Artcam File Converter !!hot!! Link
You can convert external 3D meshes into ArtCAM reliefs. Supported formats include STL, OBJ, 3D DXF, and 3DS Exporting from ArtCAM to STL:
Since ArtCAM is no longer officially supported, many users "convert" their workflow to newer software that can open legacy ArtCAM files or provide similar tools: artcam file converter