Development of a cost-effective high-precision bench machine tool for multi-level micro aspheric lighting-lens mold machining

This study presents the development of a cost-effective high-precision bench machine tool prototype for machining multi-level micro aspheric lighting-lens molds. To achieve high-precision over a long lifetime of micromachining, the bench machine tool is designed using a small C-shaped framework to strengthen static rigidity and vibration resistance. The primary structures of the machine tool are constructed with tempered nodular graphite cast iron to obtain a high damping coefficient and high inherent resonant frequency. A multi-level aspheric curve generator is designed according to the multi-level aspheric curve equation to easily create an aspheric curve and then rotated into an aspheric surface form with a symmetrical optical axis. The verifications of the designed bench machine tool's functions were conducted by machining the micro aspheric lighting-lens molds using high-speed micro milling. Experimental results demonstrate that form accuracy and surface roughness for the micro aspheric lightinglens mold of Rt 2. 937 μm and Ra equal to 0. 032 μm respectively could be simultaneously achieved. The developed cost-effective bench machine tool can supply high-quality and fast machining in the fabrication of micro optoelectronic molds such as those used for micro aspheric lighting-lenses.