Titanium Machining Technologies Create New Opportunities for Patriot Machine Inc.

“We invest to innovate, be challenged and open windows of opportunity that didn’t previously exist,” said Bob Burns, vice president and cofounder of Patriot Machine Inc. “As one of the first companies to invest in large 5-axis aluminum machining capabilities, we established ourselves as true innovators in aerospace manufacturing. We are continually investing and engineering new ways to improve our efficiency, all to supply what matters most to our customers: quality parts delivered on time.”

“Impossible” is a word not commonly used at Patriot Machine of St. Charles, Mo., a world-class manufacturer of complex aerospace parts and assemblies. Patriot has built its business on successfully completing the most difficult manufacturing challenges through innovative process solutions and machining technologies. As an added service to original equipment manufacturers, Patriot collaborates with design engineers to optimize part designs and improve manufacturing efficiency.

Patriot cemented its reputation with the addition of new and advanced titanium machining capabilities. Judy Burns, president and cofounder of Patriot Machine, recognized the importance of expanding with differentiating equipment. After thorough analysis, the company decided on two Makino 6-axis horizontal machining centers coupled with a 32-pallet automated material-handling system, as well as one Makino T4 5-axis horizontal machining center.

“Aircraft manufacturers will be amazed by what we are now able to accomplish in titanium,” Bob said. We’re even seeing value-added benefits, such as longer tool life, which we believe can more than quadruple with additional research and process refinements. But right now, we’re working to inform OEMs of the T2’s capabilities, opening new opportunities for them to pursue greater complexity in their part designs.”

An Eye for Innovation

Incorporated in 1991 by Judy and Bob Burns, Patriot initially opened for business as a CAD/CAM services company. At the time, CAD/CAM was a new and developing technology, but the husband-and-wife team saw the potential to push the envelope for complex part designs.

“Early CAD/CAM technology was far from perfect, and initially, some simple designs required more time to complete than drafting by hand; however, its true capabilities were discovered in more complex three dimensional designs,” explained Bob. “It was really the inevitable growth in design complexity that pushed the need for CAD/CAM. And when you think about the parts being produced today, there’s really no way these designs could be accomplished by hand.

“You don’t grow a business by focusing on jobs that come easy to you. You have to take on the complex jobs that push your team to develop new and better processes. We started this business out of our garage, and today we’re working in an 82,000-square-foot facility and employ more than 130 talented individuals. This growth could not have been possible without overcoming some difficult challenges and having the foresight to invest in the most capable aerospace machining equipment. With this equipment and our technological know-how, our customers believed in us and gave a chance.”

Changing the Aerospace Landscape

Aerospace manufacturers have been producing aluminum parts for several decades; however, with recent advancements in machine capabilities, the complexity of these parts has grown exponentially. Patriot was able to gain a leg up on the competition during this dynamic transition period by making early investments in large 5-axis aluminum machining capabilities.

“Whenever you can take an assembly and reconfigure it into a single monolithic design, you’re not only improving manufacturing efficiency but also reducing part weight and cutting costs throughout the supply chain. Key benefits include fewer parts to be purchased, managed, produced and stored,” said Bob. “When Makino released its MAG3 5-axis horizontal machining center we immediately recognized its potential for producing more complex features in a single setup. This enabled us to gradually evolve from simple assembly designs to complex monolithic structures while establishing ourselves as the go-to resource for customers interested in making this transition.”

One example of this capability was a variable-inlet application that originally required 96 individual components. As a result of cost-cutting initiatives, the customer approached Patriot with the challenge of manufacturing their newly designed monolithic components. Patriot viewed this request as an opportunity to demonstrate the MAG3’s capability of machining complex contours and closed-angle features.

Due to the success of its initial investment in 2004 of a MAG3 and an 8-pallet automated material-handling system, Patriot has since expanded its aluminum machining capacity by adding a second MAG3H. The pallet system is now integrated to feed both machines.

The company attests that the evolution it has experienced with aluminum part designs has been a unique learning experience and has prepared Patriot for similar experiences in hard-metal part designs.

Improving Titanium Machining Efficiency

Over the last decade, aerospace industry demands for higher fuel efficiency have led many aircraft manufacturers to use more titanium in aircraft designs. Previously, Patriot produced titanium parts on 5-axis vertical machining centers; however, according to Bob, operators and engineers experienced a variety of limitations when developing processes for some of the newer part designs.

“There is nothing more frustrating than designing the perfect process and then having to scale it back due to machine limitations,” said Bob. “You can plan processes to work around issues, but in the end you’re still hindered from reaching your full potential. We decided to invest in the next level of technology to remove these limitations.”

Patriot evaluated a variety of machine technologies and processes, including gantries and cryogenic machining. Based on its previous experiences with Makino’s MAG3 machines, the company decided to learn more about Makino’s T4 5-axis horizontal machining center and T2 6-axis horizontal machining center.

“Where most other machine tool manufacturers made slight modifications to existing products and marketed them as titanium machining centers, the T-Series machines were the first built specifically for titanium machining of aerospace components,” said Bob. “Makino got the basics right from the very beginning, looking at what was most important, including proper cooling, vibration damping and sufficient spindle power and torque. Every aspect of the machines demonstrated that Makino clearly understood the challenges our industry was experiencing.”

A primary component of Makino’s T-Series machining centers is its ADVANTiGEâ„¢ technology, a set of key machine features Makino developed to counteract the traditional limitations of low metal-removal rates and limited tool life in titanium machining. These features include a high-power, high-torque tilting spindle, Collision Safe Guard and Autonomic Spindle Technologies, high-pressure, high-flow coolant system, vibration damping system and a rigid machine construction.

Patriot described ADVANTiGE technology as the secret ingredient that ties everything together. And while the company specifically liked the coolant system, vibration damping, high-capacity automatic tool changer and HSK-125A spindle interface, it’s the complete harmony of all ADVANTiGE technology features that has enabled Patriot to reduce cycle times and improve the overall quality of its complex stainless steel and titanium parts.

The four titanium parts were machined consuming less of the available tolerance than traditional machines are capable of holding. When the very first four parts were assembled, we found that the assembly consumed only one-fourth of the available tolerance,” described Bob. “The ability to consistently produce part features to tighter tolerances will not only help OEMs achieve tighter assembly tolerances, but will also allow features such as flanges, stiffeners and ribs to be designed thinner. Ultimately, this level of capability will enable OEMs to significantly reduce the overall weight of aircraft for improved fuel efficiency.”

Adapting to New Opportunities

For the highly skilled engineers at Patriot, the T-Series machines represent an opportunity to work together to develop new techniques and manufacturing methods that few in the industry thought possible.

“In a way, we feel like the pioneers of titanium machining all over again,” says Paul Rosner, Patriot’s technical operations and tool applications engineer. “The spindle manipulation, indexable pallet and tooling options enable us to reach more complex features and apply more aggressive cutting techniques.”

Rosner detailed the T-Series spindle design as a flexible powerhouse due to the improved tool-gripping rigidity, 21,000 pounds of retention force of its HSK-125 interface and 1,100 ft-lbs of torque. The rigid HSK-125 holder and retention force has enabled Patriot to eliminate previous stack-up inaccuracies, deflection and fretting of the holder. According to Rosner, “Now a 23.6-inch tool runs as smoothly as an 8-inch tool. We’re seeing little to no hesitation in our toolpaths, even when roughing with full, simultaneous-axis motion. And while the T-Series spindle design provides just a bit more power than our previous spindles, the torque curve allows us up to four times the cutting speed.”

Rosner reaffirmed that this level of capability is dependent on other features of ADVANTiGE, emphasizing the importance of the coolant system capacity as well as the machine and spindle rigidity for enhanced tool life. “When it comes to titanium machining, coolant delivery is critical; without enough coolant supply, a machine can burn up a tool within 20 seconds,” he said. “The T2 and T4 have alleviated these concerns with a robust coolant system that includes through-spindle delivery. With a steady flow of 53 gallons per minute at 1,000 psi through the spindle, chips and heat from the cutting zone are effectively displaced, providing us with noticeable improvements in tool life. As we continue to refine our processes, we anticipate even greater tool longevity.”

Patriot illustrated the effectiveness of the combined ADVANTiGE capabilities through a titanium pivot hub component that featured four holes located on a vertical sidewall, just inches above a horizontal plane approximately 20 inches long. According to Rosner, the difficult-to-reach hole locations could not have been machined using previous equipment; however, the T2’s rigid spindle and robust coolant options enabled engineers to reach across the horizontal surface with a 23.6-inch tool, only thousandths from the part floor.

Getting More Out of Every Setup

Walter Burns, Bob’s brother and Patriot’s manufacturing engineering manager, asserted that some of the biggest benefits to productivity have been increased part access and tool capacity. “The more rotational motion a contoured or multi-sided part requires, the more the T2 outperforms,” he said.

One contract that Patriot recently won, in part because of the T2’s capabilities, was a part requiring plus and minus 45 degrees of tool rotation. Using previous machinery, the job would have required five setups and multiple fixtures; however, the 6-axis capabilities of the T2 with its unlimited B- and C-axis rotation enabled the company to combine four setups into one to complete the part with improved accuracy.

“Our throughput capabilities for complex stainless steel and titanium applications are some of the most competitive in the industry, and they only stand to improve with our recent investment in a 32-pallet automated material-handling system. We will not have to tear down and set up our fixtures for recurring production. We’ll leave the fixtures set up on the work cubes and cycle them as needed, allowing for single-piece flow and no setup cost on complex parts,” said Walter.

With this increase in available throughput, Walter noted the elevated importance of the T2’s optional 192-tool-capacity automatic tool changer, explaining that in order to ensure maximum utilization rates while minimizing labor, the company opted for the largest magazine available.

“A typical application is programmed with about 40 tools, and while 90 percent of these tools are shared between jobs, it’s to our benefit to have additional capacity for the tools that are different from part to part and for more complex parts in the future,” he said.

Leading the Titanium Market

According to the Burns family, confidence is the most important benefit of the Makino machines. “It’s a great time to be in aerospace manufacturing, and we’re excited about the future,” said Bob. “Whether a job calls for aluminum, titanium or stainless steels, we have the capabilities to complete complex jobs–winning with tighter tolerances, lower cycle times and overall best value per part than ever before.”

Patriot has noted several plans for expansion following the completed installation of its new automated material-handling system. “As awareness of our new hard-metal manufacturing capabilities continues to grow, we’re looking at two additional T2s to complete the cell. Our T4 is arriving this fall to take on applications up to four meters in length, and we have expectations of a second T4 in the future,” explained Bob.

“Makino tackled the challenges of titanium head on. Their engineers took a step back and reevaluated the machining process from the ground up to ultimately provide an effective solution. Most aerospace manufacturers have yet to realize the full capabilities of the T-Series and ADVANTiGE technology. But when they do, it’s guaranteed to change the way titanium and other hard-metal components are designed and manufactured.”