THE EFFECTS OF SPINDLE SPEED AND FEED RATE ON HOLE QUALITY IN DRILLING OPERATION: THE TAGUCHI BASED DESIGN OF EXPERIMENT

In manufacturing, the quality of holes produced is very important. For instance, the hole size may determine the ability of two parts to be assembled. At the same time, the hole surface may also contribute to the ease in assembly process. However, the quality of holes produced in drilling operation is affected by drilling parameters such as the drill speed and feed rate. Therefore, it is necessary to determine the suitable drilling parameters’ setting such that optimum hole quality can be achieved. This project aimed to determine the effect of drill speeds and feed rates on material surface roughness and radius accuracy. The experiment was designed based on the Taguchi method. The drilling operation was conducted using Okuma CNC milling machine on mild steel plate with different settings of spindle speeds and feed rates. The experimental results showed that the spindle speed affects significantly the surface roughness and radius accuracy. Whereas, the feed rate is only affect significantly the surface roughness. Besides, it is found that the optimum spindle speed and feed rate are 500 rpm and 150 mm/min to produce the minimum surface roughness. At the same time, the analysis also shown that the optimum spindle speed and feed rate to produce maximum radius accuracy are at 2000 rpm and 150 mm/min.