Conversion from Powermill to FreeCAD is not supported yet :(

Powermill is a 3D Computer-aided manufacturing app developed by Autodesk Inc. It runs on Microsoft Windows and is used in many different engineering industries to determine optimal toolpaths to reduce time and manufacturing costs.

Powermill rapidly creates toolpaths on large, complex parts, works with surfaces, solids and STL meshes. It uses efficient roughing strategies and can create gouge and collision free toolpaths, which can be edited and optimized. The software obtains comprehensive range of finishing toolpaths, user-defined macros and templates for automated CAM, extensive library of tool types for use with 3- and 5-axis milling, and specialist tools for demanding industries and applications.

FreeCAD is a customizable, open-source paramentic 3D CAD and BIM software with FEM support, built on the Opencascade geometric kernel. It was created primarily for product design and mechanical engineering, but it can be used in a wide range of industries, such as electrical engineering, or architecture. It runs on Windows, Mac OS, and Linux.

FreeCAD is made to craft real-life objects of different sizes and is perfect for a home user/amateur, programmer, experienced CAD software user, or educator. This software provides tools similar to those of SolidWorks, Catia or Autodesk Revit.