Wednesday, March 29, 2006


You can place superscripts or subscripts in your Mtext by cheating the Stacking options.

Mtext has several different ways to display fractions (or tolerancing.) AutoCAD calls this formatting stacking. By default, Mtext displays fractions entered with a forward slash as vertically stacked, fractions using the number sign as diagonally stacked, and fractions (or tolerances) with a caret as vertically stacked with no line.

Notice the last option. What would happen if we stacked something without a value on one side of the caret? Yep, we get a subscript or a superscript. Consider the following example Mtext:

To force stacking, highlight the caret and the text, right-click, and choose Stack from the menu. Notice in the example above that we place the caret before the subscripted text but after the superscripted text. Top and Bottom respective values are blank (that is, don't select anything.) For greater control over stacking options, select Stack Properties from the right-click menu.

Sunday, March 26, 2006

AutoCAD, Stop Helping Me!

Controlling the Insertion Units

New system variables were introduced with the advent of the AutoCAD Design Center (ADC) in AutoCAD 2002. When you drag and drop a block or drawing from the ADC into your current drawing, AutoCAD examines the values of INSUNITS in both the block and the current drawing and, depending on the value, automatically rescales the block appropriately.

For example: Using the ADC, if you drag a 2x4 light fixture symbol with an INSUNITS setting of 1 (Inches) into your current metric drawing which has an INSUNITS setting of 4 (Millimeters), the light fixture block is automatically rescaled by 25.4, converting it to the metric equivalent of this English sized light fixture.

Autodesk, in their finite wisdom, decided that this was such a clever feature they would extend it to all insertion operations in AutoCAD 2006. Now, when you INSERT a Block, or XATTACH a drawing, AutoCAD reads the INSUNITS of the source and target drawings and calculates a rescale factor for you. This rescale factor is then multiplied by the Scale you enter to yield the final insertion scale of the Block or Xref.

This can be handy, if you know about it and know how to make it work for you, but frustrating if you don't. So pay attention to the Block Unit area of the Insert and Xref Attach dialogs to see if AutoCAD is "helping" you determine the proper insertion scale factor. If the resultant scale is incorrect, adjust the setting of INSUNITS in both the source and target drawings before Inserting or Attaching it.

Some of the more common INSUNITS settings include:
0 = Unspecified (No units)
1 = Inches
2 = Feet
4 = Millimeters
6 = Meters

AutoCAD uses the values stored in system variables INSUNITSDEFSOURCE and INSUNITSDEFTARGET if INSUNITS is Unspecified.

Friday, March 24, 2006

A whole program in a single Tip: Autodesk Reference Manager

This application allows you to modify the paths to Xrefs in multiple drawings at once. This program runs external to AutoCAD. To launch it, choose Start > Programs > Autodesk > AutoCAD 2006 > Reference Manager
Use the Add Drawings button from the toolbar to add multiple drawings to the Reference Manager. The example below shows three drawings in the left pane. The right pane shows the reference types within these drawings: Xrefs, Plot Styles, Fonts. Note that there are four Xrefs in three Host Drawings.
Let's say you received these drawings and associated Xrefs from a consultant, and you filed the Xrefs in the Models folder, and the drawings in a Sheets folder. Now you want to change the Saved Paths for all the drawings at once. In the right pane, select the Xrefs that you wish to modify and click on the Edit Selected Paths button on the toolbar. Change the New saved path to be the Models folder, and click OK.

Think you're done, right? Not quite. You have to click Apply Changes to actually write the modifications back to the Host Drawings.

Note: Using the AutoCAD 2006 Reference Manager to modify the reference paths of AutoCAD 2002 drawings will update the DWGs to 2006 format. There is a 2002 compatible Reference Manager available. Contact your Division CAD Coordinator if you need this application installed.

Where Are My Parents?

Have you ever wanted to find what drawings a given drawing is referenced into? Say you have a floor plan background and you want to know what sheet files reference this background.

  • Open AutoCAD
  • Call up the Design Center
    Pull down menu: Tools > DesignCenter, or
    Command: ADCENTER
  • Click on the Search button to search drawings for desired criteria
  • In the Search dialog, Look for Xrefs, In desired folders, Search for the specific Xref name

All drawings in the designated folders that contain your Xref will be displayed in the results pane below.

Bonus Tip: You use this same method to search for drawings containing specific Blocks, Layers, Linetypes, Dimstyles, etc.

Thursday, March 23, 2006


AutoCAD's REVCLOUD draws a very nice revision cloud that somehow magically follows the cursor as you drag it around your screen, and when you get close to the start point, it automatically closes itself. This is pretty clever. But do you often wish you had a bit more control over its placement? Try this: Use the PLINE command to draw a desired bounding shape around what you're trying to cloud. Then use REVCLOUD's Object option to convert this Pline to a Revision Cloud.

Minimum arc length: 1' Maximum arc length: 2' Style: Normal
Specify start point or [Arc length/Object/Style] <object>: [Enter]
Select object: [select the polyline]
Reverse direction [Yes/No] <no>: [Enter]

Revision cloud finished.