Unattended Sinker EDM Burns, Shaped Diffuser Holes

For discharge machining of cooling air holes and shaped diffuser holes in blade and vane segments, Makino offers its EDBV3 fast-hole drill EDM. Designed for aerospace applications, the EDM provides speed, flexibility and reliability to effectively produce a range of hole shapes and sizes using a single setup, reducing required tool variety and overall cycle times, according to the company.

The EDBV3’s X-, Y- and Z-axis travels measure 370 × 270 × 500 mm (14.5" × 10.6" × 19.6"), and the worktable measures 250 × 270 mm. The maximum workpiece weight load is 5 kg, with 15 kg available as an option. The rotary C-axis head can spin as fast as 1,000 rpm and features an Erowa compact chuck that enables automatic changing of electrode diameters as small as 0.2 mm (0.008"). A rigid guide arm assembly holds, locates and supports the die guide, which can be alternatively used as a programmable W axis. An integrated “middle-guide” system can be applied for small-diameter electrodes, preventing whipping, bending and vibration.

Makino’s Model Plan software system is integrated into the EDM’s controller, providing input screens with direct G- and M-code programming formats. An electrode length management system tracks electrode wear and automatically exchanges electrodes when lengths become too short. A highly sensitive breakthrough detection circuit helps to prevent back wall impingement during blade and vane cavity wall penetration.

The EDM is equipped with an automatic toolchanger (ATC) and automatic guide change (AGC) system to enable unattended burning of cooling hole diameters. An electrode set combining the electrode holder and die guide into a common assembly improves reliability with simple and precise automated exchanges. Together, these features are said to enable 30-sec. ATC and AGC exchanges.