A robotic apparatus for machining tenons on turbine buckets of a steam turbine machine is disclosed. The robotic apparatus includes a machining device having a spindle head. A robotic arm is coupled to the machining device and a base member is coupled to the robotic arm. The base member is mounted independently of the machine element. A vision system is provided for locating the tenon on the turbine bucket. A control system is coupled to the vision system, the machining device and the robotic apparatus. The control system is configured to control movement of the robotic apparatus and the machining device based upon vision system data and spatial information about the tenon and the turbine bucket.