Monitoring breakthrough of electrical discharge machining electrode through a workpiece

A manufacturing method, comprising:

• electrical discharge machining a workpiece using an electrode to form an aperture in the workpiece, the workpiece extending between a face surface and a back surface, and the electrical discharge machining comprising plunging the electrode into the workpiece through the face surface;
• measuring an EDM voltage indicative of a gap voltage between the electrode and the workpiece using a high frequency measurement device to provide an EDM voltage measurement signal indicative of the EDM voltage, wherein the EDM voltage is measured by the high frequency measurement device at a measurement frequency equal to or greater than ten kilohertz;
• and
• determining whether the electrode has broken through the back surface using the EDM voltage measurement signal.

A manufacturing method, comprising:

• electrical discharge machining a workpiece using an electrode to form an aperture in the workpiece, the workpiece extending between a face surface and a back surface, the workpiece secured to a support by a fixture, the electrical discharge machining comprising plunging the electrode into the workpiece through the face surface, and the electrode supported by and electrically coupled to a guide;
• measuring a measurement voltage between the guide and the fixture indicative of a gap voltage between the electrode and the workpiece using a measurement device to provide a measurement signal indicative of the measurement voltage, the measurement device electrically coupled to the guide and the fixture;
• and
• determining whether the electrode has broken through the back surface using the measurement signal.