Opening CAD without CAD

March 20, 2006 8:46 AM

Does anyone know any good freeware that will allow me to open and/or preview CAD (specifically .dwg codec) files?

I've been contracted to do a large mural for a fitness center. The files they sent are in a .dwg format. I recognize this to be a CAD codec but do not own any CAD software and my Illustrator (version 10), which has the module to open it, crashes each time I try it (that, being a whole other problem). CAD files don't appear huge (5 megs). I just need to be able to view them and perhaps export them as an image, not manipulate them. I'm running Mac OS 10.3.9. Any help would be appreciated.

Crazy thing, I did find this old, open source Military CAD program (BRL-CAD). They had a version for OSX which I installed and strangely, after it says it successfully installed, it is nowhere to be found on my hard drive. Re-installed, same thing, it's not anywhere. And this seemed like software that would have worked. Oh well.....

posted by j.p. Hung to computers & internet (6 comments total)

How about a .dwf viewer?

Here
posted by askmatrix at 8:59 AM on March 20, 2006

The viewer is for a PC download only. Thanks anyway!
posted by j.p. Hung at 9:10 AM on March 20, 2006

Just saw one yesterday here.
posted by kimota at 9:20 AM on March 20, 2006

I don't know if it opends .dwg files (no time to look at the moment) but you might look into the free viewer version of SketchUp. Also try Vectorworks Viewer. Other CAD programs might crack DWG files with free viewers but I don't think that AutoCAD (DWG is their format, DXF is generic) has any Mac support at all anymore. If all esle fails, I can open DWG files and export into a few formats -- no guarantee but I might be able to help. Email in profile.
posted by Dick Paris at 9:28 AM on March 20, 2006

Thanks a lot for the help, the e-drawings did what I needed, allowed me to view it. Thanks again!!
posted by j.p. Hung at 9:50 AM on March 20, 2006

It looks like you got this resolved, so I guess this is just an FY(Future)I:

5 MB is pretty big for a DWG, and large DWG files usually have a number of errors in them. AutoCAD is usually pretty good about gracefully ignoring the errors (but it won't fix them unless you tell it to), but Illustrator much less so.

Also, due to the way AutoCAD manages lineweights (it uses a separate file to map line colors to "pen" weights), opening a DWG in Illustrator usually means that you lose all lineweight information.

My typical workflow for going from DWG to Illustrator or the like is to print to a PDF driver -- this corrects the scaling (DWGs are typically drawn "full-scale" -- 1 inch equals 1 inch) and lineweight issues)
posted by misterbrandt at 1:00 PM on March 20, 2006