About this 3D model

http://bunkai.sakura.ne.jp/bunkai-wp/3d_printer/572/ PRN3D??????? ???X???????????????????????????????????????????????????????????????????????????????????????????????????????????? ????????????????????????????????????? Is PRN3D exclusive parts. Rigidity against the tension of the belt is a shortage in the X-axis of the pulley standard, it may not maintain the horizontal pulley. By replacing with the edge pulley, to ensure the grounding to the body, to maintain the horizontal even when the belt tension is applied. This prevents the contact of the belt and pulley, to realize the long life of the belt.