Expert: Bob - 10/6/2009

Question
I saved this CAD file which is about 67M in size and when I tried to reopen it it gets stuck at 98% then a message appears that "autocad cannot continue.." It does the same on my machine and other school computers. And it shows the drawing while opening it as if it is nothing wrong with it (other times when the file is corrupted it doesn't show any image). There are no other files (bak or $v$ that I can recover which would have the layers I need). If only I could recover one layer.. Is there anything I can do?

Thank you veruy much,
Brandusa

Answer
Hi -- the answer to the overall problem is in the title of your question. This file is not a CAD file, it's a herd of elephants, at 67 megs, lol - SORRY. We all tend to do that when learning.
It seems the drawing is so complex that AutoCAD places huge demands on your system while trying to re-create it on the screen, and crashes. Think of it as a regular garden tractor trying to move a mountain, if that helps.

Maybe no one tells students that errors in 3D objects, for instance, can increase file size very dramatically. Unless your drawing is a large complex of office towers with landscaping, for instance, it likely contains problems.  (and, of course, the drawings of the office complex would consist of smaller drawings Xrefed into the main drawing.)
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THESE ARE THE PARTS THAT KEEP ME FROM BEING ABLE TO COMMENT MORE CLEARLY ON HOW TO FIX THE FILE

Unfortunately, you made an important error by not telling me which release of AutoCAD, since a huge file like that must contain solids, meshes, etc --- which changed a lot in 2007 and again in 2010. I cant give much advice on how to make it smaller without knowing how it got to that size.

I am hoping this is not a 2D AutoCAD file, but a 3D file from AutoCAD Architecture, with a huge building, lots of textures and materials, etc --- even then it might be 5 times the correct size.

It would help if you would say, next time, "file of x size containing ABC object types, on a system w/ Zgigs processer, Qgigs memory, and DRWvideo card". Crashing can be about a corrupt file, and/or an inadequate machine for the size and complexity.

Also, by what you write, I cant tell if you are in high school or college, and what the course is, or what you are drawing, so I have to guess: that makes me potentially much less helpful.
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NEXT-- there are only "no .bak or $v$ files" because someone got rid of them, or unfortunately chose the settings that block them.  AutoCAD creates both by default. It would be good to figure this out for next time.

AND -- sorry your instructor did not teach you to "save as" every day or so, and not delete the originals until later. For example: I tell students to save drawing X done on May 11, as "drawing X May 12" the next morning when beginning work, and so on. (then the May 11 one still exists on May 14, when disaster strikes.)

AND --- its easy to get the layers from any drawing into another drawing -- just drag them in via Design Center.  Unfortunately, I don't think you mean "layers", but "objects that are on certain layers". Layers brought from another drawing contain no objects, unless you copy or create objects there.

Depending on the release of AutoCAD, a pane will open on the left showing the drawings that crashed or were recovered. You do not mention this. Check out how to be sure that is turned on.
MAYBE you will be able to recover the drawing.

BEST HOPE: See if a fellow student or instructor has a super machine with more memory and AutoCAD (in the same or newer file format as your drawing)--- open it on that machine, purge, audit, delete extra and erroneous stuff, etc. If it is still huge, freeze the layers with the giant objects, save. If the layers with the huge objects and (sorry) errors are frozen, the drawing is more likely to open on your machine. Then you can turn on only one complicated layer at a time, and copy what you want to a new drawing.

If you were working closely with your instructor, you should not have been allowed to create a drawing even 25% as large as this, as a student, in my view (unless in Architecture Grad school, maybe)--- you can see now that it is dangerous.

I hope this works for you, or teaches you a bit of how to avoid it next time. If you want to write back with more information, I may be able to help you better, but I have taken 30 minutes of my time to tell you what I can from what you provided.

BOB