Every moldmaker strives for higher cutting speeds and reduced electrode wear to increase overall mold production efficiency. However, as burn speed/spark power increases, so, too, does risk of damage to the part surface, especially in those applications where cavity undersizes are tight.

A big spark in the front of the sinker EDM electrode is acceptable, because the undersize can be controlled with the Z axis. However, on the sides of electrodes, the spark cannot be greater than the undersize, because it will destroy the sidewalls of the cavity. Therefore, the small undersize restricts the maximum power that can be used. Another special generator function allows certain sinker EDMs to vary the sizes of the sparks at the fronts and sides of electrodes, as opposed to using the same spark the whole way through a burn. An intelligent speed power generator with such functionality applies the electrical current only when and where necessary, eliminating the lateral sparking that historically creates disturbances on the sides of mold cavities, keeping electrode wear in check and optimizing cutting speeds. This functionality also allows the electrode to have maximum power in the front of the cavity without destroying the sidewalls or creating too big of a gap on the sides. This can potentially double or even triple material-removal rates over what is typically produced with small undersizes.

To extend electrode life, this functionality’s higher potential amperages and lower “on” times translate into less wear when roughing. It should be noted, however, that the same generator technology without this functionality still reduces electrode wear, but it does not increase the cutting speed as much.