With the advent of high-tech products, the need for ultra-precision machining has become increasingly necessary, along with the need for a jig center machining center capable of precision machining. A jig center maintains the accuracy of a jig borer, and also has an automatic tool changer like that of a machining center. It performs various machining functions in addition to hole machining and is the most precise and rigid machine tool. Various control methods and analytical techniques to improve machining accuracy are currently being developed in the field of ultra-precise large-scale machine tools. One relevant finding is that the degree of deformation varies depending on the weight of the machine tool as well as the ground conditions. It is therefore necessary to optimize ground conditions before installing the machine tools so as to improve the machining accuracy. The depth of concrete as well as the depth and diameter of grout were selected as variables. We developed the simulation case through structural analysis to consider the position of columns and tables. As a result of optimizing the foundation condition, it was found that the relative displacement error was reduced by up to 98% compared to the rigid foundation condition.

The recent crisis of environmental pollution and resource depletion has become a major global issue, resulting in an increasing interest in remanufacturing in many countries. However, manufacturing for environmental protection is considered an additional cost factor by most companies. Therefore, governments worldwide have actively implemented remanufacturing policies to encourage the participation of numerous companies in the remanufacturing industry. As an eco-friendly technology, remanufacturing has impacted the environmental improvement and resource savings by reducing raw materials and production processes. In particular, the effect of machine tool and automobile part remanufacturing is very remarkable, since most parts are reusable. In this study, the standardization technology for remanufacturing process of machine tools is developed by remanufacturing of used vertical machining center. Based on the work operation sheet for establishing the process, the remanufacturing process chart and program were developed. The performance evaluation of machining centers before and after remanufacturing was also executed, to check the performance improvement of the remanufactured product. The performance evaluation criteria were established to improve reliability.