Optimization of the cutting process on machining time of ankle foot as transtibial prosthesis components using response surface methodology

Abstract

The purpose of this research is to determine the best milling process parameters for minimizing machining time of the ankle-foot as a component of transtibial prostheses. The ankle foot prosthesis is of the energy storing type with Al 6061 material. The experimental design employed the Box Behnken technique, with four factors and three levels for each factor, and machining time as a response. The machining parameters assessed in this study are spindle speed, feed rate, step-over, and toolpath technique. The physical trials were carried out using a three-axis CNC milling machine with a flat endmill cutting tool (diameter 5.5 mm, 2 flute with HSS material). The experiment outcomes were assessed using variance analysis, graphs, and numerical approaches. The response surface method (RSM) calculates the mathematical model of the ideal cutting combination parameters based on machining time. Based on the findings, the ideal cutting parameters in the ankle-foot prosthesis production process on a CNC milling machine were spindle speed of 6500 rpm, feed rate of 800 m/min, step over of 0.2 mm, and flowline toolpath strategy. To establish the machining time value of the ankle-foot prosthesis, the ideal circumstances were identified. The findings of this study revealed that CNC milling gave the quickest time for machining transtibial prosthesis components, which can be used to guide the development of machining methods for ankle-foot prostheses constructed of Al 6061 material. The optimal machining time is 424.4601 min.

Keywords

• Cutting parameters
• Transtibial prosthesis
• CNC milling
• Machining time
• Response surface methodology