System and method for machining a slot in an inner surface of a casing for a gas turbine engine

A milling device for machining a slot into an inner surface of a casing for a gas turbine engine, comprising:

• a frame assembly comprising a plurality of structural guides configured to engage structural features on the inner surface of the casing to maintain an axial position of the milling device relative to a longitudinal axis of the casing;
• and
• a milling cutter coupled to the frame assembly;
• and
• wherein the milling device is configured to be displaced in a circumferential direction relative to the longitudinal axis to machine the slot, via the milling cutter, along the inner surface of the casing in the circumferential direction,
• wherein the frame assembly is adjustable in both an axial direction and a radial direction relative to the longitudinal axis of the casing, the axial direction extending parallel to the longitudinal axis of the casing, and the radial direction extending radially from the axial direction;
• wherein the frame assembly further comprises a plate oriented in the radial direction, a pair of support brackets coupled to the plate, and a pair of support arms coupled to the plate via the pair of support brackets, and both the pair of support brackets and the pair of support arms extend away from the plate, wherein the milling cutter is coupled to the plate, and wherein both the pair of support brackets and the pair of support arms flank the plate;
• wherein a width between the pair of support arms in the axial direction is configured to be adjusted via adjusting respective positions of the pair of support brackets;
• wherein the frame assembly further comprises a plurality of support structures that are adjustable in the radial direction relative to the pair of support brackets,
• wherein each of the plurality of support structures comprises a respective stem portion and a respective end portion, and each of the plurality of structural guides being coupled to a respective one of the plurality of support structures;
• and
• wherein each of the plurality of support structures is coupled to a respective one of the pair of support brackets such the stem portion of each of the plurality of support structures is configured to move in the radial direction within a respective recess of the respective one of the pair of support brackets.