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AutoCAD FAQs - Answers


User Interface

  • Instead of the Plot dialog box and ASE dialog boxes, command prompts appear on the command line.

    The AutoCAD system variable CMDDIA controls the display of dialog boxes for the PLOT command and the external database (ASE) commands. Set CMDDIA to 1 to enable these dialog boxes: on the Command line enter CMDDIA, press Enter or Space, and enter 1.

  • >Prompts appear on the command line instead of the Open or Export dialog boxes displaying

    The AutoCAD system variable FILEDIA controls the display of file listing dialog boxes. Set FILEDIA to 1 to enable these dialog boxes. If FILEDIA is set to 0, you can still request a file dialog box to appear by entering a tilde ~ in response to the first prompt of the command you selected. Also be aware that if a file command is called from a script or AutoLISP/ADSRX/ObjectARX program, a command prompt appears instead of a dialog box.

  • When inserting a block or file containing attribute definitions, the "Enter Attributes" dialog doesn't display

    Two system variables control this. Make sure ATTREQ and ATTDIA are both set to 1 (not 0): on the Command line enter ATTREQ or ATTDIA, press Enter or Space, and enter 1.

  • Drawing files, layers, and blocks are no longer listed in alphabetical order in dialog boxes

    The system variable MAXSORT determines how many file names, layer names, blocks, linetypes, and so on, are sorted alphabetically in AutoCAD dialog boxes. This setting can be applied in the General tab of the PREFERENCES dialog box for the setting "Maximum number sorted symbols".

    Increase the value for MAXSORT. The default setting for MAXSORT is 200, which means up to 200 entries will be sorted in alphabetical order in list boxes. If the number of items in a list exceed 200, no sorting will be done. Keep in mind that a high setting for MAXSORT will use more memory, and as a result, sorting a large list of items will take more time. If you find that your list of drawings is becoming long, you might want to organize your drawings into different subdirectories instead of increasing the value for MAXSORT. For long lists of blocks and layers, periodically re-evaluate the need for all of them in order to maintain the number of items to a reasonable size.

  • Q: How do I delete empty layers?

    A: Layers in AutoCAD drawings can only be deleted when all objects that reside or reference the layers are removed. If a layer appears to be empty but PURGE will not remove it from the drawing, it may be that this layer is frozen in a paper space viewport, or it might be referenced by an object in a block definition.

    It is possible to remove a layer from a drawing by using the EXPORT command, which results in creating an ASCII DXF file of the drawing. Edit the DXF file in a text editor and rename all instances of the layer in the file, except the layer definition itself. Save the text file and use the IMPORT command to import the DXF file into a new drawing in AutoCAD.

  • Q: How do I open and work on more than one drawing at a time?

    A: You can open multiple instances of AutoCAD 14 on a workstation within the limits of system memory resources. Open a second AutoCAD session, and then open another drawing file in the new session.

    AutoCAD 2000 allows you to open multiple drawings for each session.

  • Q: How do I open a drawing file that was created with the automatic save feature (drawing has .sv$ file extension)?

    A: AutoCAD will only open drawing files that have the file extension ".dwg. Rename the drawing using Explorer or do this at a DOS prompt. If using Explorer, you will need to be sure the option "Hide file extensions for known file types" is not enabled. This option is found under the View pull-down menu under Options.

    Once the file has been copied or renamed, use the OPEN command in AutoCAD to open the drawing.

  • Q: Why are there smiley faces in the buttons on toolbars instead of icons?

    A: Button icons in the Toolbar or Toolboxes are replaced with smiley faces when AutoCAD cannot locate the path to the bitmaps for these buttons. This can occur when the menu template file (MNU) is manually edited after the toolbars have been customized. The changes in line spacing in the template file caused by manual edits can cause the menu resource and compiler files to "lose track" of the button definitions.

    In this case, open the menu source (MNS) file and menu template (MNU) file in a text editor, and copy and paste the customized toolbar sections from the MNS file to the MNU file. Then rename or delete the MNS, MNC, and MNR files. Use the MENULOAD command to reload the menu file using the template (MNU) menu file. The three compiled menus (MNS, MNC, and MNR) are recreated. As a result, the problem should be corrected.

    This problem can also occur if the bitmaps are not in the support path. Make sure the support path in the PREFERENCES dialog box includes the directory for the bitmap files. For example, if you moved a button from a custom toolbar to a toolbar that is part of AutoCAD's standard menu, you may need to edit the button file so that the bitmap file is saved somewhere in the support path. Follow these steps:

    1. After moving or copying the icon to a different menus toolbar, and while the Toolbars dialog box is still open, edit the icon by right clicking it again.
    2. In the Button Properties dialog, choose the Edit button.
    3. In the Button Editor dialog box, choose the Saveas button. Specify a directory found in the AutoCAD support path.
    4. Close the Button Editor, choose Apply in the Button Properties dialog, then close the windows and restart AutoCAD.
  • Q: Why do drawings that I open in AutoCAD Release 14 have tiny dots, which when closely examined turn out to be very short polyline segments?

    A: Previous releases of AutoCAD allowed the creation of a polyline object that had only one vertex or no vertexes defined at all. Certain older add-on applications would create these type of corrupt polylines for tracking data (there are a variety of improved methods for data tracking in Release 14). Also, in some earlier versions of AutoCAD, corrupt polylines could be created in some situations when breaking ellipses. Such an object has no geometric meaning, and would cause import and export problems between CAD applications.

    AutoCAD Release 14 identifies and corrects this corruption problem in drawings by adding vertices to any polylines with less than 2 vertices. If a polyline only has one vertex, then a second is added at the same location as the first. If a polyline has zero vertices, then AutoCAD adds a vertex at the origin point of the drawing (0,0,0). It is generally safe to delete these objects from your drawing when you discover them. If you are unsure, move them to a separate layer that can be turned off so that you can remove them from view.

  • Q: How can I make use of the middle button in my three button mouse?

    A: A pointer driver must be installed that supports three buttons. You can check this by selecting Control Panel from the Windows Settings menu, then the Mouse icon. Confirm that the middle button is not assigned to any function so that AutoCAD can use it.

    The middle button definition is defined in the AutoCAD menu file, in the ***AUX1 section.

    For example:

    ; <-- right button

    $p0=* <-- middle button

    If the middle button is still not working, check the Compatibility tab in the AutoCAD Preferences dialog box to make sure that "Priority accelerator keys" is set to Windows standards.

  • Q: How do I assign keyboard characters or function keys to AutoCAD commands?

    A: Edit the ACCELERATORS section of the AutoCAD menu file. See technical document TD104068 (4068) Mapping Accelerator Keys in AutoCAD Release 14 for an example of how to do this.


  • Q: When I select an object and press the DEL key, it is not erased. Also, the drag & drop feature for moving or copying objects doesn't work.

    A: You need to make sure that the Noun/Verb option is selected in the System Options. Normally in AutoCAD you select an action (verb) such as Rotate or Erase and then select an object (noun) to apply that action to. Some editing functions - such as MOVE and ERASE - allow you to first select the objects, then the action. This is called Noun/Verb selection.

    To turn on Noun/Verb Selection, open the System Options dialog by selecting Tools > Options in the menu bar. Click on the Selection tab and make sure the Noun/verb selection box is checked. Note that this option also controls the list of actions available in the right-mouse click short-cut menu as well as drag and drop functionality for moving and copying objects.

    Noun/verb selection is controlled by the PICKFIRST system variable, where PICKFIRST = 1 turns on the feature.

System Settings

  • Q: How do I set my default drawing directory?

    A: A default drawing directory is specified as a working directory in the "Start in" option in a Windows shortcut icon. Create a shortcut icon for AutoCAD if one does not already exist. Do this by running Explorer and navigating to the directory where the AutoCAD executable file acad.exe resides. Highlight the "ACAD" application and drag it onto the desktop. Press the right mouse button to view the menu for the shortcut icon you just created, then select Properties. Click the Shortcut tab at the top of the dialog box. Enter the desired directory in the "Start in" text field, then choose OK.

    Whenever you start AutoCAD using this shortcut icon, the directory you set will be the default directory when you use the OPEN command and for other commands that allow you to select files. Note that you can create any number of shortcut icons with each one having a different default directory.

  • Q: How do I make a spiral, a spring, or a screw thread?

    A: First, use an AutoLISP routine such as spiral.lsp to create the spiral path you need. Then use the EXTRUDE command with a reference object, using the spiral as the path. You can also accomplish this with Mechanical Desktop® (MDT) or AutoSurf® by using the augmented lines approach. Create a sweep surface using augmented lines as the path. In MDT, use the SURFCUT command to create the solid.

  • Q: How do I copy dimension styles from one drawing to another?

    A: There are several ways to do this.

    1. To set up a particular dimension style to use repeatedly in new documents, create the style in a blank document and save the document as a Drawing template (File ->Save As, and change Save as Type). Then when you create new documents you can reference the template document as the starting point and the style will be defined. Templates are also useful for quickly setting up other types of system variables which you want to be consistent across a collection of drawings such as layer styles, units, title blocks.

    2. To copy a particular dim style on a single-case basis, you can Xref the drawing containing the dim style of interest into the current drawing. Then use DIMSTYLE to create a new dim style based on the xref's style.

    3. Easiest of all, when using AutoCAD 2000: Open Design Center (Tools->AutoCad Design Center or Ctrl + 2). This tool allows you to browse and copy dim styles, block defs, layer defs, text styles from both closed and open drawings into a new drawing.

      • To copy a dimstyle from a closed drawing, click on the Desktop icon in the tool bar of the Design Center window; to copy from an open drawing, click on the Open Drawings icon.
      • Make sure the Tree View option is selected.
      • In the tree listing (left pane) of the DC window, navigate to the directory containing the drawing whose dimstyle you want to copy.
      • Click on the plus sign next to the drawing itself to view a list of drawing elements that may be copied; select an element type to see a list of defined objects of that type.
      • To copy one - for example a dim style - simply click and drag the desired dimstyle into an open document. The dimstyle can now be used or modified via the DIMSTYLE command.


  • Q: How do I set line thickness for plotted or printed output?

    A: There are several methods for applying thickness to AutoCAD objects.

    In AutoCAD 14, the most common approach for obtaining printed or plotted lineweights is to use the color used for objects on the screen, or to be more exact, the color number assigned to these objects when applying line thickness settings. From the PLOT dialog box, select the Pen Assignments option. For each color number in AutoCAD, locate the Width box under the Modify Values title on the right side of the Pen Assignments dialog box. The formula for selecting the correct pen width is the number of dots wide for the line to be drawn divided by the resolution of the device or <dots wide>/<device resolution>. AutoCAD will accept this formula in place of a raw value. For example, you can enter 1/300 and the correct decimal inch value will be calculated and entered into the Pen Width column.

    Some typical values are 1/300 for the HP LaserJet III printer series, 1/360 for the Canon BubbleJet printer series, 1/600 for the HP LaserJet IV printer series, and 1/720 for the new Epson Color BubbleJet printers. Because 1/600 and 1/720 are such small values, hatch patterns such as DOT may print but not be clearly visible to the human eye. It is best to enter 2/600 or 3/600 as the pen width in this case.

    AutoCAD 2000 now allows you to assign lineweights to objects, either by layer or on an object by object basis. For layers, open the layer properties dialog and select the desired lineweight from the Lineweight field. Note that when the LWT button at the bottom of the screen is depressed a representation of the lineweight will be displayed on screen as well as when plotting.

  • Q: How do I rotate raster objects since the Rotate option in the PLOT command has no effect?

    A: If a system printer is used to print the drawing, Raster or OLE objects in AutoCAD drawings can be rotated from the System Printer Setup dialog box. If an ADI driver is used to print the drawing, rotate the object before importing it into the drawing. Alternatively, you can use the DVIEW command's TWist option to rotate the view of the drawing 90 degrees. The OLE objects will not be rotated by this command.

  • Q: How can I print a drawing to a specific scale?

    A: The easiest way to do this is from a Layout (AutoCAD 2000). Prepare your drawing in model space as usual. Then click on a Layout tab. If this is a new layout, the Page Setup dialog will open. Otherwise, choose File->Page Setup. In the Page Setup dialog, choose the plotter and paper size options. Leave the plot scale as 1:1. Click OK. If necessary, create a viewport (frame) in the layout: View->Viewports->1 Viewport, and draw a rectangle for the viewport.

    To specify a particular scale, select the viewport by clicking on its boundary. Right mouse click and select properties (or choose Modify->Properties). Now either select a scale from the dropdown menu in the Standard Scale option box, or enter a value in the Custom Scale option box. Custom scales may be entered as decimals or as fractions. For example, if your drawing units are inches and you want to print at 1 inch = 100 feet (i.e. 1" = 1200"), enter a scale of 1/1200 (you can enter fractions as values and AutoCAD will automatically calculate the decimal value). The view of the drawing in the viewport will be adjusted to your new scale. To adjust the framing of the drawing, double-click in the viewport and use the pan and/or zoom tools until you have exactly the view of the drawing that you want.

    Note that zooming in the viewport will change the scale! To plot a specific portion of a drawing at a set scale, first pan and zoom in the viewport until your drawing is composed about how you desire. Then select an appropriate scale that is close to what you chose manually. For example, after panning and zooming you examine the viewport's scale property and see that it's 0.00085. This is very close to a scale of 1/1200 (1" = 100') or 0.000833. So you could choose 1/1200 as a fixed scale.

  • Q: How can I hide specific layers when plotting?

    A: To prevent layers from plotting, use the Layer Manager to either: a) turn them Off, b) Freeze them, or c) turn them off for Plotting. Layers turned off or frozen will not appear or plot. Layers turned off from Plotting will be visible on screen but won't be output to a printer.

    You can also set up individual layers to be frozen only in specific viewports. For example, if your drawing contains layers for both plumbing and electrical systems, you may want to plot only the plumbing layers some times and only the electrical layers other times. To do this, create separate layouts or separate viewports in a single layout: one for plumbing, one for electrical. Then, in each viewport you can set different layers to be frozen just in that viewport. Thus in the plumbing layout you would set electrical layers to "Freeze in Active VP;" and in the electrical layout you would freeze the plumbing layers. To hide one or more layers in a viewport:

    1. Open the layout that you want to plot.
    2. Double-click inside the viewport frame to activate it. The frame will appear as a heavy line and the status bar at the bottom of the screen will say "MODEL"
    3. Open the Layer Manager: Format->Layer or click the Layers icon in the Object Properties toolbar
    4. Select one or more layers that you want to freeze (hide) in the layout (i.e. not print).
    5. Click the "Active VP Freeze" symbol (2nd to last column in the Layer Manager) in one of the highlighted rows. All selected layers will be frozen—but only in the current viewport.
  • Q: How can I determine the surface normals of meshes created with the 3DFACE and RULESURF commands?

    A: Normals are determined by the direction in which a face is drawn in AutoCAD based on a right-handed coordinate system. For example, if you draw the face counterclockwise, the normals point outward. If you draw the face clockwise, the normals point inward. When rendering the drawing, you can disregard faces with normals pointing away from your viewpoint by checking the "Discard Back Faces" option in the Rendering Preferences dialog box. The AutoLISP routine re3dface.lsp can be used to revert the direction order for a 3D face.

By Allan and Mike

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