Method for machining rotors

A method for machining a compressor blade damper pocket in the dovetail post of a rotor disk of a gas turbine engine having a horizontally split compressor case without removing the rotor from its engine mounting, said machining method comprising:

• mounting the engine in a horizontal position and removing the top inner and outer compressor cases which contain the engines starter blades,
• removing a sufficient number of rotor blades from their respective slots to expose the rotor's blade slot posts which are to have damper pockets machined in and to provide sufficient clearance for the machining process,
• restraining the rotor to prevent rotation during machining,
• masking off the rotor to prevent metal chips from entering the engine,
• positioning a first machining fixture for cutting the pocket by its root in the slot to be machined and clamping it down tight so as to fixture it with respect to the rotor,
• machining away material to form the pocket by guiding a hand held motor powering a machining tool placed in a hollow axle of a guide bushing disposed through a C shaped guide slot in the fixture,
• wherein the machining is done in a series of successive single pass cutting motions wherein the cutting depth of the machining tool is increased for each pass until the desired depth of the pocket is achieved.