The 6-RKS (or 6-RUS) parallel manipulator is a spatial mechanism consisting of two platforms, one fixed and the other mobile, with 6 degrees of freedom, joined by 6 kinematic chains of type RKS, where R stands for a revolute joint, K for a cardan joint and S for a spherical joint. The model image was built by Isidro Zabalza in the laboratories of the Public University of Navarra.