The study of proper conditions in face Coconut wood by CNC milling machine

The purpose of this research is to investigate the effect of main factors on the surface roughness (R_a) in Coconut wood facing process by Computer Numerical Controlled milling machine and using shell end mill cutting tools. The main factors, namely, cutting speed, feed rate, depth of cut and angle of cut were investigated for optimum surface roughness. Normally, acceptable surface roughness was between 3.0-0.9 μm for this before sanding process. In the experiment, Coconut wood of 11-13% humidity was use at 1000-2000 rpm in cutting speed and feed rate at 100-300 mm./min and the result of preliminary trial shown that depth of cut and angle of cut had no effect on surface roughness. It was found from the experiment that the factor affecting surface roughness was feed rate and cutting speed, with tendency for reduction of roughness value at lower feed rate and greater cutting speed. Therefore, in the facing Coconut wood it was possible determine a facing condition by means of the equation Ra = 4.72 - 0.000864 Speed + 0.00443 Feed Leading this equation goes to use is in limitation cutting speed 1000-2000 rpm at feed rate 100-300 mm/min. The result from the experiment of mean absolute percentage error (MEPE) of the equation of surface roughness is 4.64% which is less than the margin of error, and is acceptable. As a result, the selection of optimal machining parameters can be greatly benefited to the Coconut wood furniture manufacturing industry in terms of productivity improvement.