Hyper-flexible systems such as ropes, tethers, and wires are simple, light-weight, and deformable, and enable to develop novel soft and dynamic mechanisms. A casting manipulator on the rover will be an application example of the systems. One of its advantage is the manipulator can access behind barricades as craters and enable to pick distance samples. A multi-link system connected by free joints is proposed to be a dynamic model to simulate and analyze dynamic motions of hyper-flexible systems. Large number of links can represent more precise motion but simultaneously more computational costs. On the other hand, it is not always required so many links as to represent simple motions. Therefore it is required to estimate the error of the model from continuous model by the way of discretization. The error of the model is considered by position and orientation error of end-point and shape error. In this paper, these errors are considered and comprehensively estimated about some motions by different number of segmentation.