A modular surgical robot design is presented in this paper. The focus is on making the robot more flexible and reconfigurable, while ensuring human-safe robot interactions. The cable-driven robot has modular link and joint designs, enabling a variety of serial configurations. The joint design includes a biasing spring which inherently creates a maximum load threshold while also reducing the number of actuating cables by half. Safety of this joint mechanism is ensured by a ratchet-based locking mechanism. Design and analysis of this robot are presented.