@ian_taylor_contractor wrote:
Can you tell me if a dwg / model created using Inventor with multiple ipt / assembly files can be saved / loaded into autocad so that the model can be viewed / walked thru etc
I'm not sure if you meant "dwg" as the literal file extension ".dwg" or not. But in case you did, I wanted to clarify something that I didn't see anyone else mention. In Inventor, the file extension .dwg is only for the actual 2D "paper" drawing. The 3D models are contained in part and assembly files (.ipt and .iam). This is a very different file structure from AutoCAD, where Model Space may contain either 2D or 3D geometry, and then Paper Space layouts are contained on different tabs in the same file (which is a .dwg file). In Inventor, the .dwg would only be the equivalent of the Paper Space layout from AutoCAD, and thus there would be nothing to "walk through".
This is why @CCarreiras was referring to "sheets". If you mention "dwg" to an Inventor user, they typically will assume you are talking about a 2D drawing file, and not a 3D model (unless they are also an AutoCAD user).
It would probably be the highest-level assembly file that you would want to "walk through". There are several options for getting geometry from Inventor to AutoCAD. Some have already been mentioned here. There is one method I would add. @kacper.suchomski mentioned exporting a .igs file and then importing it into AutoCAD. This works, but is usually unnecessary. For many years now, the IMPORT command in AutoCAD has been able to directly import Inventor part and assembly files, so there is typically no need to go through a neutral format like IGS or STEP to get there. This takes your geometry straight from Inventor to AutoCAD without the extra step of the .igs file in the middle.