Method and apparatus for in situ extension of wind turbine blades

A combination of a rail-guided milling tool and a tool positioning fixture, the combination comprising:

• the rail-guided milling tool, which rail-guided milling tool comprises:
• at least one cutting wheel comprising a camber, the at least one cutting wheel being configured to remove material from a surface of an installed blade of a wind turbine to form the surface in the shape of the camber;
• a working arm configured to press the at least one cutting wheel towards the surface of the blade of the wind turbine;
• a pivoting rod pivotably connected to the working arm;
• a frame having at least one frame rail;
• a table supporting the pivoting rod, the table configured to slide along the at least one frame rail of the frame;
• the combination further comprising:
• the tool positioning fixture, which tool positioning fixture is configured to support the frame and position the rail-guided milling tool along the blade of the wind turbine at a precise position for facilitating removal of a respective identical portion of a respective tip of each blade of a plurality of blades of the wind turbine, the tool positioning fixture comprising:
• a tip reference plate configured to provide a reference for positioning the tool positioning fixture relative to the originally installed blade tip;
• at least one tip distancing bar affixed to and extending from the tip reference plate;
• a first base alignment bar attached to the at least one tip distancing bar;
• at least one trailing edge alignment bar affixed to the first base alignment bar and extending in parallel to the at least one tip distancing bar;
• at least one leading edge alignment bar affixed to the first base alignment bar and extending in parallel to the at least one tip distancing bar;
• a second base alignment bar attached to the at least one trailing edge alignment bar and positioned in parallel to the first base alignment bar;
• and
• wherein the tool positioning fixture provides for precise positioning of the rail-guided milling tool at the same location on each blade of the plurality of blades of the wind turbine;
• and
• wherein the working arm is configured to press the at least one cutting wheel towards the surface and move the sliding table and the at least one cutting wheel along the at least one frame rail of the frame to remove material from the surface of the blade of the wind turbine being machined, in order to form the surface in the shape of the camber of the at least one cutting wheel.