Big River Manufacturing Keeps Accuracy Afloat in Medical Machining

“There’s manufacturing, and then there’s manufacturing with purpose,” explained Tom Roehm, CEO and co-owner of Big River Engineering and Manufacturing. “We believe that manufacturers can be good community partners by providing solid jobs, training a skilled workforce and standing as an example of environmental conservation and sustainability. At Big River, the city of Memphis matters, and through unparalleled service focused on efficiently delivering high-quality precision products, we aim to bring manufacturing back to the city’s urban core in a strong and sustainable way.”

Big River Engineering and Manufacturing has been an integral part of the Memphis community and regional medical-device manufacturing market since 2007, when it was acquired by industry veterans Tom Roehm and Hugh Fraser. The two initially met on a Memphis conservancy board, prior to their cooperative business venture. When a local manufacturer put itself up for sale, the pair saw the perfect opportunity to bring their aspirations to life.

The company took on the Big River name, and was restructured and refocused into profitability within 18 months, saving 12 valued jobs in the process. In 2009, Big River moved its operations into a 9,000-squarefoot vacant warehouse in downtown Memphis. The facility was renovated to earn Leadership in Energy and Environmental Design (LEED) Silver certification, fulfilling Roehm and Fraser’s commitment to sustainable practices.

“We were moving in the right direction and steadily growing; however, maintaining this momentum required a better, more efficient approach to our manufacturing processes,” said Roehm. “In some of the more complex component designs, we were experiencing a lot of variation in finished parts. Additionally, several of our customers were starting to develop some exciting products within orthopedics, and we aspired to be a part of it. To earn that business, we needed to build the capacity and capabilities for not just the work of today, but tomorrow as well.”

As a requirement for producing medical parts, Big River is subject to capability studies by the U.S. Food and Drug Administration (FDA), to verify that the company is following current good manufacturing practices (CGMPs). To help ensure that its products consistently meet applicable requirements and specifications, the company required a high-performance machining center, capable of producing tight tolerances of plus or minus 0.03 mm on a routine basis, with a level of confidence that would allow for unattended operation.

“Producing quality parts isn’t good enough in today’s market. You have to do so while following regulatory standards in a way that remains cost competitive,” said Roehm. “I don’t think you can overcome these pressures without high-performance machining equipment. Our investment in a Makino a51 horizontal machining center has allowed us to replace three vertical machining centers while simultaneously improving final-part quality and consistency.

“It’s this level of capability that has alleviated external pressures and allowed us to focus on the things that matter most.”

Taking Production to the Next Level

Like many other manufacturers, Big River’s path toward investing in high-performance equipment was neither a quick nor easy process. The company spent nearly a year determining the types of technologies that would best fit its needs. By IMTS 2010, the company was prepared to take the next step. “We had put together a list of key questions and concerns to approach machine tool manufacturers with,” said John Monty, operations manager at Big River. “Surprisingly, one of the simplest questions seemed to cause the most concern: How do you measure the accuracy and repeatability of your machines? Almost every representative was stumped and couldn’t provide a straightforward response. The only company that could definitively answer the question was Makino.”

Roehm agreed and said, “We were also impressed with the level of dedicated support that Makino placed behind its equipment. We felt that as we grew, Makino would have our back and would help us along the way. This was also a huge factor in our final selection of the a51.”

After integrating the a51 into its manufacturing processes, Big River wanted to take its production capabilities to the next level and felt that automation would allow the company to do just that. With the help of their sales rep, they were able to do a solid comparison between a pallet pool and Makino’s MMC2. The MMC2 was chosen for its fluid production scheduling and expansion capabilities, and would support continued growth of Big River’s high-mix, low-volume production environment. Drawing upon its long-standing relationship with Single Source Technologies (SST), the company finalized its purchase of an MMC2 configured with six pallets in 2012.

To ensure that its operators were accustomed to the transition toward high-performance equipment and automation, Big River sent several staff members to Makino’s technical training courses during installation. “Makino’s training facility is world-class, and the instructors there are fantastic,” said Monty. “The Makino programmer who wrote the code for the MMC was the person who worked with us to build the system for our a51. This helped us really grasp the philosophy behind the Makino way of programming, and it enhanced our confidence and flexibility when we returned to Big River.”

Advanced Medical Machining Capabilities

Big River’s a51 cell currently manages 77 different part varieties, in materials such as aluminum, titanium, stainless steel and plastics. The switch from vertical machining centers to the a51 horizontal provided substantial reductions in in-cycle non-cutting times, through faster tool changes and rapid rates. Additionally, the jump to a 14,000-rpm spindle enabled Big River to reduce its average cycle times by 15 to 20 percent.

“In rpm-related machining using smaller tools, or when machining materials such as aluminum, we’ve seen as much as a 40 to 50 percent reduction in cycle times,” said Monty. “If you combine that with our automated efficiencies, we are achieving a 55 to 70 percent increase in throughput on high-rpm applications.”

Another critical component of the a51 has been through-spindle coolant technology. This feature, combined with the machine’s inherent structural and spindle rigidity, has provided the company with a 15 to 20 percent increase in tool life. According to Monty, these numbers have since increased by an additional 15 percent, following a switch to a premium-grade coolant.

“Through-spindle coolant has had a dramatic impact on tooling choices, as well as surface finishes,” said Monty. “When machining medical parts, fine finishes are a necessity. All of the jobs we do require a 32-micro-inch surface finish or better. And in terms of accuracy tolerances, the most common standards from our customers are at plus or minus 0.1 mm. But we really like to take on projects with feature tolerances of plus or minus 0.01 to 0.03 mm. Our previous equipment could not have produced these tolerances, so the a51 has really opened up opportunities for us on parts that require a greater degree of precision.”

According to Big River, parts pulled from the a51 cell typically feature better fitting in final-part assembly and require less hand finishing. In fact, the FDA capability studies conducted on the a51 cell reflect these statistics, increasing the company’s standings.

Big River believes that a big part of this upswing in quality is a result of its newfound tooling flexibility through the a51. With improved rigidity and access to higher spindle speeds, the company is able to use smaller-diameter tooling; it can also accommodate additional operations, such as deep-hole drilling.

“Our approach to tooling and secondary processes has greatly expanded,” said Monty. “We have jobs where we’ll run a 0.020-inch diameter ball-nose endmill as a finishing tool, and we’ve drilled holes that are as small as 0.012-inch diameter on the a51. Many jobs that had been done as multi-piece construction are now machined completely on the a51. We can achieve more detail in our part and remove secondary operations like plunge EDMing. This increases our efficiency and allows us to touch the part fewer times, leaving less chance for errors. This is just another way that the a51 helps us increase our flexibility, quality and throughput.”

A Facility That Doesn’t Sleep

Big River typically runs six different jobs per day on its automated cell; the cell’s MAS-A5 control system coordinates these jobs, keeping operators informed on part progress.

“Our biggest challenge is keeping the machine fed,” said Monty. “We do a lot on the front end to make sure the materials are ready to go into the machine.”

The single-machine, multi-pallet arrangement helps the company increase spindle utilization by providing a degree of unattended operation, especially into the evenings and overnight. Jobs can be set up and fed into the queue without incurring any machine downtime, greatly reducing overall lead-times.

“We are able to minimize the impact of setup time, keeping the spindle running more,” said Monty. “Being able to employ the MMC2’s pallet delivery helps us drive our setup time to near zero. To maximize our efforts, we typically do short runs during the day and long runs overnight, unattended. On a single pallet running 16 hours, we experience spindle utilization rates of nearly 100 percent.”

The company is eager to run a true 24/7 operation and is confident about running overnight, due to the accuracy of the new equipment, the spindle probe used to fine-tune positions of the part as it changes jobs rapidly, and an automatic tool-length measurement system that ensures availability of proper-quality tooling.

“Admittedly, the first night of unattended operation was difficult to swallow—not because the machine wasn’t capable, but rather because the process of releasing control was easier said than done,” said Roehm. “Today, it’s a nonissue. The cell and machine technologies ensure that there are no broken tools, providing for hours of additional productivity. In fact, if there’s any concern, it’s thinking about what life would be like without the technology. In the last 11 months, we’ve achieved 100 percent on-time delivery of parts with zero rejected.”

Roehm is very emphatic about how automation enhances the jobs on his shop floor and provides additional opportunity and job security for his existing workforce.

“In this day and age of high efficiency, the most important part of our operation is our people,” said Roehm. “For critics who say that I’m not creating as many jobs as I could be, I tell them that I’d rather have fewer people working on great technology and pay them more to wear additional hats than to have a deep bench of people earning lower wages. I am very thoughtful about each person I put on my shop floor. Small business is a huge part of the U.S. economy, and we need to find ways to make it continue to thrive. Automation allows our company to do just that and to be able to care for our employees and their families, while remaining competitive with the big guys.”

Riding the Current

Big River sees no signs of slowing in the foreseeable future. In fact, management has plans to expand its cell with four Makino a51nx horizontal machining centers and additional pallet capacity within the next 18 months. The goal is to grow its capacity, by extending the MMC2 to cover the length of its shop.

“We will continue to increase our productivity and customer base through technology,” said Roehm. “We want to buy the best equipment and train the best people, in order to execute our philosophy of producing excellent products in a timely fashion.

“The service from SST has been integral to these goals. We call them anytime if we have a question, and their support is second to none. Between the SST service and Makino technology, we’ve really opened up doors to new opportunities.”

Fraser adds, “We’ve found a sustainable process for growth, quality and overall service to the community. We’re proud of our city and especially those at Big River who have brought us to where we are today. We see a bright future here on the banks of this river.”

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Big River Engineering and Manufacturing
Memphis, Tennessee
(901) 382-0609
www.bigrivermemphis.com