Multi Response Optimization of Turning Parameter Power Screw Hospital Bed Using Taguchi-Hybrid Method

Abstract

Power screw is the driving part of a hospital bed which functions to raise and lower the bed. Power screw is an important part of hospital bed products that requires precision and accuracy, then in the manufacturing process by using CNC Turning machine with steady rest. Based on the observations, the defect of power screw caused by worn out tools. It causes chatter on CNC Turning machine. The aim of this study is to reduce the variation of power screw product by conducting experiments in the manufacturing process of power screw. The experiment was done by determining some factors such as spindle speed, depth of cut, coolant and usage time of tool. The specific purpose of this experiment is to reduce variation and simultance optimize are major diameter, minor diameter, pitch diameter, and cycle time. Taguchi multi response method was used for experiment to get simultance optimize process. Multi response case was done by using Grey Relational Analysis (GRA) and Principal Component Analysis (PCA). Experiment based on the orthogonal array of L9 with 3 replications. The results show that by using Taguchi-hybrid method, the optimum condition occurred at spindle speed is 1200 mm/min, depth of cut is 0.1 mm, coolant is 1:30, and usage time of tool is 70%. The result of the experiments carried out showed a decrease in the response variance in diameter and the cycle time faster.