Is there a simple way to convert .stl files to .dwg format.
Converting Stereolithography Files directly to AutoCAD Drawings (.stl to .dwg conversion) is certainly possible, and should be quite straightforward using any of the numerous available 3D modeling/CAD programs that support the .stl format, such as SolidWorks, TurboCAD or CATIA.
Please keep in mind that some programs only generate 2D views of 3D models, so select your program accordingly.