HMC FOR FERROUS, NON-FERROUS PART PRODUCTION
Makino a51nx and a61nx horizontal machining centers offer a larger work envelope and next-generation productivity, accuracy and reliability beyond that of typical 40-taper machines.
Posted: October 25, 2010
Makino‘s (Mason, OH) a51nx and a61nx horizontal machining centers extend the capabilities of the highly successful a-series with a host of technologies for next-generation productivity, accuracy and reliability. Designed with larger work envelopes, improved casting designs and spindle and axis guide enhancements, the nx machines offer rigidity, speed and precision far beyond that of typical 40-taper machines.
The a51nx and a61nx models boast expanded axis travels to accommodate larger parts or more parts per fixture. The a51nx features a 560 mm (22.0 in) X-axis and extended Y- and Z-axes of 640 mm (25.2 in) for an industry-leading total axis volume of 8.1 cu ft. Its additional Y stroke yields a 14 percent larger working envelope.
The standard a61nx features a 730 mm (28.7 in) X-axis, 650 mm (25.6 in) Y-axis and extended Z-axis of 800 mm (31.5 in). An optional tall column on the a61nx expands the Y-axis to 730 mm (28.7 in), making it beneficial for large die-cast or near-net-shape applications. Thanks to the expanded Z-axis stroke, maximum tool length on the a51nx and a61nx models is increased to 430 mm (16.9 in) and 510 mm (20.1 in), respectively.
The a51nx and a61nx machines offer new, more powerful standard and optional spindles. The standard spindle is a 14,000 rpm design with 240 Nm of duty-rated torque and 22 kW of continuous output, a 19 percent increase over the previous model. An optional 300 Nm spindle designed for high metal-removal rates in ferrous applications is also available. Along with the two new spindles, the current 20,000 rpm core-cooled spindle remains available as an option on the a51nx and a61nx machines.
Casting design and axis guide improvements of the nx machines deliver higher stiffness, load capacities and precision. A new crossed roller guide design yields improved rigidity for higher metal-removal rates, reduced vibration and improved tool life. Several major casting enhancements coupled with the use of cross roller guides enable customers to effectively use the additional 14 percent Y-stroke. The nx machines are designed with a 1 G axis acceleration supplemented by high-power servo motors and enhanced casting rigidity for faster acceleration. To accommodate quicker acceleration/deceleration times, the nx machines add cooling to the ball screw nut in addition to the existing core cooled ball screws.
Additionally, nx models have a standard direct drive (DD) motor B-axis table for dramatically faster indexing time over the previous worm-gear-driven NC rotary table (NCRT). The motor includes an inertia control system that adjusts table speed and acceleration based on pallet payload. Due to the speed of the DD motor, may lead to fewer machines required in high-volume, high-tool-count automotive applications. The DD motor table also reduces B-axis complexity and eliminates backlash and key component wear. The ATC shutter door typically sees millions of cycles over the life span of a machine. On nx machines, a high-speed servo-driven ball screw actuates the ATC shutter door, improving responsiveness, ease of setup and maintenance. The servo axis also reduces exposure of the ATC to the work envelope. The net result is improved reliability and cleaner ATC environments.
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