Using catalog data mining in support of determining micro end-milling conditions
A growing number of requirements are being placed on micro fabrication using end mills with high operating degrees-of-freedom. In particular, when the minor diameter of the end mill is 1.0 mm or less, the handling of tools becomes difficult because of the influence of the characteristic size effect and bending of the cutting portion. Furthermore, it is hard for engineers to derive the cutting conditions that can serve as indexes in the early stage of end-milling with small minor diameters. To solve this problem, in this research, on a basis of workpiece material characteristics and tool shape parameters, a system that can make instantaneous decisions on the tool shape and cutting conditions to be used was built, and its usefulness was evaluated. This system was developed by applying data mining techniques together with non-hierarchical and hierarchical clustering methods on tool catalog data. The results of the analysis found that the characteristics of the workpiece material were significant in making decisions regarding the cutting conditions for the minor diameter of the end mill. Moreover, the cutting speed was found to have a significant effect on the tool shape parameters, whereas differences as to the processing method (side milling or slotting) did not have a significant effect.
Basic Study on Micro End-milling
Ultraprecision parts are in high demand in the machinery, electronic, and medical industries. Technologies such as micro-electromechanical systems (MEMS) and ultraprecision machining are used in micromachining to manufacture these parts. The focus of this study is mechanical machining using a micro end mill. In this paper, we experimented with a variety of cutting phenomena that occur during actual machining processes to achieve high machining accuracy, high finished-surface quality, and long tool life. Through examination of these phenomena, micromachining achieved high-accuracy, high-grade machining by considering the dynamic vibrational behavior and elastic contact of the tools. In addition, we suggest criteria for determining the tool life of a micro end-mill.
Development of ultra-precision machining system with unique wire EDM tool fabrication system for micro/nano-machining
Aiming at quality machining of very hard materials with nanometer level surface quality and 0.1 μm dimensional accuracy, an ultra-precision machining system has been developed. The machine has feed axes accompanied by the counter motion mechanism driven at the center of gravity to eliminate the vibration caused by high acceleration/deceleration. A custom tool fabrication system consists of a 6-axis wire EDM machine and dedicated custom tool CAM system. High quality machining of sophisticated three-dimensional (3D) products made of tungsten carbide has successfully been demonstrated on the developed machine tool with custom-made PCD cutters fabricated by the tool fabrication system.