The first EDM drilling units of Heun to be placed on the market were modules that consisted of an all-purpose, adaptable eroding head with servo-unit and a mobile generator with high-pressure pump. These modules are still available now, although with an improved design.
They are still used to carry out special tasks, for example, the removal of rivets from the outer plating of airplanes during maintenance, relief drillings, bleeder holes as well as cooling holes into metallic moulds, drill holes into injection nozzles and EDM drilling with extremely pointed angles.
According to Heun, the eroding unit can be applied in many different fields of EDM drilling. Every kind of conductive material can be machined, independent of softness or hardness, the company says. The fast EDM drilling speed is the main feature of this machine.
The unit is of compact design and appropriate for machining especially big work pieces. The generator and the monitor are located within the sold, mobile control cabinet. The water-cooled generator is extendable up to 80 ampere. The operating interface, which is – as Heun says it - self-explanatory, is controlled by touch-screen terminal. The eroding head can be attached to existing machining centres or to robot tooling.
Independent use by mounting on a stand or drill rig is also possible. Copper or graphite can be used as electrode material brass. Different ceramic guides can be installed. Therefore, the electrode diameter range can be modified from Ø 0.3 – 3.0 mm. Electrodes of Ø 0.1 – 6 mm can be clamped with special collet chucks.
Optionally, machining with electrodes of up to 50 mm as well as with form electrodes is possible, the company says. Every electro-conductive component can be machined. Until now, eroding heads of different length have been constructed. At present, 3,000 mm is the vastest travel distance that has been reached. The head-generator unit has an analysis tool to control the drilling process. It is also possible to connect the unit to the particular machine und to pass signals to this respective machine.
The functions are the same as on standard EDM drilling machines. A special feature is that the spindle can also be locked in place in order to be able to carry out die-sinking or cut off parts as, for example, threaded bolts or sheet-metal parts.