Abstract: An electrical discharge machining (EDM) apparatus includes at least one work station having an electrode fixedly mounted to a base and a workpiece fixture slidingly mounted to the base above the electrode. A servomotor is mounted to the base and arranged to drive the workpiece fixture toward and away from the workpiece. Preferably, the EDM apparatus will include a number of such work stations, and each work station will be connected to a separate control system for independently controlling and energizing the work station.

Abstract: A device for machining a cylindrically shaped gas turbine engine component includes a computer numerical controlled lathe and a wheel-shaped electrode for spark erosion machining of the component. The lathe includes a faceplate for mounting and rotating the component, and a gage surface is concentrically mounted relative to the component on the faceplate for in-process determination of a largest gaged radius of the wheel-shaped electrode. The radius is determined by the computer numerical control when an electronic current sensing circuit signals the computer numerical control that the electrode has contacted the gage surface. The electrode can then be positioned relative to the component, to correct for erosion of material from the electrode caused by the previous machining cycle, before a subsequent machining cycle.