Makino HMCs Extend Machining Capabilities

Makino’s new 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 560mm (22.0”) X-axis and extended Y- and Z-axes of 640mm (25.2”) for an industry-leading total axis volume of 8.1ft³. Its additional Y-stroke yields a 14% larger working envelope.

The standard a61nx features a 730mm (28.7”) X-axis, 650mm (25.6”) Y-axis and extended Z-axis of 800mm (31.5”). An optional tall column on the a61nx expands the Y-axis to 730mm (28.7”), 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 430mm (16.9”) and 510mm (20.1”), respectively.

Increased Spindle Power
The a51nx and a61nx machines offer new, more powerful standard and optional spindles. The standard spindle is a 14,000rpm design with 240nm of duty-rated torque and 22kW of continuous output, a 19% increase over the previous model. An optional 300nm 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.

Higher Machine Strength and Rigidity
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.

Improved Productivity
The nx machines are designed with a 1G-axis acceleration supplemented by high-power servo motors and enhanced casting rigidity for faster acceleration. 

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.

Expanding Reliability
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.