Fused deposition modeling (FDM) is a filament based rapid prototyping system provides us to manufacture real parts with multiple production-grade materials, such as ABS-M30, PC, PPSF and PC-ABS blend. Fused deposition modeling technology, essentially perform using layer manufacturing process. More complex 3D physical models can be efficiently fabricated without geometric limitation by this technology; a remarkable reduction in production life cycle has been achieved. However, due to the Layer Manufacturing process, stair case effect is unavoidable which results in poor surface finish. In this paper, the surface roughness of a model having surfaces at different angles produced by fused deposition modelling machine is analyzed to understand the effect of different angled surfaces on the surface roughness of the model of FDM produced part model. پرونده مقاله