The Optimization of Surface Quality in Rapid Prototyping

Rapid Prototyping technologies are able of generating physical objects from CAD models. An important aspect of these technologies is the achieved surface quality of manufactured parts. The surface quality is strongly associated with the layered manufacturing. The surface roughness which depends by the staircase effect is a consequence of the layered manufacturing. The staircase effect vary according to the surface slope. This paper presents two different numerical methods to find out the optimal orientation of the 3D model on the working platform of the Rapid Prototyping system, so that the surface regions with higher staircase effect to be as small as possible. The first method, totally automated, find out the angles needed to rotate the 3D model around Ox and Oy axis, so that the number of the triangular facets of the 3D model in stl format, whose slope does not fulfil an initial condition, is minim. The second method involve the user intervention and is based on the visualization with a contrast colour of those triangular facets whose slope does not fulfil an initial condition. Both methods represent valuable tools in rapid prototyping processes. Key-Words: Rapid Prototyping, Optimization, Surface Quality, Staircase Effect, Optimal Orientation