Makino EDBV3

The Makino EDBV3 (Electrical Discharge Blade and Vane) is an EDM drilling machine for the cooling film holes and diffusors in blades and vanes for aerospace and power generation. It has 370 mm (14.6 in) of X, 270 mm (10.6 in) of Y and 500 mm (19.7 in) of Z, an integrated 2-axis rotary table with A: 360° and B: -110/+30°, a 24 tool changer and a 790 x 611 mm (31.1 in x 24.1 in) work tank.

The central problem in drilling a cooled blade is back-striking: once the electrode breaks into the hollow cavity, it must stop before it damages the opposite wall. The EDBV3 has a break-thru detection circuit as standard, and Makino states that detection occurs within 1 second or 0.040" (1.0mm) of depth. All machining is done fully submerged in de-ionized water, which Makino says gives the fastest cycle times and the most stable break-thru, and which also cuts over-spray, so the splash guards of older drilling machines are not needed. A Middle Guide supports long electrodes so they do not whip or bend.

Setup time is attacked on two fronts. The rotary table positions the part so several sides can be drilled in one setup, and the Die Guide and electrode are loaded and exchanged together as one assembly, which keeps a combined ATC and AGC exchange within 30 seconds. The Hyper-i control adds pre-programmed cycles for diffuser shapes, electrode length management and graphical pick-up cycles.

The workpiece limit is low: 5 kg (11 lb) on the rotary table as standard, or 15 kg (33 lb) with the option. That is enough for a turbine blade or vane, but rules out larger components. Rapid traverse is 5 m/min (197 in/min). The BX3 shares its X and Y travels but has 10 m/min (394 in/min) rapids and 750 mm (29.5 in) of Z, while the EDBV8 keeps the same rotary table and 24 tools but extends X to 800 mm (31.5 in) and Y to 600 mm (23.6 in) for larger parts.