Editing Electrical discharge machining (section)

===Wire-cut EDM===

The wire-cut type of machine arose in the 1960s for making tools ([[die (manufacturing)|dies]]) from hardened steel. The tool electrode in wire EDM is simply a wire. To avoid the erosion of the wire causing it to break, the wire is wound between two spools so that the active part of the wire is constantly changing. The earliest [[numerical control]]led (NC) machines were conversions of punched-tape vertical milling machines. The first commercially available NC machine built as a wire-cut EDM machine was manufactured in the USSR in 1967. Machines that could optically follow lines on a master drawing were developed by [[David H. Dulebohn]]'s group in the 1960s at Andrew Engineering Company<ref>Dulebohn, "Tracer controlled machining by electrically induced erosion", {{US patent|3614372}}, filed 4 December 1969, issued 19 October 1971.</ref> for milling and grinding machines. Master drawings were later produced by computer numerical controlled (CNC) plotters for greater accuracy. A wire-cut EDM machine using the CNC drawing plotter and optical line follower techniques was produced in 1974. Dulebohn later used the same plotter CNC program to directly control the EDM machine, and the first CNC EDM machine was produced in 1976.{{sfn|Jameson|2001|pp=12–17}}

Commercial wire EDM capability and use has advanced substantially during recent decades.<ref name="Rogers_2018">{{citation |last=Rogers |first=Barry |year=2018 |title=The Remarkable Abilities of Wire EDM |journal=TechSpex |url=https://www.techspex.com/knowledgecenter/guide-to-buying-machine-tools/buying-a-wire-edm |access-date=2018-05-21 |postscript=. |archive-date=2018-05-22 |archive-url=https://web.archive.org/web/20180522112039/https://www.techspex.com/knowledgecenter/guide-to-buying-machine-tools/buying-a-wire-edm |url-status=dead }}</ref> [[Feed rate]]s have increased<ref name="Rogers_2018"/> and [[surface finish]] can be finely controlled.<ref name="Rogers_2018"/>