The CAD Times

An AutoCAD Newsletter for CAD Users

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This month's tips and tricks...

Recovering a Damaged Drawing

Most of you know how frustrating it can be when dealing with damaged drawing files. Especially when you’re crunched for time and you feel like you're spinning your wheels trying to get the drawing open; or at least to stay open beyond 30 seconds.

But before we get into the ways to repair a damaged drawing, let’s look at why the drawings become damaged in the first place.

How Did the Drawing Become Corrupted?

Autodesk lists some of the reasons for drawing corruption including copying to a damaged hard disk or floppy, bad computer RAM, power surges, data lost in translation from other CAD programs and “crashing” (AutoCAD has unexpectedly shutdown).

My personal take on the matter you ask?

The little green devil guy from “Just for Laughs” has somehow infiltrated my hard drive, KNOWS I have a fast approaching deadline, and is kicking the hard drive sector where my precious drawing file is located.

But all the guesses in the world as to why “this is happening to me” really don’t matter; especially when you’re in a time crunch.

There is something you can do to help prevent disasters from happening though.

Prevention First

Make frequent backups of your drawings on another drive. This way if the file you are working on becomes damaged, you can pull-up a recent backup of the drawing. It’s a also a good idea to have your AUTOSAVE set to save to another hard drive at frequent increments (mine is every minute).

If your file does become corrupted there are a few things you can do to try to salvage your drawing; but note that there is no guarantee you will recover all or any of your drawing (so be sure to have good backups).

Recover a Drawing in AutoCAD

The first step in attempting to recover a “bad” drawing is to make a copy of the damaged file and it’s back-up file (.bak) on another drive. This way you will always have the original damaged file to work with after attempting the following recovery methods.

The RECOVER Command

When you attempt to open a drawing that AutoCAD recognizes as a damaged, you will receive a message indicating the file is corrupted.

AutoCAD then asks you if you wish to attempt to RECOVER the drawing. Click on YES and AutoCAD will commence its recovery process.

If AutoCAD successfully makes it through the recovery process (without crashing), you’re in luck!

Resave the recovered file and move on. If not, try these other recovery practices:

INSERT the Drawing into a New Drawing

Start a new drawing.

At the command prompt enter DDINSERT and browse to the location of the damaged drawing. Choose the corrupted file, then click OPEN.

Another pop-up menu will appear.

Make sure all the check boxes are unchecked EXCEPT for the explode option.

If AutoCAD successfully inserts and explodes your drawing, use the AUDIT command to attempt to clean up the damage.

The EXPORT Command

Another way of trying to get rid of potential corruption problems is to export the damaged file. If your file contains hidden problems that cause your drawing to crash, you may be able to get rid of these troubles by exporting the good portion of the drawing.

At the command prompt enter EXPORT. In the “Files of type:” selection box, be sure to select “Block (*.dwg)” and change the file name in order to preserve the original file. Click “Save” then enter a * to export the entire drawing.

Open the file you just exported to see if the corruption is gone.

Good luck!

Finding an AREA

There are times when finding the area of a floor plan, a property plan or even an irregular shape, such as the outline of a lake on a map, is required. AutoCAD has a couple of ways to help you determine the area.

Using the AREA Command

Command: AREA
Specify first corner point or [Object/Add/Subtract]:


Pick Points

By using the AREA command’s default option, you can pick points around the object to determine its area. This is useful for simple objects that don’t have a lot of points to choose.

Simply pick the desired points and hit . AutoCAD returns the area and perimeter.

Tip: AutoCAD also indicates the area in square inches and square feet, when your drawing units are set to either Architectural or Engineering (imperial units).

Choose the Object

By choosing the AREA command’s next option, “Object”, you can select entities such as polylines, circles and rectangles, and AutoCAD returns the area of the selection.

Using a polyline to define the area is one of the best methods for irregular shaped objects. Simply trace your object using a polyline.

Tip: Turn your OSNAP setting on to trace the object as accurately as possible.

Add or Subtract Areas

If you have more than one area that you need to incorporate into a total area, use the Add and Subtract options to have AutoCAD automatically calculate a running total.

Type A (Add) or S (Subtract) first, then pick your points or specify the “Object” option. You can then continue adding or subtracting areas within the same Area command until all desired areas have been incorporated.

Using the LIST Command

You can also use the LIST command to identify the area of a polyline, rectangle and circle with a single click.

Until next month :)