If your business requires electrical discharge machinery that is precise and accurate, then EDM is the best option. It removes bits of conductive metal using electrical discharges between the cutting tools. It is often used when conventional metal removal is nearly impossible. Here are the different types of EDM you should consider.
Wire EDM uses a fine electrically charged wire during the process to shape a metallic object. Although the wire gets used up entirely, all these machines have a drive system that automatically replaces the used cables with new ones. The wires that are used are quite thin, with a diameter of 0.002 to 0.013. The cuts, however, are typically larger, but only slightly. The output is usually measured in square inches per hour. The cables never actually touch the material themselves, a gap of at least 0.001 inches is maintained.
The wire and the piece of work are continuously washed down with dielectric fluid. Sometimes both of them are entirely submerged in the liquid. The dielectric fluid makes it possible to cut at much faster speeds.
There are many manufacturers in the markets, but make sure to get the finest wire EDM machine possible for the best results.
Ram/ Sinker EDM
A sinker is used to make complex shapes in tool or die applications. For example, plastic injections molds or metal stamping dies. It usually consists of a graphite electrode that is plunged in the work piece to create the required cavity. This causes sparking over its surface, as features close the sparking gap. During the process, both the electrode and the piece are entirely submerged in dielectric fluid.
The required shapes are usually quite complicated, which makes it necessary to carry out several passes. Where the first pass will remove the larger quantities of the material, ending with a rough piece. The final pass will ensure the surface is smooth, and the details are accurate.
Hole Pop/ Drill EDM
These ability to cut hardened metals and alloys while leaving a perfect finish is precisely why it is best suited in hole-carving processes. A machine called hole popper can be used for these cases. It uses a rotating conductive tube as an electrode, which is attached to the positive pole of a power supply. The piece is attached to the negative, and the space between the two is flooded with dielectric fluid to flush the cut. The electrode moves deeper into the part using the path cleared during the process, as the electrical pulses remove material. It is ideally used for material that requires starter, vent, cooler, or any blind holes.
If you are using computer numerical control equipment, it is possible to drill sequential holes in the material without the need of an operator or further setup.
Hole popper EDM can also be used to create the pilot hole necessary for wire threading. Wire EDM can then be used to thread the cable through the hole, after which it will make the necessary cuts.