A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece. The wire electric discharge machine includes: a remaining length calculation unit that calculates a remaining length of the wire electrode based on electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin. The electrode winding coefficients depend on a winding density of the wire electrode, an inner width of the wire bobbin, a wire diameter of the electrode wire, and a winding tension of the wire electrode. The bobbin draw-out radius correlation information is correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin.

A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece. The wire electric discharge machine includes: a remaining length calculation unit that calculates a remaining length of the wire electrode based on electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin. The electrode winding coefficients depend on a winding density of the wire electrode, an inner width of the wire bobbin, a wire diameter of the electrode wire, and a winding tension of the wire electrode. The bobbin draw-out radius correlation information is correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin.

A wire electrical discharge machine includes a filter for removing machined swarf produced by electrical discharge machining from a working fluid, and a heating device for heating the working fluid stored inside the filter.

A wire electrical discharge machine includes a filter for removing machined swarf produced by electrical discharge machining from a working fluid, and a heating device for heating the working fluid stored inside the filter.

An electrical discharge machining electrode wire includes a core including a copper or a copper alloy, and a covering layer that covers a periphery of the core and includes a zinc. The covering layer includes an outermost layer consisting of an -phase of a copper-zinc based alloy. The outermost layer has a Cu concentration of 12 to 20 mass % and a variation range within 5 mass % in the Cu concentration in a longitudinal direction of the electrode wire.

An electrical discharge machining electrode wire includes a core including a copper or a copper alloy, and a covering layer that covers a periphery of the core and includes a zinc. The covering layer includes an outermost layer consisting of an -phase of a copper-zinc based alloy. The outermost layer has a Cu concentration of 12 to 20 mass % and a variation range within 5 mass % in the Cu concentration in a longitudinal direction of the electrode wire.

An electrical discharge machining electrode wire includes a core including a copper or a copper alloy, and a covering layer that covers a periphery of the core and includes a zinc. The covering layer includes an outermost layer consisting of an -phase of a copper-zinc based alloy. The outermost layer has a Vickers hardness of 200 to 300 Hv.

An electrical discharge machining electrode wire includes a core including a copper or a copper alloy, and a covering layer that covers a periphery of the core and includes a zinc. The covering layer includes an outermost layer consisting of an -phase of a copper-zinc based alloy. The outermost layer has a Vickers hardness of 200 to 300 Hv.

A method of manufacturing a last chance screen for an aircraft engine includes forming an array of holes through a metal sheet with a wire electrode using electrical discharge machining. The array of holes comprises a plurality of holes. Each hole of the plurality of holes comprises a first end and a second end and is surrounded by a wall section such that the last chance screen is defined by the plurality of holes and the plurality of wall sections. The first and second end of each hole are widened by either applying a flow of an abrasive flow medium to the array of holes in two directions or using a conical sinker electrode on either side of the metal sheet. Shaping the first and second end of each hole results in an airfoil-shaped cross-section of each wall section.

A method of manufacturing a last chance screen for an aircraft engine includes forming an array of holes through a metal sheet with a wire electrode using electrical discharge machining. The array of holes comprises a plurality of holes. Each hole of the plurality of holes comprises a first end and a second end and is surrounded by a wall section such that the last chance screen is defined by the plurality of holes and the plurality of wall sections. The first and second end of each hole are widened by either applying a flow of an abrasive flow medium to the array of holes in two directions or using a conical sinker electrode on either side of the metal sheet. Shaping the first and second end of each hole results in an airfoil-shaped cross-section of each wall section.