Makino EDAC1

The Makino EDAC1 is a small sinker EDM built for ultra-precision work in small electronics and micromachining. Its envelope is compact: 220 mm (8.66 in) of X, 180 mm (7.08 in) of Y and 220 mm (8.66 in) of Z over a 350 x 250 mm (13.8 in x 9.8 in) table, with a 450 x 350 x 200 mm (17.7 in x 13.77 in x 7.87 in) work tank and a workpiece limit of 50 kgs (110 lb).

The machine is defined by its tolerances rather than its size. Makino states mechanical alignment of each axis of 2 microns (0.00008") or smaller over the full stroke, and positional tolerances of ±1 micron (0.00004"). It quotes a smallest inside corner radius of 5 microns and surface finishes down to 1.3 µin Ra (0.25 µm Rz). The Z-axis has a core-cooled ball screw stabilizer that allows continuous high-speed jump motions with ±1 micron depth control, which is what keeps fine ribs and slots consistent in depth from the first to the last.

The generator's peak machining current is 30 amp, and electrodes are limited to 5 kgs (11 lb). Both figures place the EDAC1 at the fine-finishing end of the work: it is not the machine for large graphite electrodes or heavy roughing. An optional Mi C-axis adds indexing with positioning accuracy of ±2 arc seconds, for electrodes that must be set at precise angles.

The worktable is stationary, with a three-sided rise-and-fall work tank that opens up access for setting up parts and watching the process. Control is through Makino's Hyper-i system. Against the EDFH-1, which shares the 350 x 250 mm (13.8 in x 9.8 in) table and 220 mm (8.7 in) of X but has 300 mm (11.8 in) of Z, the EDAC1 is the machine chosen for accuracy rather than reach.