chuck the part into and out of the machine,” said Pfluger. The standard configuration of the EDBV3 includes a 24-station tool carousel system and 24 holder assemblies to fully tool up the machine. The tool carousel can also be exchanged as a pallet- ized magazine for extended hours of automated operation. Critical process issues address machining speed as well as
breakthrough detection. “As you drill through the outer skin and you break into a hollow cavity, you have to avoid machining the interior back wall of that cavity. That’s called back striking. If an adjacent cavity feature is machined, it will change the air flow and affect cooling effectiveness. Special machine genera- tor circuitry has been developed that can detect breakthough within one second or 0.040" [1 mm],” said Pfluger. EDM drilling on the EDBV3 is performed fully submerged under water for higher part quality, improved stability and up to 10 times faster processing speed compared with conven- tional technologies. To improve productivity, the EDBV3 uses a single-electrode processing approach, which avoids the high
cost of custom multi-electrode holders and standardizes the tool holders with a flexible and cost-efficient system. For untended burning of varying cooling hole diameters, the EDBV3 features a combined automatic tool change (ATC) and automatic guide change (AGC) system. The patented electrode toolholders combine the electrode holder and die guide together into a common assembly, providing ATC and AGC exchanges in 30 seconds. In addition, changing to a dif- ferent brass electrode diameter is simplified. Makino developed the EDBV3 fast hole drill EDM for pro- duction drilling of critical cooling air holes and shaped diffuser holes in blade and vane segments.
Machining Choices for Other Components
Capacity for machining structural titanium and related components has also expanded the investment in advanced machining technology. Aerospace Dynamics International Inc. (Valencia, CA), increased its titanium machining capacity