aha...thank you. Wiki <https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_OpenSCAD_in_a_command_line_environment#Export_options> > For at least 2015.03-2+, specifying the extension .echo causes openscad to > produce a text file containing error messages and the output of all echo() > calls in filename as they would appear in the console window visible in > the GUI. Multiple output files are not supported, so using this option you > cannot also obtain the model that would have normally been generated. > Multiple output files are not supported -- Sent from: http://forum.openscad.org/