To develop a hand rehabilitation device, the patient-specific heterogeneity of physical ailments must be considered in the design process to provide optimized rehabilitation. In this paper, we suggest a low-cost customized manufacturing process of a hand rehabilitation system. We first extract the length and size of the fingers based on a CMOS camera system. Then, the mechanical components of the rehabilitation system were manufactured using a 3D printer. User safety is guaranteed using a simple operation range control connector mechanism which mechanically locks up when the range of motion of each finger is exceeded for finger extension. We verified the usability of the hand rehabilitation system and applied the system to two custom interactive video games.