Expression for Surface Roughness Distribution of FDM Processed Parts

Rapid prototyping (RP) processed parts are mainly fabricated by layered manufacturing process. Hence stair steps occur at surface of the part and affect the quality of the surface. Also, the surface roughness by the stair step depends on surface angle. Therefore, prediction of the surface roughness distribution by the change of surface angle for a part to be processed is required on the process planning stage of the RP. This paper proposes a methodology to express surface roughness distribution of the part which is processed by the FDM. In order to reflect actual roughness distribution in computing, a surface roughness distribution equation is presented based on interpolation using measured roughness values. And, the computing accuracy by the number of the measured roughness data is analyzed. The implemented results show that the proposed methodology can be practical.