Ok, I had a friend who is good with 3DS max make a model that he wants created in inventor so I can create parts and panels for it.  However, I have not been able to import from 3DSMax to Inventor.  I have managed to get the model out of 3DSMax to AutoCAD, and it is currently in AutoCAD as a wireframe 3D model.  I have still not managed to get it into Inventor.  I have tried exporting it out of 3DSMax as a .3ds file, no dice.I have tried exporting it out of AutoCAD as a .dxf file, still nothing.I have tried importing it as an object from both 3DS and AutoCAD, nothing.Any ideas?

Depending on the version of 3ds Max you can also use the ACIS SAT export (part of the "3dsmax 2010 Connection Extension"). It directly exports solid models (not just surface models) for AutoCAD, Inventor or Revit.

does that "3dsmax 2010 connection Extension" come standard with the 3dsmax 2010? or is that an additional component that I need to download?

No, it is a separate component (will be probably included in standard 3ds Max 2011).

and where can I get this secondary extension?  and how much does it cost?[EDIT]  Nevermind, I found it.  It is part of 3DSMax Design 2010, and comes standard with that software package.  There are two seperate software packages: 3DSMax 2010, and 3DSMax Design 2010.  So thank you for your help as to which extension I needed.  I will update as to how well it worked.
StarSerenade2009-12-12 00:48:07