The aim of this thesis was to investigate if the robotized welding method FSW (Friction Stir Welding) could be applied for joining a rotating structure in an aero engine at Volvo Aero Corporation. FSW is expected to introduce less defects than today’s welding methods and could therefore be suitable for critical aero components. The material is the nickel based alloy Inconel 718, however a material experimentation is outside the scope of this report.The main goal of this study is to verify if the ESAB ROSIO robot based FSW-system has a suitable work space to be able to weld the rotating structure, and if the welding tool has accessibility to the joints. The FSW-process needs a rigid fixture, and a number of fix-ture concepts are presented based on a proposed weld sequence. A final fixture design is proposed, which requires a new design of the structure.The accessibility studies were performed in the robot simulations software Robot Stu-dio. This showed that the robot was unable to weld the proposed model in all areas in the original design. If the robot and the rotating structure can be redesigned the access will be achieved as shown in Robot Studio simulations.In order to be implemented in real production a number of further actions need to be taken and the result of this study can be a basis for these.