About this 3D model

http://bunkai.sakura.ne.jp/bunkai-wp/3d_printer/600/ PRN3D??????? ??????????????????????? ???????????????????????????????????? ??????????????M3?????????????????????????????? Is PRN3D exclusive parts. It is a part of correcting the deflection of the heat head base. Is multiplied by the tension of the stronger parts of the linear bush outside, leading to a proper shape. Also, by embedding the M3 nut to nut hole of the front part, it can also be used in future enhancements.