It seems there is several options how to perform COB to STL conversion. Both are 3D/CAD file types so you should have no trouble with converting Caligari 3D object files (*.cob) as Stereolithography files (*.stl). For example Accutrans 3D or CopperCube can probably make this conversion happen.
Convert Caligari trueSpace 3D object file to Stereolithography CAD file.
We have found 3 software records in our database eligible for .cob to .stl file format conversion.
Microsoft Windows software - convert cob to stl on Windows
AccuTrans 3D provides accurate translation of 3D geometry between the file formats used by many popular modeling programs. Positional and rotational information for the 3D meshes is maintained.
Convert from cob file
to stl file
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned cob to stl. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A software suite used for 3D CAD/DCC + Animation/Model/NURBS/Skinning translation, optimization and viewing.
On-line services software - convert cob to stl on web
Online 3D Model Converter is a free tool used to convert 3D models from one file format to another