The world’s most accurate Ram EDM, Makino’s EDAC1, is capable of producing corner radii of 0.00019 inches (0.005mm) and surface finish quality of 0.000024 inches (0.6 micron) Ry. This machine achieves positional and pitch accuracies of ±0.00004 inches (1.0 micron) through new mechanical and electronic designs, including a cubic structure and removal of overhangs at axis limits. Additional mechanical design features include an integral, liquid-cooled Z-axis thermal stabilizer for depth accuracy of ±0.00004 inches (1.0 micron), and a newly designed C-axis head designed to maintain indexing accuracy of ± 2 arc-seconds.