EDM (Electrical Discharge Machining)

Articles • April 1, 1999 • R. Dean Brink

Continual Improvement

With innovations in technology, EDM has found its place as a reasonable alternative to other precision machining operations. This article reviews five recent developments: the introduction of a new electrode material, operations that replace dielectric fluid with gas, the development of electro-conductive powders, the EDMing of nonconductive materials and a method for producing complex part geometries with simple electrodes.

Articles • April 1, 1998 • Ed Kwasnick

Diamond Tames Graphite’s Bite

Graphite electrodes are extremely difficult to machine because of the material's abrasiveness. This article explains why it takes an endmill with a CVD diamond coating and multiple flutes to cut graphite without wearing tool quickly.

Articles • April 1, 1998 • Dandridge Tomalin

Why Do EDM Wires Break?

Adequate flushing is needed to keep EDM wires from breaking. This article explains why wires break, and how dielectric fluid delivered with sufficient flow and pressure can prevent these failures from occurring even in less than ideal conditions.

Articles • April 1, 1998 • Steve Slate

Bonded Graphite Electrodes

To produce graphic electrodes for EDMing large cavities, shops sometimes must machine the piece in smaller sections and bond them together. This article explains how to build and use a bonded graphite electrode so that a ridge at the electrode's bond line can be avoided.

Articles • April 1, 1998 • Christopher Wilkens

Wire EDM Filtration Comes of Age

Centralized mineral filtration for wire-EDM dielectric fluid can remove contaminants down to the 1-micron level and dispose of them in an environmentally responsible way. This article describes the mineral filtration process and compares it to the other common filtration methods.

Articles • August 1, 1997 • David Doyle

Burning Brightly

The more sophisticated die-sinker EDMs on the market today possess enough intelligence to monitor cutting conditions and make necessary adjustments on the fly. This article describes the technology that drives these smart machines and the "fuzzy logic" they use to maintain an optimal spark.

Articles • April 1, 1997 • Jimmy Sherman

Grading Graphite

This report details the results of a test of graphite electrodes. The test compared the performance and machinability of three graphite grades, ranging from an inexpensive coarse grade to a relatively costly ultrafine grade.

Articles • April 1, 1996 • Christopher Wilkens

EDM Wire Covers All the Angles

With wire EDM, the properties of the wire will have a large impact on the performance of the operation as well as the ease of rethreading. This article discusses the properties that ensure a good spark and reliable performance even when cutting at an angle. Real-world examples are given of users who have improved their operations by changing the type of wire they were using.

Articles • April 1, 1996 • K.P. Rajurkar

A Spark of Intelligence

EDM cutting conditions change throughout the cutting process as the part thickness and the level of dielectric contamination fluctuates. This article describes an experimental setup that can monitor these fluctuations and adjust the EDM's settings to maintain an optimal spark.

Articles • April 1, 1996 • Lawrence Rhoades

Understanding EDMed Surfaces

EDMing removes material at such high temperatures that the process produces metallurgical changes in the material surrounding the cut. This article discusses the various surface effects and how they can be detected and measured. It also reviews the different methods for correcting or removing the surface flaws and roughness caused by EDMing.

Articles • April 1, 1995 • Anders Utterstrom

Optimal Automation

The efficiency of a die-sinker EDM operation can be enhanced by automating at least part of the work handling or tool handling. This article describes the automation that is available, from the simplest electrode grippers to fully automated toolchanging systems.

Articles • April 1, 1995 • Jimmy Sherman

EDM Conquers Copper

Copper is difficult to EDM because of its high thermal conductivity. This article discusses the electrodes and machine settings to use for this demanding task.