWG af H 2 7 BASED Al A10 i Pe and another that has nothing to do with new features 4 DAPRAC DWG 3 i FRED3DH DWG Farlier in this chapter I discussed some rules and a LIBPROB DWG z afm mooeLowa L standards for using a CAD system Here I ll point out PANEL OWG Als A15 A16 A17 i f PANE users have missed They aren t secrets they just seem Search that way if you don t know about them And because Add to Favorites one Faves they aren t new features they don t show up in the New crane iced Haas Features Workshop as spiffy and new I think of these DESIGNCENTER C a elements as spiffy and old I don t care what release of IC Dan DA SMTC EGR240 SYMBOLS DWG Blocksf 43 Itemfs Blo AutoCAD you use there s something here for you FEATURE REVIEW ALL RELEASES 13 Drawing Efficiency At the heart of a CAD system is the ability to create accurate geometry Speed is always secondary to accuracy but it s possible for one user to be much more efficient than another in creating geometry while stil
55. tual size You have a complex enough job as it is keeping track of so many details Why not simplify your life by drawing everything the size it s supposed to be You re not at a drafting table Worry about how something will plot when you set up a layout Tve done a lot of training for different industries and have looked for situations where it was impossible to draw full size I haven t found an instance yet that couldn t be addressed using Paper Space At one shop I worked for two groups of designers who used AutoCAD had a difference of opinion about full size versus scale One group of designers thought they couldn t draw full size because they were designing long pieces with almost no detail along their lengths but a lot of detail at the ends They only drew the ends and then they broke the piece with a conventional break and plotted it for the fabricators The dissenting designers wanted to draw parts at their actual lengths so they could use them in assembly drawings without re creating them The solution I offered was to draw the pieces full length with proper end detail and then create a layout with two viewports to represent each end of the object As long as the two viewports were at the same scale and aligned they could be separated for a break sym bol to be added in Paper Space Even the dimension of the overall length was correct because it was in Model Space where I think it normally Sft6 X 1 16 or 2875
56. ure 1 10 BE polartracking Snap and Grid Pola Tracking Object Snap Dynamic Input settings I Polar Tracking On F10 Polar Angle Settings Object Snap Tracking Settings C Track orthogonally only Track using al polar angle settings New elete Polar Angle measurement Options Cancel Help Figure 1 11 Supplemental angles with relative tracking 20 CHAPTER 1 AUTOCAD PRODUCTIVITY Figure 1 12 Hover over an osnap to acquire a point You can change the default direction of angles from counterclockwise to clockwise to do this kind of drawing when it s easier to draw clockwise But if you change the angular direction from counterclockwise to clockwise to simplify drawing a single shape make sure you change it back to avoid confusion later Use From Auto Tracking or to Begin Drawing If you know that you need to start drawing an object a specific distance from an existing object use the From osnap and the symbol For example if you want to start a rectangle 10 units over and 45 units up from an existing endpoint do the following 1 Start the RECTANG command Use the From osnap Select the starting point es Fe he Type the coordinates for the first corner of the rectangle as 10 45 If you have POLAR OSNAP and OTRACK on and the Extension osnap is set as a running osnap you can pause over any running osnap acquire a temporary tracking vector and use it with direct distance entry to quickly draw a
57. using the Ctrl H keys the Ctrl A keys in AutoCAD 2000 and AutoCAD 2000i PICKSTYLE 0 allows selection of individual members of the group PICKSTYLE 1 allows the selection of the whole group but not boundaries PICKSTYLE 2 groups the selection of hatches with boundary objects PICKSTYLE 3 allows the selection of whole groups and group selection of asso ciated hatches with their boundaries If you find that a hatch boundary is erased when you erase the hatch check your PICKSTYLE setting It s probably set to 3 Edit Commands One of the most underused editing functions in AutoCAD is the Properties palette Some editing functions can be used in ways they weren t necessarily designed for and there are other options that a surprising number of people overlook most notably the Through option of the OFFSET command and the Reference option of the SCALE and ROTATE commands PROPERTIES This command displays the Properties palette of selected entities If more than one object is selected the properties common to all are displayed Properties of similar objects can be changed simultaneously Using the Quick Select button you can filter out objects based on multiple criteria by applying each criterion once and then selecting the current selection set for the next appli L cation This is a great way to clean up problem drawings that you get from someone else You can change the layer of all text for example or the styl
58. ve columns are Tip added to the left E Select objects 0 objects selected FEATURE REVIEW ALL RELEASES 15 DISPLAY PRECISION Don t be fooled by the integer of 27 shown for the angle in Figure 1 6 The actual angle may be different Why Because the default precision for angle display is 0 which means all angles are rounded to a whole number for display purposes only If you change the angular preci sion using either the variable AUPREC or the Units dialog box you ll see the angle in this case is actually 27 37591770 This often fools people when linear distances are displayed as well Linear precision can be set with the LUPREC variable or the Units dialog box Display This doesn t affect the actual precision AutoCAD uses for calculations All calculations are done to 15 decimal places no matter how the results are displayed 5 Pick either the Column Offset or Unit Distance button which results in the prompt Specify distance between columns 6 Using the Endpoint object snap select each end of the spline once again Doing so returns a distance this time and places that value in the window Click the Preview button if you like the results you re done COMMAND LINE VERSION OF ARRAY You may decide to automate a process like this using AutoLISP In that case you need to follow these steps using the command line version of the ARRAY command 1 Run the UCS command and type ZH to rotate a UCS around the Z axis You may
59. want to go back to The Redo button has a similar command history 30 CHAPTER 1 AUTOCAD PRODUCTIVITY Figure 1 19 Rotated dimensions versus aligned LENGTHEN This interesting command can be used to change the length ofa line polyline or an arc It s the only way to quickly create an arc with a specific arc length To do that create the arc and use the Total option of LENGTHEN to change the total length to whatever you want LENGTHEN s options include the following DElta DElta allows you to add a specific amount to the length of an existing line or arc or to add a specific angle to the existing included angle of an arc Percent Percent allows a specific percentage increase in the length of a line or pline or the included angle of an arc Total Total lets you set a new overall length for a line a pline or an arc DYnamic DYnamic allows you to change the length of a line but not a pline or the included angle of an arc by picking a new point and watching it change lt Select object gt lt Select object gt gives the existing length or angle of a line or arc Dimensions Dimension styles are discussed at length in Chapter 4 because they re critical to applying technical graphics standards correctly Here I want to point out some aspects of the process of dimensioning that people often get wrong starting with a difference that almost nobody seems to understand aligned versus rotated dimensions Aligned vs Rotated
60. y be a good time to thank my mother for insisting that I take high school typing in 1967 an era when the manual typewriters used in classrooms had blank keys so you wouldn t hunt and peck The OPTIONS command see Chapter 2 Managing Your System allows you to set all drawing aids file search paths the appearance of the screen and the variables affecting saving and opening drawings and also lets you save these settings in a user profile The profiles can be exported for use on other computers There has been pressure over the years to eliminate the AutoCAD command line because it s seen by some people as outdated I ve always found this suggestion alarming because a key board jockey can be much faster and more efficient than a toolbar user with comparable skills For us keyboard users Autodesk s decision to make the command line one more optional aspect of the interface was a welcome response to this pressure APERTURE The APERTURE variable allows you to control how close you must be to an object meas ured in pixels when using an osnap It can also be set using the Drafting tab of the OPTIONS dialog box If you re having trouble isolating an object in a cluttered area try setting this value to a smaller size I prefer a setting of 3 If you re having trouble picking an object because you have to get too close to it try a larger size PICKBOX is similar but it controls the size of the box that shows up when you re ask
61. you want to turn it into a pline select the JOIN option and pick the other segments with a window Remember All segments must be touching but not overlapping You can t have segments on top of each other The resulting pline should be closed Use the Fuzz option of MPEDIT if your geometry isn t exact The variable PEDITACCEPT was added to AutoCAD 2005 If it s set to 1 the user isn t prompted with the question Object selected is not a polyline Do you want to turn it into one lt Y gt Instead the object is automatically turned into a pline It s possible that 1 will become the default setting in a future release ENTITY SELECTION When you use the AREA command it s easier to select objects than it is to pick points To find the area of a large object minus the areas of several smaller objects you can use the Add and Subtract options of the AREA command Pay attention to the command prompts Type AREAJAJ followed by 0H select the largest entities and then right click when you finish doing so adds the areas of all the objects you picked Type S to select the Subtract option followed by 0 for Object and select each object whose areas you want to subtract The alias for the AREA command is AA which doesn t follow the normal pattern used for other commands Why not A ARC and AR ARRAY are already taken RENDER RR is the only other alias with this format QUICK AREA CALCULATION FOR COMPLEX FEATURES I

Wiley AutoCAD: Secrets Every User Should Know

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