This part is an IGES file that is included in the SolidWorks 2007 Sheet Metal Training Manual as one of the examples on how to convert an imported (dumb) part to sheet metal. According to the explanations in the manual, this can be done as a two step process, by first using the Rip feature to select edges or corners that will be cut with a small gap in order to allow the part to be flattened as...