This paper addresses the optimal design of a new parallel robot, the Expteron, in which a networked scissor used as linear joint allows to reduce the swept volume of the kinematics chains. This robot is based on the Tripteron robot where the passive elbows constituted by two bars and three revolute joints are replaced by a set of networked scissors. By changing the architecture of the leg, only one working mode stands for each leg. The design is conducted on the basis of one prescribed cubic Cartesian workspace. The number of loops in the networked scissors are computed to avoid self-interference and to reduce the swept volume. A finite element analysis is made to define a preliminary stiffness model to predict the bending deformation when the mobile platform are subjected to unidirectional forces along the z-axis.