Harvesting CAD Details - Best Practice?

[Jazzster11]

Okay, so I've read plenty of threads here and I've read Autodesk's Technical Bulletin on Revit 2010 file performance, so I believe that importing DWGs and exploding them will most likely destroy the universe (or atleast our files.)  I even tried a little experiment with a clean Revit project file and watching the file size inflate as I imported a DWG, and then exploded it.  I also tried exploding it in a separate file, grouping the information, and THEN pasting the group into my test file, and the least file growth was caused by simply importing a DWG (which doesn't give us much flexibility when we need to edit it.)

So, are all you experts out there really importing/linking into separate files and placing detail lines/model lines/walls/etc. over the imported/linked components?  There's a wealth of DWGs on manufacturer's websites that we use to plug into our details, but how can we work with their DWG's without killing our file sizes?

Are there any improvements to RAC 2011 that affect how users are working with imported content?

Thanks.

- Alex

[Jazzster11]

(here are Autodesk's recommendations for DWG imports:  http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=8891637&linkID=9243099)

This doesn't go into as much specificity as I was hoping for.

- Alex

[jbc]

I try and avoid importing CAD files where possible. I link CAD files that I need as a guide to create floor plans etc and then unload them. If I need to import a CAD file and then use that CAD data I try to do this by creating a separate REVIT family first, by importing the cleaned up CAD file as described below and then import the REVIT Family.

If you are talking about CAD details only and importing them directly into your REVIT project. I clean up the CAD file first by making each detail a separate file, explode all elements, put all lines on layer 0, purge, set 0,0 origin to an obvious location, delete all dimensions, leaders and hatching.

I redefine the text to the appropriate REVIT text style. I attach new leaders to the text in REVIT and redimension in REVIT and add new hatching in REVIT.

I then change all the lines on layer 0 to the appropriate REVIT linestyles as required for the graphics in the detail. 

We have years of CAD details that we are changing to REVIT using the methods above as required on a job by job basis. Also its a good exercise for the juniors in the office who are just starting up with REVIT.

This may seem to be a lot of work but you then get a clean REVIT detail using the existing CAD data and it will help keep your REVIT files a lot cleaner and smaller.

gjettner