Mid Sweden University

3D printing a CAD modelnormally requires conversion into a polygon mesh, usually an STL-file, in orderto be able to load the model in the slicer. This conversion destroys roundsurfaces and replaces them with flat surfaces. Slicing a polygon mesh resultsin one or more polygons, consisting of a number of straight lines. This canaffect both dimensional accuracy and surface smoothness. Modern 3D-printerscan, in addition to straight lines, handle arcs. However, today’s commonslicers can not generate arcs as the input does not contain any curvedfeatures. This project aims at finding an alternative solution. By directslicing of CAD models the slices can contain arcs, and the slicer can producearc commands for the 3D-printer. During this project a prototype slicer isconstructed as a proof of concept. The prototype handles STEP-files as inputand creates both linear and circular movement for the 3D-printer. The resultsshow that both the intermediate files (STEP/STL) and the resulting G-code filescan get smaller, yet preserving the original shape, by using this method. Theproposed solution has a positive effect on the 3D-printing workflow as well, asthe intermediate files can be imported back into the CAD system. The projectconcludes that there is possibly a bright future for direct slicing, but thereare more problems to solve before it can become reality.