You can also try to import files in the DXF format in the free SU version using this plugin: http://sketchucation.com/forums/viewtopic.php?f=323&t=22199&hilit=dwg+importer#p186621 And use it the same way you'd use dwg. dxf and dwg are common CAD file formats based on AutoCAD, but often available for exporting from other CAD packages.