Cylindrical =========== A cylindrical joint creates a point that is translated along an axis defined in the reference frame, and a frame that is rotated relative to an existing frame about the same axis. **Keyword Arguments** :param str name: Name given to the joint, default is uppercase characters in alphabetical order (A, B, C, ...) :param str ref_point_key: Start point from which the vector component of the joint is defined :param str ref_frame_key: Reference frame in which the translational and rotational displacement components are defined :param str motion_axis: '+X', '-X', '+Y', '-Y', '+Z', or '-Z', represents the axis in which rotation and translation are defined, **Initial Values** :param numeric initial_t: Initial value in the translational coordinate :param numeric initial_r: Initial value for rotation :param numeric rate_t: Initial speed in the translational coordinate :param numeric rate_r: Initial speed for rotation **Spring Parameters** :param numeric kt: Stiffness in the translational coordinate :param numeric kr: Stiffness for rotation :param numeric ct: Damping in the translational coordinate :param numeric cr: Rotational damping :param numeric equilibrium_t: Equilibrium distance in the translational coordinate :param numeric equilibrium_r: Equilibrium angle