VMC With Linear Motor Technology

The VL 50 is a vertical machining center featuring linear motor technology. The successful application of linear motors on the X, Y, and Z axes, says the company, offers speed and motion control to perform high speed point milling in multi-axis contouring applications. Linear technology is also said to provide high geometric and positioning accuracies, offering consistently high precision even on long job runs. The low-heat, counteracting, permanent magnet linear motors the company uses are said to eliminate mechanical backlash, vibration and noise normally associated with ballscrews and other types of drives. The company says it developed the design of this machine to satisfy needs in the mold and die, aerospace, and precision parts industries for high speed machining of high temperature alloys and hardened tool steel components. These applications were chosen because of the severe requirements for 3D contouring, tight tolerances and fine surface finishes. The VMC has an X, Y, Z work envelope of approximately 16" × 12" × 8", and its tool changer can accommodate 16 tools. Its rapid traverse and cutting feed rates in all axes are 1,574 ipm (40 m/min). The acceleration/deceleration rate is 1 G. Spindle speeds range from 300 to 30,000 rpm. The control system is a Fanuc 15i MB. A custom alloy is used on the sliding components--column, spindle head and carriage--which the company says reduces the weight of these components while maintaining excellent stiffness and thermal stability. The three-point, heavily ribbed cast iron bed weighs more than 14,300 lbs. (6,500 kg) and fully supports ultra-high machining speeds. A precision glass scale feedback system detects 0.1-micron increments. Its ISO 230-2 bi-directional accuracy is less than 2 microns. All axes incorporate roller guideways that are mounted on hand scraped surfaces to ensure accuracy, reduce wear and volumetric tolerance degradation, according to the company. Other design features are said to include excellent coolant and chip management to meet the needs of high performance cutting and enhanced ergonomics and safety systems for operators, setup, and maintenance personnel.