LAUSR

Parallel manipulator robots are widely used in a large number of applications because they provide important advantages in terms of superior speeds and accelerations, high stiffness and good dynamic performance. In additive manufacturing (AM), this kind of kinematic structures is being increasingly explored to develop new curved and multi-directional fabrication strategies. Based on this application, this work presents the design and dimensional synthesis of a new structure of the Linear Delta parallel robot for AM (3D printing). The new structure uses an innovative concept of Delta mechanism with single legs and rotational joints, which consists of twelve links (three parallel single legs), three prismatic joints and eleven revolute joints. A particular feature of the proposed mechanism is that it contains a joint common to all the kinematic chains instead of a mobile platform as in the conventional Linear Delta structures. Mobility analysis, inverse and direct kinematics, and a study of dimensional synthesis are described in detail. A method of efficient optimization based on genetic algorithms is used to find the minimum dimensional parameters of the robot, considering the maximization of the useful workspace as the main performance index. In order to validate the proposal, a prototype of the robot was built. Capability and geometric deviations analysis was carried out for three test parts resulting in a 0.3-mm deviation/error within a confidence interval of 99.7%.