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While some manufacturers feel an understandable degree of anxiety over being acquired by a larger company, success stories abound when larger machine shops with canny owners build on the strengths of their acquisitions. In the Northeast United States, two facilities found that by collaborating with their new sibling shop they could build on their collective knowledge base and dramatically improve five-axis machining with a little help from their CAM.

A Tale of Two Facilities

With a skilled workforce of over 850 employees spanning 14 manufacturing facilities across the Northeast U.S. totaling more than 850,000 square feet, communication and collaboration are key within the Momentum Manufacturing Group (MMG). MMG (formerly named NSA Industries) is a leading manufacturer partner to OEMs and product manufacturers, offering a full suite of in-house metal manufacturing and value-added capabilities across a range of markets including semiconductors, medical, robotics, aerospace and defense. The largest metal manufacturing company in the region, MMG machines a range of parts from complex assemblies to large-format components and is vertically integrated from raw materials to post-machining processes. MMG acquired two of its divisions in 2022: Little Enterprises North (Whitefield, Maine) and Evans Industries (Topsfield, Massachusetts).

Evans Industries got its start in the semiconductor industry in 1965 and has typically been involved with roughing larger aluminum parts. While it has three- and four-axis machines, it primarily works with five-axis machining centers. Evans Chief Technology Officer and Mechanical Engineer Dan Golomb has been with the company for fourteen years, and during this time he has seen the company’s fleet of five-axis machine tools expand, beginning with smaller DMG MORI machines, moving to larger, more powerful ones over the years, increasingly equipped with automated pallet changers capable of machining huge parts in only one or two setups. For the past five years or so, Evans has seen overall company growth at 30% year-over-year. “Even during the Covid pandemic, we never closed because demand spiked in the semiconductor and telecommunications industries,” Golomb says. “Demand continues to go through the roof.”

For over 20 years, Little Enterprises North has found success with automated five-axis milling and turning technology, incorporating pallet changers and closed loop programming, primarily in small-part production. The company runs two shifts and over the weekend. “We don’t stop machining when we leave. We have a long-running job set up on a Mazak machine with six pallets to achieve 36 hours of unattended machining,” says Senior Manufacturing Engineer and General Manager Nick Anastasio.

On average, the semiconductor and medical parts that Little Enterprises North and Evans are manufacturing require tolerances starting at ± 0.005 inches with more precise features needing to be held to ± 0.0003 inches. The parts also have complex geometric dimensioning, surface profiles, perpendicularity, true position and flatness. “We are working with everything from forgings/castings to billets,” Anastasio says, “and machining a lot of deep pockets with small internal corners that are hard to reach, in addition to cross holes and complex surface profiles.”

Under MMG, both Little Enterprises North and Evans have invested in conical barrel cutting to save time on finishing passes. Working in parallel, they both latched onto CAM and tooling strategies that dramatically improved machining productivity and part quality. And vitally, by working with the same software and techniques, the two companies developed a collaborative working relationship under their parent company that has made both shops more profitable.

Big Parts, Conical Cutters, Modular CAM

Conical barrel cutting is a milling strategy pioneered by Open Mind Technologies, the producer of the Hypermill modular CAD/CAM software. The company collaborated with cutting tool manufacturer Emuge-Franken to develop and offer conical barrel tools, which Emuge-Franken named “circle segment” end mills. Together with proper CAM software, conical barrel cutters can dramatically reduce cycle times on finishing passes while maintaining tight tolerances by mapping only a part of the circle (a circle segment) on the end mill. This end mill design features unconventional forms with large profile radii in the cutting area of the end mills to enable large stepovers that cut wider swaths of material, enabling fewer tool passes while maximizing tool life and minimizing the number of cusps. The large stepover produces higher cutting forces than standard ball-nose cutters due to the large radii on both the face and radial cutting edges of the tool.

Hypermill had an early advantage in programming for conical barrel cutting, owing to Open Mind’s part in developing the cutting tools and cutting strategy. According to Anastasio, the effectiveness of the conical barrel cutting process prompted him to learn Hypermill CAM programming. “I first became experienced with Hypermill as an engineer with a different company where I selected Hypermill due to its strength with conical barrel cutting for milling aerospace structural components,” he says. “So of course, it was a natural decision to bring Hypermill to Little Enterprises North when I came on board.”

“We are shedding cycle time and creating capacity for more orders down the road.” – Nick Anastasio, senior manufacturing engineer and general manager, Little Enterprises North

In the case of a part that goes into the assembly of a mobile robot system, the machining process starts with two 66-inch diameter sand castings that are machined to remove approximately 80% of the material. They include large surface areas and several holes, providing the interface for inserting components into the robot base. Previously, Little Enterprises North needed multiple operations to complete the part on several vertical machining centers to reach all the holes. Now, the company can produce it on one larger five-axis machine, cutting machining time by 50% to perform the job in one setup.

“The part has a complex surface with multiple and variable radii that need to blend together,” Anastasio says. “Previously, it was taking us 12.5 hours using ball mills for the application, which included accessing deep pockets.” Now, using lens-shaped and tapered circle segment end mills as well as Hypermill, “Machining time has been reduced to six hours, and the surface finish is excellent.”

Meanwhile at Evans, owner Ken Evans grew interested in the promise of conical barrel cutting. After reading a metalworking industry magazine article about the process, Evans went to his programmers to see how they could take advantage of it to reduce cycle time and improve surface finishes when machining an aluminum box for a highly complex application. However, when the team first tried making tests cuts on an older machining center using CAM software that did not offer the right strategies or post-processing support for conical barrel cutting, the results were disappointing.

After researching the topic, the Evans team reached out to Open Mind a year later to help develop a proper process using Hypermill and Emuge-Franken circle segment cutters. With the knowledge base of the Open Mind support team to provide guidance, Evans found success with conical barrel cutting. Since that time, Hypermill has been the go-to CAM at Evans for five-axis applications.

An example of this success is found in one of the more complex parts produced by Evans. It starts from a 7,000 pound billet and is machined down to 450 pounds. “Using a large DMG five-axis machine with the efficient strategies and tool paths from Hypermill, we were able to reduce the machining time to approximately 13 hours per part compared with 23 hours per part when using an older machine and different software,” Golomb says.

Making Parts With a Little Help From Our Friends

Under the MMG umbrella, both Anastasio and Golomb agree that synchronizing knowledge and sharing projects has enabled the two shops to maximize efficiency for the MMG organization and its customers. When a new job comes in, Little Enterprises North and Evans evaluate the type of work to see which facility can best handle the work based on familiarity and experience with the type of part. “We communicate daily,” Anastasio says. “We have become a melting pot for processing, which promotes best practices,” adds Golomb.

With both Little Enterprises North and Evans using Hypermill, the two companies have a clear understanding of the capabilities of their sibling shop, making this collaboration even easier. “We also create a lot of additional capacity by moving parts from one facility to another with the opportunity to share expertise and re-program legacy parts in Hypermill,” Anastasio says. He adds that by moving these legacy parts into Hypermill, the companies regularly save on both programming and machining time. “The overall programming process is very user-friendly, and I know how far off-center I can be and yet still be within the travel of the machine. I would estimate I save 30 to 40% of programming time on the front end and realize significant cycle time reductions, yielding much better parts,” he says. “We are shedding cycle time and creating capacity for more orders down the road.”

Both Evans and Little Enterprises North plan to keep the keep the synergistic approach for taking on new jobs, supported by MMG. By working together under the same umbrella, the sense of competition felt by most machine shops has vanished, and both companies are flourishing by sharing their knowledge and experience.