Aerospace shop runs five-axis machines through paces.
Valent Aerostructures (Kansas City, MO) meticulously selects every machine tool purchase it makes, and only those machines that provide the perfect combination of reliability, production value and lowest cost per part, as well as the lowest cost of ownership, are even considered. A machine that makes it through the aerospace company's extensive in-house evaluation must then prove its worth as far as performance, accuracy and increased metal removal rates are concerned.
The company is a supplier to major aircraft builders such as Boeing, Spirit Aerosystems, Lockheed Martin and Gulfstream. It operates out of nine facilities, manufacturing small and large, highly complex components and major structural assemblies for both commercial and military aircraft. One of Valent's newest facilities is in Washington, MO, where the company recently acquired new machine tools to increase production capacity and enhance manufacturing capability.
Valent Aerostructures has been an aerospace supplier since the mid-1970s and has experienced significant annual growth since that time. The Washington, MO, facility employs 150 people while Valent Aerostructures has a combined total of 630 people across its nine facilities. In addition to its machining operations, the company does its own sheetmetal fabricating, heat treat and aging, and part-surface finishing.
The company evaluated a number of machines for the Washington site, putting them to work cutting metals including titanium and aluminum. According to Perry Pecaut, general manager at Valent Washington, machines from Mazak (Florence, KY) provided the best economics for Valent.
"The Mazak machines we evaluated, as far as performance, accuracy and metal removal rates, showed to offer by far the best combination of production value, lowest cost per part and lowest cost of ownership. And we have not been disappointed because, plain and simple, the machines are truly making us much more competitive," says Pecaut.
"We really did our homework determining if the machines would give us the best bang for our buck," continues Pecaut. "Additionally, we were sold on Mazak the company. It is well established and one that continuously invests in the development of new technology so that it can always offer a very diverse machine product line."
Two of the shop's recently purchased Mazaks are Vortex 1060V/8 full simultaneous five-axis VMCs with hard-metal machining packages slated for machining the shop's titanium components. And while those machines are equipped for that purpose, Valent is incorporating additional Vortex 1060V/8 machines that will provide high-speed cutting capability for the shop's aluminum parts.
Valent's unique strategy is to create two separate, fully automated machining lines. One will be for hard metals (titanium), while the other will provide high-speed machining for aluminum components. The Vortex 1060V/8 is available in three standard spindle configurations—high-torque with 5000-rpm spindle, general-purpose with 10,000-rpm spindle, and high-speed with 15,000-rpm spindle. The ability to use the same model machine for both lines, yet for two very different materials, will further increase the shop's production value.
"We continue to improve our material removal rates and cycle times as we learn the machines' capabilities." Modular Automation
Additionally, both machining lines will incorporate Mazak's Palletech Automation System that will provide for complete untended operation. The system is modular, so Valent will be able to easily and cost-effectively expand it as more machines are added to both lines.
For what the shop calls its Hard Metal Palletech Machining Line, Valent has the two-level configuration of the Palletech system that incorporates 24 pallets and a load/unload station. The system currently serves the shop's two Vortex 1060V/8 machines that are equipped with HSK 100A , 50-hp (37.2-kW) B-axis tilting spindles providing maximum speeds of 5000 rpm and continuous torque ratings of 368.8 ft-lb (500 N•m). And because the machines will run continuously with the Palletech system, Valent opted for a large 160-tool storage capacity for each of them. In the future, the shop will add 24 more pallets to the Palletech system and two more Vortex 1060V/8s equipped exactly the same as the existing two for a total of four machines and 48 pallets in its Hard Metal Palletech Line.
For its High-Speed Machining Palletech Line, as Valent refers to it, the shop will incorporate another four Vortex 1060V/8 machines and another Palletech system. The first of the four machines and the Palletech system will arrive in the fall of 2012. The machines for this line will feature Mazak's 15,000-rpm high-speed spindle configuration.
Valent also has several other models of Mazak machines, including a Vortex 1400/160-II full simultaneous five-axis VMCr, two Horizontal Center Nexus (HCN) 4000-II HMCs and a Vertical Center Nexus (VCN) 700D HS VMC with special high-speed package and fourth axis.
For its two HCN 4000-II machining centers, Valent is incorporating robotics and automated part processing. One of the machines will use a Fanuc stand-alone robot and be dedicated to producing a specific group of parts, while the other machine will be set up for the use of quick-change fixturing to cut several smaller statements of work.
"We really push the Vortex 1060V/8 with its high-torque spindle," says John Gupton, technical lead and project manager at Valent. "And we continue to further improve our material removal rates and reduce cycle times as we learn the machines' capabilities and experiment with different tooling and processing strategies."
For Valent's aluminum machining operations, Gupton says the Mazaks provide incredible high-speed machining capabilities. To maximize efficiency in high-speed machining, Valent's VCN 700D-II HS, for example, features the productive combination of a 40-taper, 40-hp (29.8-kW) spindle together with a maximum speed of 18,000 rpm and generating torque up to 191 ft-lb (259 N•m). Plus, the machine's rapid traverse rate of 1968 ipm (50 m/min) and its 2-sec tool-to-tool change time further reduce non-cut time.
Also benefiting Valent's aluminum part-processing operations are the HCN 4000-IIs that feature 40-hp, HSK 63A taper high-speed spindles with 18,000 rpm. The machines provide the shop with rapid traverse rates of 2362 ipm (60 m/min) per axis at 0.8 G acceleration. An advanced design, along with a compact spindle for low vibration and low heat generation, allow the machine to maintain extremely high levels of accuracy.
Valent's Vortex 1400/160-II machining aluminum parts is equipped with a 13,000-rpm, 100-hp (74.5-kW) tilt/rotary spindle, 120-tool storage capacity and rapid traverse speeds of 1260 ipm (32 m/min) in the Y axis, 787 ipm (20 m/min) in X and Z. This not only slashes machining times for the company's components, but also boosts processing efficiency through its two-pallet changer that automatically shuttles two big 157.48 × 49.21" (4 × 1.2-m) tables in and out of the machine's work envelope.
In addition to speed and power, five-axis machining capability is critical to Valent reducing its part-processing operations and increasing its throughput. According to Gupton, full, simultaneous five-axis machining on the Vortex machines is extremely beneficial because a great deal of the shop's complex work demands it, and some of the simpler work becomes even simpler. Monolithic Challenges
The aerospace industry's growing practice of combining several components into bigger monolithic parts machined from solid blocks of material results in highly complex angles and deep cavities, Gupton notes. Those characteristics require precise five-axis machine movement to prevent tolerance and blending issues when processing a contoured part surface that requires using multiple tools, such as a larger tool for roughing, then a smaller one for finishing and reaching into deep cavities. For this, the Vortex 1400/160-II provides a tilt/rotary A/B axis of ±40°, while the Vortex 1060V/8 delivers 150° B-axis tilt and 360° of rotation in the C axis.
Prior to five-axis capability, machining such components would have involved several operations and multiple machine setups. But with the Mazak machines, Gupton says, the shop—in almost all instances and no matter what the level of complexity—completes such parts in only two operations as opposed to the four or more previously needed.
Another big challenge for Valent when machining its complex aerospace components, especially those machined from hard metals, is managing tool life. Because of its aggressive material removal rates and running most machining operations untended, Valent has its Mazak machines laser-scan cutting tools prior to machining to verify the correct tool and that it hasn't worn beyond an acceptable amount.
Valent is considering monitoring its machine tools through the MTConnect protocol, which is another reason the shop decided on Mazak machines. With MTConnect capability, Valent will be able to collect data on overall machine utilization and monitor the occurrence of machine alarms, spindle loads, and more for continuously improving part processing.
"As we continue to win more major aircraft assemblies work, we are quickly approaching a point where all manufacturing operations are done in-house, giving us complete control over our processes," says Pecaut. "And as this happens, these machines will play a key role in allowing us to continuously increase our production capacity and efficiently meet the needs of our customers."