Conversion from mathcad to STL is not supported yet :(

Mathcad is computer software primarily intended for the verification, validation, documentation and re-use of engineering calculations. It is used by engineers and scientists in various disciplines – most often those of mechanical, chemical, electrical, and civil engineering.

Mathcad is part of a broader product development system developed by PTC, and often utilized for the many analytical touch points within the systems engineering processes. It integrates with PTC’s other solutions that aid product development, including Creo Elements/Pro, Windchill, and Creo Elements/View. Its live feature-level integration with Creo Elements/Pro enables Mathcad analytical models to be directly used in driving CAD geometry.

STL (STereoLithography) is a file format native to the stereolithography CAD software. This file format is supported by many other software packages; it is widely used for rapid prototyping, 3D printing and computer-aided manufacturing. STL files describe only the surface geometry of a three-dimensional object without any representation of color, texture or other common CAD model attributes. The STL format specifies both ASCII and binary representations. Binary files are more common, since they are more compact.