Next Generation Small Part 5-Axis Medical Machining

Manufacturers of medical parts have long understood the positive impact that 5-axis machining can have on productivity and quality by simply consolidating operations. The a51nx-5XU 5-axis horizontal machining center from Makino, Inc. (Mason, OH) raises these capabilities to a new level, building on the quality, durability and reliability of the nx-series next generation horizontal machining platform. With its integral cast 5th-axis table and work-pallet magazine, this machining center enables manufacturers of complex parts to obtain the highest levels of utilization and efficiency.

When looking for a small 5-axis machining solution, shops are typically limited to single-pallet-load vertical machining centers. The a51nx-5XU stands apart with its horizontal orientation, integral cast 5th-axis table and integrated workpiece automation. Together, these features provide a highly productive, highly reliable multi-axis machining solution that eliminates recutting of chips, stack-up errors and challenges of 5-axis part loading for a perfect blend of capabilities for the manufacturing of medical components. The linear X, Y and Z axes of the a51nx-5XU are built from the same proven structure as the industry-leading a51nx horizontal machining center. Its rigid bed casting with three-point leveling system provides a solid foundation for all critical machine components.

A tiered-column design redirects machining forces and resists deflection even high in the Y-axis. These features are further complemented by high-performance linear guides, for long-term reliability. Altogether, this machine design offers dynamic stiffness and exceptional vibration management for the highest degree of cutting stability.

With increasing demand for small part 5-axis machining, many companies are adding aftermarket 5th-axis rotary tables to 4-axis machining centers. However, these 5-axis retrofits frequently offer less rigidity and pose several challenges in cable interface management. The a51nx-5XU avoids these issues with a single casting design that houses and integrates the B- and C-axis’ twin direct-drive motors. This single-piece casting provides ideal rigidity and 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 easily 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.

The design of the large direct-drive motors within the B and C axes enhance the productive capabilities of the a51nx-5XU, providing rapid traverse rates of 75 rpm and 150 rpm to minimize non-cut times. Jacket cooling of the direct-drive motor stators and bearing perimeters eliminate all risk of thermal deformation to help maintain repeatable, high-accuracy performance with exceptional quality. The C-axis also benefits from a BT-style 50-taper Big Plus (BBT50) interface and clamping mechanism that provides location and clamping of the workpiece within the 5-axis machine envelope.

Traditionally, one of the biggest challenges associated with 5-axis part production has been automated capabilities. For this reason, the a51nx-5XU comes with a unique work-pallet magazine (WPM) that simplifies pallet changes in horizontally oriented 5-axis applications, and facilitates unattended operation for more value-added labor demands. The WPM takes the place of a traditional horizontal pallet changer, providing manufacturers with automated load/unload capabilities for maximum machine utilization. This technology follows a similar design to that of the proven matrix tool magazine, ensuring quick and reliable transfer of workpieces between magazine and machine worktable.

The standard WPM offers storage capacity of 22 different workpieces with sizes up to 300 mm in diameter by 300 mm tall. An optional, larger capacity WPM provides storage of 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 capability makes the a51nx-5XU an ideal solution for continuous, unattended manufacturing in both high-mix, low-volume and low-mix, high-volume production environments. The WPM system includes a dedicated work-setting station (WSS) for loading and setup operations, providing convenient and ergonomic operator access.

A nearby work data management panel allows operators to process data defined per pallet and manage work schedules. Priorities can be set and changed for each pallet, helping to accommodate for engineering changes or urgent one-off part orders. For advanced levels of scheduling control and machine networking, the a51nx-5XU can also be equipped with the MAS-A5 control system.

Makino also offers their iQ300 Precision Micromachining Center that incorporates the latest advancements in machine and spindle design, and unparalleled component temperature control. This machine also utilizes 0.005 micron scale feedback for superior sub-micron accuracy. “Medical devices continue to decrease in size and increase in demand,” says John Bradford, the micromachining R&D team leader at Makino. “With a thermally stable, vibration-free, high speed spindle that is ideal for fine detail machining and ultra-precision accuracies, as well as Hybrid ATLM for tool matching and blending, the iQ300 is the perfect micromachining center for these challenging micro applications.”

The iQ300 features a 45,000 rpm HSK-E32 spindle equipped with a patented core-cooling, under-race and jacket spindle temperature control system that virtually eliminates thermal growth, deflection or vibration, even during long hours of high-speed machining. To ensure microscopic blending and matching of surfaces when machining with different tools, the iQ300 integrates the proprietary Hybrid Automatic Tool Length Measurement System (ATLM). A 40-tool magazine assures a wide variety of tooling to address an extensive variety of projects. The worktable measures 600 mm x 400 mm (23.6 in x 15.7 in) with X-, Y-, Z-axis travels of 400 mm x 350 mm x 200 mm (15.7 in x 13.8 in x 7.9 in), respectively. This large work table and ample travels assures the capability to do multiple set-ups and utilize precision chucks and vices.

The iQ300 also incorporates the user-friendly Professional 5 Control with proprietary, next generation Super Geometric Intelligence (SGI.4) software. This control has been developed specifically for high feed rates, tight tolerance machining of complex, 3D, contoured shapes involving continuous tiny blocks of NC data to ensure production rates faster than standard CNC systems while maintaining unsurpassed accuracy.

Makino also offers their F-Series vertical machining center that provides stiffness and rigidity for chatter-free cutting, agility for high-speed /hard-milling and accuracies for tight tolerance blends and matches typical of complex, 3D contoured geometry associated with medical production. “The F-Series has been built from the ground up for speed and precision,” states William Howard, the vertical machining product manager at Makino. “The machine design begins with a unique axis configuration – featuring no overhangs – and incorporates large castings that provide a robust cutting platform. It then integrates 8 mm fine pitch ball screws and 0.05 micron scale feedback as standard equipment to provide superior precision. Even the servo systems are tuned for peak performance. Together, these features reduce variability for hours of continuous, tight tolerance machining.”

The F-Series consists of two models: the F3 and the F5. The smaller F3 features X-, Y-, and Z-axis travels of 25.6 in, 19.7 in, 17.7 in respectively, a 33.5 in x 19.7 in table and a maximum workpiece size of 33.5 in long x 19.7 in wide x 17.7 in tall. By contrast, the larger F5 features X-, Y-, and Z-axis travels of 35.4 in, 19.7 in, 17.7 in respectively, a 39.4 in x 19.7 in table and a maximum workpiece size of 39.4 in long x 19.7 in wide x 17.7 in tall. Both the machines have a table load capacity of 1,432 lb and a 30-tool magazine provides capacity for a wide array of tooling. Included in the standard configuration of the F-Series machine is a highly productive 20,000 rpm, HSK-63A spindle which incorporates patented core-cooling, under-race and jacket spindle temperature control system. The two-range spindle supplies unique, wide range capability with the stiffness and rigidity at lower ranges for roughing operations and vibration-free, chatter-free production of small details and fine features utilizing small tools at high rpm.

The F-Series utilizes the Professional 5 Control that affords the perfect blend of a Windows CE graphical user interface (GUI), touch-screen selection offering instant access to information literally at your fingertip, user-friendly, efficient PC-like capability for data management and editing and the networking and storage capability of a data center. Also featured is the proprietary, next generation SGI.4 software for high feed rates and tight tolerance machining of complex, 3D, contoured shapes. SGI.4 helps provide the lowest cycle times and costs achievable by reducing machining cycle times on medical parts by as much as 40 percent when compared to most other control technologies.

“F-Series machines quickly pay for themselves,” adds Howard. “These machines deliver positioning accuracies and repeatability in the microns, the spindle assures capability to address a wide variety of tooling and machining applications, and SGI.4 provides unsurpassed accuracy and speed in tough, challenging, complex geometries. This platform is an ideal choice for shops looking to get top shelf machining performance and superior machining results at a reasonable investment – a real value proposition.”

Makino, Inc., 7680 Innovation Way, Mason, OH 45040-8003, 513-573-7200, Fax: 513-573-7360, www.makino.com.