An apparatus and method of electrochemical machining utilizes a computer controlled static array of electrically insulated cathode sections to selectively and individually energize the electrodes for the purpose of shaping the surface of a part. The tightly clustered array of electrodes can be formed by individual wires as an example. The waste reaction products may be managed so as to improve machining accuracy. The electrodes can be composed of materials capable of generating an oxide layer or that resist electrolytic dissolution to combat the problem of crossover erosion in closely spaced conditions. An alternative approach to remedy crossover erosion is to extend the reach of insulation into the gap space between tool and part.