Makino drew the focused gaze of many IMTS 2014 attendees with its exhibit of a new horizontal machining concept — its a51nx-5XU with a newly conceived fifth-axis table and work-pallet magazine, presenting machine shops with additional options for planning and producing complex parts with optimal efficiency. According to the developer, it will make a difference for shops manufacturing parts for medical systems, aerospace production, or any application requiring multi-face machining.
“When looking for a small, five-axis machining solution, companies are typically limited to single-pallet-load vertical machining centers,” explained Makino’s product line manager for horizontal machines, Dave Ward. “The a51nx-5XU stands apart with its horizontal orientation, integral cast fifth-axis table, and integrated workpiece automation. Together, these features provide for a highly productive, highly reliable multi-axis machining solution that eliminates recutting of chips, stack-up errors and challenges of five-axis part loading.”
Ward called the newly modified design a “perfect blend of capabilities” for producing rotating cutting tools, or complex aerospace, medical and prototype parts.
The linear X, Y and Z axes of the a51nx-5XU are built from the same structure as Makino’s established a51nx HMC. The rigid bed casting has a three-point leveling system for solidity and stability in operation.
A tiered-column design redirects machining forces and resists deflection, even high in the Y-axis, according to Makino.
Reliability in performance also is available via the linear guide system.
The option of installing fifth-axis functionality as an aftermarket adjustment is not new – and it's a choice taken by various machine shops presented with the need to improve efficiency for producing complex parts. However, Makino noted that five-axis retrofits frequently are less stable than the original design. Reliable cabling for the extension is a further consideration.
The a51nx-5XU offers a single casting design that houses and integrates the B- and C-axis’ twin direct-drive motors. This solitary piece provides rigidity with a minimized profile that reduces interference between the spindle and worktable. All cables are concealed to the roofline of the machine’s splashguard and can be accessed and managed outside of the machining area.
The a51nx-5XU rotary table design eliminates the stack-up errors, loss of rigidity and cable management challenges common to many table-on-table designs, Makino noted.
The large direct-drive motors within the B and C axes provide rapid traverse rates of 75 rpm and 150 rpm. Jacket cooling of the direct-drive motor stators and bearing perimeters guard against thermal deformation, prolonging reliability. The C-axis also benefits from a 50-taper interface and clamping mechanism, the developer indicated, which provides location and clamping of the workpiece within the five-axis machine envelope.
Makino emphasized that the work-pallet magazine (WPM) simplifies and optimizes the automation capabilities for the a51nx-5XU, specifically for pallet changes in horizontally oriented five-axis production. It also , and facilitates unattended operation for more value-added labor demands.
The WPM takes the place of a traditional horizontal pallet changer, performing automated loading/unloading according to a design similar Makino’s matrix tool magazine: the transfer of workpieces from magazine to worktable is quick and reliable, with storage capacity of 22 different workpieces up to 300 mm diameter by 300 mm tall.
An optional, larger-capacity WPM is available to store up to 58 workpieces with diameters up to 200 mm. Parts are mounted directly to the 50-taper dual-contact tool holders (BBT50) and stored in the WPM matrix. This is allows shops to set up the a51nx-5XU for continuous, unattended manufacturing for high-mix, low-volume and low-mix, high-volume production.
The WPM system includes a work-setting station (WSS) for loading and setup operations, with convenient and ergonomic operator access. A work data management panel allows operators to process data defined per pallet, and manage work schedules.
For advanced levels of scheduling control and machine networking, the a51nx-5XU can also be equipped with Makino’s MAS-A5 control system.