Makino BX3

The Makino BX3 is an EDM hole-drilling machine built for one job: drilling cooling film holes in turbine engine blades and vanes at high production volumes. It has 370 mm (14.6 in) of X, 270 mm (10.6 in) of Y and 750 mm (29.5 in) of Z, an integral two-axis rotary table with A: 360º and B: ±140º, and takes workpieces up to 11.81"Ø x 11.81" and 20 kg (44 lb).

Makino describes it as a further specialization of the EDBV3 for small aero-engine part details, and the differences are about cycle time. Rapid positioning is 10 m/min (394 in/min) where the EDBV3 moves at 5 m/min (197 in/min), and the rotary table indexes at 10rpm. The B-axis swings ±140º against the EDBV3's -110/+30°, and Z travel is 750 mm (29.5 in) against 500 mm (19.7 in). The rotary table is laid out so that a typical blade or vane sits close to the center of rotation, which keeps the X/Y moves between holes short.

The generator is Makino's digital ES200A, rated up to 100 Peak Amps, with adaptive control that detects break-through within 1 second. That matters when drilling into the hollow internal cavities of a cooled blade, where the electrode must stop before it strikes the far wall. All machining runs submerged in a programmable rise and fall work tank of 800 mm x 740 mm (31.50 in x 29.13 in); Makino states that submerged operation is critical for stable break-through.

The 24 station ATC takes fully supported electrodes up to 700mm (27.6") long, and the simplified electrode holders let tool changes happen without moving or draining the tank. Flushing comes from a 10MPa (1450 psi) diaphragm pump, with on-board water filtration and de-ionization monitored by the control. The control is Makino's Hyper-i with dedicated EDM drilling functions. A full CE enclosure is standard, and maintenance access is at the rear so several machines can stand side by side.