NX software from Siemens PLM (formerly USG), supports STL output at the core level, enabling you to save not only entire parts as STL files, but also selected surfaces of a part. This gives you great flexibility when preparing objects for 3D printing. In addition, assembly output enables you to save several components as a single unit while maintaining each component as a separate volume (shell).
forward File > Export > STL
forward Rapid Prototyping dialogue box will appear
forward Output Type: Binary
Binary STL files are much smaller than STL files saved in ASCII format
forward Triangle Tolerance: 0.015 mm
This is the maximum distance allowed between the surface of the original design and the tessellated surface of the STL triangle, and affects the smoothness of the model surface
forward Adjacency Tolerance: 0.015 mm
This determines if two adjacent surfaces “attach”. If the distance between the two surfaces is less than this setting, they are considered attached. This setting must be less than the printing resolution. For example, when printing models at a resolution of 30 micrometers (microns), the setting must be no more than 0.03 mm.
forward Auto Normal Gen: Check box
forward Normal Display: Check box
forward Triangle Display: Check box
forward Click OK
forward Export Rapid Prototyping dialogue box will appear