This paper deals with the kinematics and dynamics of a two degree of freedom
spherical manipulator, the wrist of Orthoglide 5-axis. The latter is a parallel
kinematics machine composed of two manipulators: i) the Orthoglide 3-axis; a
three-dof translational parallel manipulator that belongs to the family of
Delta robots, and ii) the Agile eye; a two-dof parallel spherical wrist. The
geometric and inertial parameters used in the model are determined by means of
a CAD software. The performance of the spherical wrist is emphasized by means
of several test trajectories. The effects of machining and/or cutting forces
and the length of the cutting tool on the dynamic performance of the wrist are
also analyzed. Finally, a preliminary selection of the motors is proposed from
the velocities and torques required by the actuators to carry out the test
trajectories
