Different CNC machining condition of paulownia wood by CNC; Influence on the abbott roughness parameters

The aim of this study was to investigate the factors affecting surface quality of paulownia wood during milling by advanced computer numerical control (CNC) machine. For this aim wood logs converted to proper sizes (2.5 x 10 x 15 cm) and then air dried. The variable of this study were spindle speed of machine (10000 and 18000 rpm), feeding rate (6 and 12 m/min), cutting depth (1and 5 mm), cutting method (down and up-milling) and cutting pattern (tangential and radial). Roughness of cut specimens edge were evaluated by profilometer method according to ISO 13565 standard. For evaluation of surface quality Abbott group parameters (Rpk, Rk, Rvk) were used. Degree of effective of the parameters was evaluated by fractional factorial design as completely random design at confidence level of 95%. The result showed that spindle speed, cutting method and feed rate are influencing factors on surface quality of milled specimens and their effect was significant. With increasing spindle speed and decreasing feeding rate the roughness decreased and surface quality improved. In up-milling cutting method, degree of roughness was higher and consequently surface quality was inferior. Cutting method in comparison to other factors had the high influence on surface quality. The rest variable did not have independent influence on surface quality at 95% confidence level.