Originally titled 'Three-Axis VMC Limits Vibration'
Hwacheon’s Sirius UM three-axis vertical machining center is designed for high-precision performance machining, such as that required by die-mold applications. The machining center features a 20,000-rpm high speed spindle with rapid positioning rates of 24 m/min. A 850 × 500 mm (33.46" × 19.70") work table offers an 800-kg (1,7640-lb) load capacity. The machine provides strokes of 750 × 500 × 450 mm (29.53" × 19.70" × 17.72") for X, Y and Z. Feed performance is enhanced by the Z-axis six-block LM guide. The servomotor is coupled directly to the drive, and the tensile preloaded ballscrews enable smooth operation. According to the company, the 40-taper tools can be changed in 2.5 sec.
The spindle is integrated with the motor to limit vibration, noise and power loss at high rotation speeds, the company says. The cooled jets of oil are injected directly into the spindle bearing for improved cooling, and the motor and spindle assembly are jacket-cooled to limit heat displacement. A bilateral gate structure is said to distribute vibration, weight and heat throughout the entire frame, while the short distance between the spindle and body is designed to promote stability over long cycles.
The machine is equipped with the Hwacheon frame-displacement control system (HFDC) software, which dynamically compensates for changes in machine kinematics due to temperature, vibration or changes in the tool itself. Standard integrated software developed in conjunction with FANUC includes tool-load detection; a high-efficiency contour-control system; Optima cutting-feed optimization routine; and the Hwacheon spindle-displacement control.