Abstract: A method and apparatus for wire cutting electric discharge machining to achieve precise surfaces with Ra<0.1 microns. An intermittent operation is used with erosion pulses for primarily machining and erosion pulses for measuring any excursion of the wire electrode from the rest position. An evaluation unit is used to determine any excursions of the wire electrode from the rest position that might have been present during the preceding machining time, and a controller controls the machining process so that the wire electrode is practically straight during electroerosion.

Abstract: EDM according to the present invention involves an intermttent type of operation between erosion pulses and measurement pulses in order to circumvent an interfering self-control effect of an electrode during fine machining. To achieve shorter processing times, higher precision and better reproducibility, the method and apparatus determine with an electrical measurement the amount that an electrode is in contact with a workpiece during a measurement time that erosion has been interrupted. A pulse duty factor is then obtained from the contact amount to control further processing via, for example, the duration of the erosion pulses.

Abstract: A method of precision electric-discharge machining carried out in apparatus of moderately high precision and stability with an electrode in the form of a wire. The object is a surface as smooth as the surface that can be obtained with the more expensive very high-precision apparatus. The contour of work that has already been roughed out at least once is accordingly exploited as a geometrical reference for at least one finishing cut. The gap is maintained constant by fine adjustments.

Abstract: A method for the initial cutting of a workpiece by electrical discharge cutting by a wire electrode, in which the values for the specific cutting parameters are reduced along an introduction path in the workpiece at least in part as compared with the values of the cutting parameters for the actual cutting contour, and at least some of the reduced values of the cutting parameters are continuously changed until the values intended for the actual cutting contour are reached.