Used machine tools
The electro erosion machining is based on the effect exerted by the disruptive discharges (electric discharge accompanied by sparks) on the workpiece produced by an electrode, and on cooling the deteriorated particles in a highly localized way under this effect. To obtain this reaction, a vacuum bubble is caused by the flow of current in a dielectric (an electric insulating fluid). Ionized, this bubble implodes and deteriorates the material by generating a spark. For this same reason the term "spark machining" is also used.
The dielectric fluid where the workpiece swims is constantly filtered. If it is water that is used, a de-ionization resin is used to make it lose its ionized feature.
This electro erosion method greatly facilitates machining operations on conductive materials, even if they are extremely hard. It is also particularly recommended in the latter case. Metal parts, whether alloyed, steel hardened or carbide corresponding to the profile of a material likely to be treated by electro erosion.
If the electro erosion is not intended to offer substantial machining speeds, it nevertheless allows to achieve and above all high levels of accuracy (at a scale of more or less 5 microns).
There are three main types of EDM machines
, and so many families of machine tools corresponding thereto: spark erosion
, wire erosion
and EDM driller
. Even second-hand (carefully checked beforehand), these machines have a good reputation in the business.
It’s a matter of hobbing erosion when hobbing into the workpiece an electrode of a shape complementary to that of the workpiece. This type of machine (hobbing electroerosion) has digital control versions (CNC spark erosion
) and we could state AGIE, Charmilles
, CDM Rovella, Ona, and Walter among major manufacturers.
Charmilles and AGIE along with Castek particularly, also manufacture fast drilling electro erosion machines. Here, we make use of a tubular electrode to drill into very hard parts.
As far as wire electroerosion is concerned, it consists of cutting a workpiece using a wire to which is printed a plan and an angular movement. A principle applied by machine tools designed by the firms Agié
, Charmilles, and Fanuc
The second-hand machines
proposed by RDMO make subject to a check by technicians specialized in this type of machines.