My PowerSpec Ultra 3D printer came with PowerPrint software. The software expected 3D models to use metric measurement system (mm) instead of Imperial measurement system (inches). I tried to use AutoCAD to create a 3D model but AutoCAD can't export 3D models to STL files using correct measurement system. If the 3D model was created using Imperial measurement system and exported to STL file, PowerPrint gets confused and thinks that 8 inches is 8 mm! How can I fix the problem?