Conversion from Navisworks to IAM is not supported yet :(

Navisworks is a native file of Navisworks® project review software by Autodesk.

Navisworks files come in three formats: NWD, NWF, and NWC. An NWD is a single file that contains all model geometry, environment, viewpoints, and review markups. An NWF file is a list of links to the original files. It doesn't keep model geometry and, to be opened, requires access to the original CAD files. An NWC is a cache file created from any native CAD or laser scan files, when opened in Navisworks.

An IAM file is an assembly model created with Inventor CAD and engineering software by Autodesk.

The IAM format comprises parts and subassemblies linked through assembly relationships. A subassembly in an IAM file is a self-contained unit with its collection of parts.

The .iam extension of an Autodesk Inventor Assembly Data File can be viewed using the following software: Autodesk Inventor / Inventor View, and Spaceclaim Engineer software. Autodesk Viewer web application and Fusion 360 integrated CAD / CAM / CAE software environment can import and render an assembly model created with Inventor.