Effect of Machining Parameters On the Surface Roughness of Dolomite Cups

Natural Stones product from Indonesia frequently used as product of pottery and medical devices. However, characteristics variation and hardness divergence level of natural stone (dolomite) causes differences in the requirements of machine parameters on the manufacturing of it. Especially for the process of cylindrical shape of dolomite cups. The machinery parameters of dolomite that baffle. Consequently, the process of dolomite cups manufactures becomes not optimal and need to investigate about the effect of machining parameters to the process of dolomite cups, so that the surface of the dolomite cups products can be smoother to the maximum to reduce finishing time. The first step to investigate in this research is to test the material characteristics and hardness test on dolomite cups originating from Malang Regency, Indonesia. Based on the data of hardness and characteristic test, generated the value of cutting speed, Feed and deep of cut with 3 different parameter levels. The result of the machining process is further tested by surface roughness measurement, which then obtained the results of surface roughness values of each level parameter. From the data collected could be generated that the value of cutting speed is directly proportional to the level of surface roughness, on the other hand for feed and deep of cut inversely proportional to the level of surface roughness of the dolomite cups turning process. It can be concluded that to get the result of surface of workpiece of dolomite cups with low surface roughness can be done by choosing high cutting speed, while feed and deep of cut chosen as small as possible. By the data gaining from the research found that the optimal parameter which result of the smoothest surface occurs in the 900m/ min cutting speed, 0,06mm/ rev feed and 0,1mm deep of cut.