This article originally appeared in Aerospace Manufacturing and Design
One group of participants in the recent Okuma Partners in THINC Winter Showcase, which was held in Charlotte, North Carolina, on December 5th and 6th, chose a different approach to combining their capabilities in the manufacture of a complex 5-axis landing gear concept part. The group involved in the project utilized the products and expertise of Okuma (machining centers), Hainbuch America (precision workholding), Kennametal (tooling), Haimer-USA (shrink fit toolholders), MP Systems (high-pressure coolant and chiller systems), Lyndex-Nikken (5-axis rotary tables), Blaser Swisslube (ester-based coolant), Siemens PL (systems software), and VMH International (systems integration).
Wade Anderson, Okuma Product Specialist and Tech Center Manager, commented, “This particular demonstration, and the others that were presented, provided a vivid example of the success that can be achieved when companies that are leaders in their fields work together to solve customer challenges. As the aerospace, medical, and energy sectors have increased the demand for complex, high-precision parts in relatively limited quantities, both OEMs and their suppliers are faced with the problem of justifying the expense of a dedicated 5-axis machine. Our partners chose to approach the problem by joining their advanced technologies in the creation of a discreet 5-axis module that could be mounted on a 3- or 4-axis machine. The result delivers the necessary capabilities and precision at a much lower cost.”
According to John Soukup, team leader and Regional Sales Manager (Southeast) at Hainbuch America Corporation, “Most demonstrations are devised to show technological advances in terms of mechanical or electronic performance. While new technologies can create cost savings in the long run, few are intended to address the question of initial affordability. It became our team’s goal to develop a system that combined the three ‘P’s’: Performance, Portability, and Price.”
The machining center chosen for the demonstration is an Okuma GENOS M56O-V. Designed to provide customers with Okuma capability and technology in an affordable package, the GENOS M560-V features a 1300x560mm table with X, Y, Z travels of 1050x560x460mm, respectively. The spindle speed is 15,000 rpm, and the tool magazine accommodates up to 32 tools.
Wade Anderson said, “Because this demonstration emphasized cost savings, the GENOS M560-V was the logical choice. It has been well received by our customers, who are looking for an entry-level machining center without sacrificing quality and performance.”
At the base of the group’s system is an 8-inch Nikken, 5-axis rotary table equipped with a wear-resistant carbide worm screw and an iron-nitride worm wheel. The table will hold up to 150 lbs. and is actuated by servo motors linked to the machine control. Rotation is a full 360 degrees, and tilting extends from 0 to 105 degrees. “In 5-axis applications, the tolerances are invariably tight,” says Bob Berongi, Regional Sales Manager at Lyndex-Nikken. “The use of carbide and iron-nitride in the worm screw and wheel is essential to maintaining those parameters and to extending the life of the table.”
The part designed for the demonstration is a complex landing gear part requiring high tolerances and a high finish. Constructed of 7075 T-6 heat treated aluminum, the part is clamped on the ID using a Hainbuch MANDO Adapt workholding system. Capable of both OD and ID operations, the Hainbuch system is designed for fast changeover and high-precision operation. According to Michael Larson, Marketing Director at Hainbuch America, “The ability to quickly exchange workholding components without sacrificing accuracy is essential to manufacturers of complex parts in limited quantities and is a feature of virtually all of our systems. Due to the high finish requirements of most 5-axis parts, the ID system utilizes a mandrel that alternates hardened steel clamps with patented elastomer segments that provide maximum clamping capability without marring the part finish.”
The 7-tool package necessary for machining the part is provided by Kennametal and includes 7792 high-feed cutters with 6mm inserts, MaxiMet® carbide end mills developed for combined roughing and finishing operations in aluminum, several carbide drills of various sizes and, for large bore operation, a Romicron™ boring adaptor. Capable of advancing one micron at each actuation, the Romicron delivers both precision and stability in large bore operations.
Jeff Martin, Kennametal’s Senior Account Manager for the Machine Tool Industry, states, “The investment in quality tooling can only be justified by accurate performance data. Also, tool management is a major contributor to the efficiency of any operation. Our Kennametal NOVO digital tool management system brings an extensive menu of performance measurements to manufacturers, including tool performance, inventory availability, cost-per-part management, productivity, and other factors. Incorporating the NOVO system into our demonstration is essential to verifying our choice of tooling.”
To ensure the highest level of precision, as well as repeatable performance over time, Haimer shrink fit and balanced CAT40 taper toolholders were used. Featuring induction coil heating, the Haimer system provides more than twice the clamping force of the nearest competition. Tom Marron, Atlanta Regional Manager at Haimer, explains, “When it comes to shrink fit toolholders, the balancing system is a critical part of the equation. Our system reduces vibration, resulting in more parts between tool changes, better finishes, and improved performance over time. The versatile Haimer system can be used to balance tools, parts, impellers, grinding wheels, and other metalworking components.”
Following an analysis of coolant requirements for the part chosen, Blaser Swisslube selected an ester-based fluid for its unique polaric ability to form film strength without other additives. Compounded for heat treatment in tough machining applications, the coolant is low foaming for high-pressure usage and maintains its performance over time. Drew Borders, Global Industrial Partnership Manager at Blaser Swisslube, explains, “As metalworking operations have become more precise and complex, the importance of selecting the correct coolant has become a key part of the equation. We refer to our products as ‘Liquid Tools’ because of their ability to heighten the performance and life of critical tooling. We work with factors that are both technology related and ergonomic to compound coolants capable of accomplishing specific functions in a user-friendly environment.”
To maximize coolant effectiveness and efficiently evacuate chips, a VR-8 high-pressure unit from MP Systems is included. Kermit Wright, National Sales Manager at MP Systems, states, “The VR-8 is capable of pumping up to 8 gallons per minute at 1000 psi. However, the Variable Volume feature saves energy and results in improved cooling by reducing the load to the appropriate volume for the individual operation. It also serves to improve the cooling function.” An alarm circuit warns of any clogging or other problems.
The system will be controlled by a Siemens PL (Product Lifecycle) NX control. The integrated CAD and CAM platform will ensure correct geometries while providing full digital modeling capabilities. Geoff Halliday of systems integrator VMH International, notes: “In response to any changes, the system will instantly reconfigure tool paths and other ancillary modifications. Designed for the full integration of manufacturing capabilities, the control platform speeds programming and ensures optimum performance of all operations.
“By providing both ThingWorx augmented reality software from PTC and Siemens PL (Product Lifecycle) NX software, we are able to model the part and generate the G codes and post processor necessary for machining. Other advantages include the ability to measure production efficiency in real time as the part is machined, to read sensor data remotely by phone, and to efficiently introduce changes and modifications as parts or parts families evolve. In discussing the critical factors involved in system integration, Vern Heyer, Founder and President of VMH International, states, “Proper system integration is dependent on identifying the latest and most advanced software tools that are appropriate to the operation. Because any system represents a significant financial outlay, it is vital to define the architecture in such a way that future operations can be accommodated. The system demonstrated here will successfully generate today’s parts as well as tomorrow’s.”*
In assessing the system, Wade Anderson commented: “If a manufacturer or a job shop attempted to assemble a unit such as this, they would, in all probability, call on their traditional suppliers—some of which might not carry the products or possess the knowledge equal to the task. By selectively choosing our Partners in THINC, you can be assured that what was developed here is the product of the ‘best of the best.’”
John Soukup adds, “All of us who worked on this project are extremely happy with the results. Thanks to our combined efforts, we evolved a cost-effective system that puts top-line 5-axis performance within reach for our customers. And that is our goal.”