Horizontal machining centers given performance boost

The new a51nx and a61nx horizontal machining centers from Makino (Mason, OH) offer larger work envelops and next-generation productivity, accuracy and reliability according to the supplier. Improved casting designs and spindle and axis guide enhancements lead to rigidity, speed and precision far beyond that of typical 40-taper machines.

The a51nx and a61nx models boast expanded axis travels to accommodate larger workpieces or alternatively more workpieces per fixture. The a51nx features a 560-mm X-axis and extended Y- and Z-axes of 640 mm (25.2 inches) for an industry-leading total axis volume of 8.1 cubic feet. Its additional Y stroke yields a 14 percent larger working envelope.

The standard a61nx features a 730-mm X-axis, 650-mm Y-axis and extended Z-axis of 800. An optional tall column on the a61nx expands the Y-axis to 730 mm. Thanks to the expanded Z-axis stroke, maximum tool length on the a51nx and a61nx models is increased to 430 mm and 510 mm, 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.

The nx machines are designed with a 1G-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. The DD motor table also reduces B-axis complexity and eliminates backlash and key component wear.-[email protected]