TORCH END-EFFECTOR AND TIG ELECTRODE CHANGEOUT DESIGN FOR A TIG WELDING ROBOT USED IN METAL BIG AREA ADDITIVE MANUFACTURING

Metal Big Area Additive Manufacturing (mBAAM) is a promising approach to large-scale metal additive manufacturing (AM) or 3D printing. The mBAAM system uses an arc-based wire-fed welding robot to build metal parts. A multi-degree-of freedom robotic arm is known for its extensive range of motion and reliable tool handling. Attaching a torch end-effector to a robotic arm gives it welding capabilities; however, this decreases the motion range and dynamics of the robot. As a result, build volume and printing accuracy are decreased. Additionally, only a portion of time is spent printing in an arc based process. Maintenance leads to downtime on the system. In a tungsten inert gas (TIG)-based process, the torch electrode wears out over time and must be changed to avoid defective deposition. This paper proposes an approach for a compact torch end-effector to improve the robot's build volume. This paper also proposes an approach to reducing non-printing process time by designing and implementing a semi-automated electrode changing system.