Patent ID: 8470160

Claim:
A method of electrochemical machining, the method including the steps of: positioning a workpiece, which comprises an anode, and a tooling piece, which comprises a cathode, in a first position; moving at least one of the workpiece and the tooling piece toward the other such that the workpiece and the tooling piece occupy a second position; moving at least one of the workpiece and the tooling piece away from the other such that the workpiece and the tooling piece occupy a third position; and during at least a portion of the moving of the workpiece and/or the tooling piece from the first position to the second position and from the second position to the third position, using a power supply to apply a voltage across a gap formed between the workpiece and the tooling piece; during at least a portion of the moving of the workpiece and/or the tooling piece from the first position to the second position and from the second position to the third position, forming an inter-electrode gap between a surface of the workpiece and a surface of the tooling piece, wherein the inter-electrode gap comprises a critical dimension that corresponds to a distance across the inter-electrode gap; as the tooling piece and/or the workpiece move from the first position to the second position, applying the voltage across the inter-electrode gap as the inter-electrode gap narrows from a first critical dimension to a second critical dimension; when the inter-electrode gap comprises the second critical dimension, discontinuing the application of voltage across the inter-electrode gap and discontinuing the movement of the tooling piece and/or the workpiece; after discontinuing movement of the tooling piece and/or the workpiece, holding the workpiece and the tooling piece substantially stationary for a predetermined time period; and after the predetermined time period has elapsed, moving the workpiece and/or the tooling piece to the third position; wherein the movement from the first position to the second position is controlled such that a desired flush of an electrolyte from between the tooling piece and the workpiece is produced; and wherein the first position and the third position each comprise a separated position, the separated position comprising at least a large gap between the tooling piece and the workpiece across which electrochemical machining is not practicable.