My Favorite CNC EDM for Machining

Posted on Dec 26, 2020

CNC EDM

CNC EDM is ideal for processing hard-to-machine materials such as instrument steel, carbides, and exotic alloys like Inconel and Hastelloy. It has the benefit of not bringing any cutting forces into the workpiece, so there is no distortion, making very thin parts possible to be made. Furthermore, with radii not much greater than that of the wire itself, wire EDM can create internal corners.

CNC EDM is a modern form of Electrical Discharge Machining. A CNC EDM unit can machine deep ribs or cavities in a workpiece in a quicker yet more accurate and precise manner as the CNC technology enhances the capability of EDM. EDM is essentially a method that cuts, or more specifically, erodes, a workpiece by discharging electrical currents onto its surface. In order to generate the program necessary for the optimum erosion process, the EDM computer implements an automated technique.

CNC stands for Computer Numerical Control. It analyzes the optimum erosion mechanism by entering data, displaying the number of electrodes requested, and automatically produces and executes the program. The user will apply the knowledge to the CNC with an automated strategy, creating technology tables with automatic strategies. Often the devices decrease the operator's preparation time and increase the precision and efficiency of the process. A CNC EDM machine is a piece of equipment that employs such a system.
 

General Features of CNC EDM

The general features of the EDM machine include simultaneous multi-axis machining for a wide range of functions; a mechanical structure head configuration to remove vibrations created by the rapid acceleration and deceleration of the EDM machine (this ensures the development of precision components); multiple applications by CNC-integrated functions; angular or angular or deceleration of the EDM machine.

To hold thermal deformation down to a minimum, the floor, column, head, and both X and Y tables are made of reinforced fine-grained cast iron blended with graphite in a symmetrical pattern. Also on the computer, a paper cartridge filtering system is standard. As an alternative, the Dielectric Filtering System is provided, which provides more than 10,000 working hours of filter element life.
 

Wire CNC EDM 101

Understanding where to apply this approach helps to learn a little bit of it. Wire EDM uses electrical arcing to erode the material, as does EDM sinking and hole cutting. Placed under running water, the electrically conductive workpiece is carried close to the electrode. High voltage bolts through the void at the nearest point, blasting a microscopic piece of material from the surface, swept away by the water.

Arcing begins at a very high frequency, widening the distance between the instrument and the workpiece eventually. If the distance is too wide, an arc can not form. Therefore, as the workpiece erodes, the electrode is pushed closer to the workpiece. To optimize the cutting speed while avoiding wire-to-workpiece touch, modern machines use sophisticated gap-monitoring algorithms.

The arcing occurs over a large area during sinking EDM, so the electrode progresses steadily. Wire EDM, by comparison, usually uses a wire just 0.01 in diameter. This does not require much material to be removed to cut a course so that the wire can pass through the workpiece. The wire is vertical in a standard CNC machine and the workpiece pushes towards it in the directions of X and Y. It is fed through the void so the wire still erodes, so it is technically consumable. Inclining the wire allows tapers to be cut onto the workpiece.
 

:: Read More: What Does CNC EDM Wire Cut Do?
 

Machining of CNC EDM Wire

EDM is ideal for processing hard-to-machine materials such as instrument steel, carbides, and exotic alloys like Inconel and Hastelloy. It has the benefit of not bringing any cutting forces into the workpiece, so there is no distortion, making very thin parts possible to be made. Furthermore, with radii not much greater than that of the wire itself, wire EDM can create internal corners.

Two passes are common in traditional metal cutting to achieve the desired final size and finish. For Wire EDM, the same holds true. Turning up the electrical power more easily erodes the alloy, but the finish fails. For a second pass, reducing the strength produces a finishing cut that leaves a strong surface.

Wire EDM has the ability for improved content use, unlike machining techniques to produce chips. As the wire cuts very little material, there is always a big internal slug left behind. (Something of particular concern when cutting high-value materials!) Milling or grinding will translate this into a pile of chips, but it can be saved and used on another job with wire EDM.
 

Wire CNC EDM Tooling Implementations

Perhaps the most well-known application is to cut the extrusion die profile. These are typically manufactured from H13 tool steel for aluminum extrusion. A hole is first drilled (often also by EDM) through the die blank, and the wire is then threaded through. To cut the appropriate profile, the CNC system passes the blank through the cable. The wire can be tilted to cut forms with tapered sides on modern wire EDM machines. Often useful for producing punch tools is Wire EDM. To cut the profile desired, a blank of tool steel is passed across the cable. Again, tapers are highly capable of cutting
 

Applications Other than Instrumentation

Wire EDM can cut any 2D profile from a conductive material. In certain cases, broaching and milling might be feasible, but wire EDM provides many benefits:

  • Develop internal corners that are sharp.
  • No cutting forces, enabling very small pieces to be machined.
  • Capacity, at reasonably high speed, to cut very hard stuff.
  • Reasonable for machining without supervision.
  • Remove the design limitations imposed by the traditional removal of metal.
  • No special-purpose instrumentation was required.
  • Better use of content.


Precision machine parts are developed in one class of wire EDM applications, particularly where they are required in small volumes. A good example will be the sewing machine parts, gears, and splines. Medical equipment, surgical machines, and small hand instruments are other types. The ability to cut complicated paths in very hard materials such as stainless steel makes wire EDM extremely cost-effective for both of these.
 

Dream Uses Regarding Making Use of CNC EDM

Tooling industries use wire EDM facilities to produce extrusion dies, although there are even broader uses. For low-volume development of complex components such as gears, splines, medical equipment/tools, consider using this technique. The pace, consistency, cost, etc can surprise you pleasantly!
 

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