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Is Hybrid Manufacturing Right for You?   Mark Langlois, Senior Editor

 
 



A new approach to manufacturing combines the design advantages of 3D printing with the quality and precision of multi-axis CNC machining.

Imperial Machine & Tool Co. (www.imperialmachine.com) has its feet firmly planted in CNC machining on American-made Haas equipment, and its future aimed at 3D printing. But company president Chris Joest is the first to say that CNC machining isn’t going anywhere.

Discovering the future of manufacturing is at the heart of the family-owned, 73-year-old shop. Joest’s son, Christian, is the fourth generation to work in the family business, and it’s his job to scout out emerging technologies. He’s currently working at the junction of 3D manufacturing and CNC machining, which helps explain why Chris Joest believes that hybrid manufacturing—a combination of CNC machining and 3D printing—will play an important role in the future production of parts and components.

“Every single metal structure that comes out of the printer needs to be machined,” said Chris Joest, 57, in an interview at his Columbia, New Jersey plant, near the Pennsylvania border. Although some firms find additive manufacturing disappointing for this reason, Joest said that those “extra” steps are Imperial’s specialty. And because most manufacturers of 3D printed metal parts need a machine shop to finish the job, they represent opportunity.

“We’re in the very early stages of 3D manufacturing as a country,” said Joest. “Here at Imperial, we’re looking at 3D printing as one step in the process.”

Joest is comfortable with that idea. A machined part goes through numerous steps before completion. In addition to being cut, milled, tapped, and drilled, it is often ground, bored, turned, planed, reamed, and polished. Why shouldn’t a 3D printed part require more work on its journey?

Joest argues that early adopters of additive manufacturing are realizing benefits today while other firms aren’t because they didn’t try. He said investing in 3D manufacturing today is costly, and it doesn’t mean profits will immediately follow. He estimates his additive manufacturing investment at nearly $2 million to date.

“We’re at the very beginning,” Joest said.

3D Printing with Various Materials
Perhaps it’s the end of the beginning, because depending on a customer’s requirements, Imperial already prints parts in titanium, aluminum, stainless steel, 4340 steel, cobalt-chromium, super alloys, and others using additive manufacturing. At the company’s affiliate, Imperial 3D Solutions, the company prints in various polymers.

“By marrying additive and subtractive approaches, as well as the American “can do” spirit, we can make America the leading force in manufacturing again,” Chris Joest said. “Meeting and embracing changes in manufacturing enables Imperial to continue our decades-long commitment to advanced manufacturing and the high-end careers it builds.”


Joest said that additive manufacturing and design have yet to catch up with each other, and the next generation of designers will imagine parts and products that no one has today.

“Additive manufacturing allows for a greater sense of creativity and expression in manufacturing than ever before,” according to a statement on Imperial’s website. “For folks like us, as well as the creative engineering community we serve, the possibilities are endless.” (imperialmachine.com/innovation.html)

Imperial recently printed 50 various-sized and shaped test pieces of stainless steel onto two test plates. The pieces were planned and printed larger than required to allow the pieces welded to the manufacturing plates to be cut off with a band saw and be ground to the required shape and size. An aerospace firm wants to check the quality of the 3D printed steel in a variety of tests, including shear, density, tensile, Charpy impact, and micro-structure.

Joest’s main point is that 3D manufacturing doesn’t stand alone. Even those simple blocks and rods must be machined to size.

New Possibilities
At Imperial Machine & Tool, additive manufacturing is another “work center” that’s treated like work centers for CNC machining, welding, or assembly, for example. “This allows us to bring the additive folks in on the entire manufacturing sequence before the items are even set up in the AM area, enabling us to foresee issues and complications and make allowances ahead of time,” Imperial states on its website. “It is common for us to build added holding, fixturing, and clamping areas on our AM builds to meet exactly those needs. All of this combined is a critical advantage to the process and what makes AM at Imperial such a natural fit.”

Post-printing work can include such obvious steps as removing the material used to attach the product to the manufacturing plate, removing supports, and removing powder that accumulates inside internal structures. For complicated parts, such as a manifold, tight tolerances and “unorthodox” internal geometry require post-production milling that is likely to mean machining to meet the tight tolerances and removing the powder. In many cases, the collaboration between additive personnel and CNC personnel starts at the design stage—as the part is first discussed—in order to accomplish those post-manufacture steps.

Designers may add structures to support the weight or add features to remove internal waste powder. They’ll add bulk to give the machinists something to cut. They’ll talk over design for internal geometry in patterns not possible using CNC machining alone, Joest said. This is all part of the combined approach that Joest calls Hybrid Manufacturing.


“Additive is a technology that is not driven by low cost (overseas) labor; rather, it is driven by technological benefits that can be realized right here, right now,” Chris Joest told D2P. “Companies that are in the forefront of their industry understand that offering new products—products that could not be created without an Additive/Hybrid Manufacturing approach—offers them the possibility to set themselves and their products apart from their competition. The reality with additive is that it must be married to subtractive capabilities (particularly with metal AM) in order to be effective. Our customers see that in Imperial, they have access to proven capabilities in multi-axis precision machined and fabricated components, as well as leading edge design options with our additive capabilities. The hybrid manufacturing approach required for most additive applications provides opportunities for close engagement between design and manufacturing functions.”

Two distinct manufacturing challenges drive additive manufacturing and CNC machining together, said Joest in a phone interview. “Metal 3D printers are not precise enough to meet the strict tolerances required,” he said. “The part cannot be made using CNC equipment due to the unorthodox internal geometry. The engineers realize the only way to make this manifold is through hybrid manufacturing.”

Imperial is also testing and producing 3D printed titanium parts for military applications. The company machines numerous titanium parts for a gun mount on the Chinook helicopter; it also machines structural supports and other titanium parts for the M777 Howitzer, a field artillery gun that saw service in Afghanistan. For this application, Imperial 3D prints titanium nuts that are as strong as the machined nuts they replaced. However, the internal structure of the 3D part is latticed so the replacement parts use less titanium and weigh less, a key attribute for a weapon carried by aircraft.

Multiple Machines
Imperial uses two SLM 280 HL 3D printers for titanium additive manufacturing in its Columbia, New Jersey headquarters. At the firm’s affiliate, Imperial 3D Solutions in East Stroudsburg, Pennsylvania, additive manufacturing machines include two Stratasys Dimension 1200es machines, two Stratasys uPrint SEs, and the Pegasus Touch SLA 3D printer from Full Spectrum Laser. In all, the affiliate employs 18 3D printing machines. Imperial 3D Solutions specializes in polymers, while Imperial Machine & Tool focuses on metal.

Joest believes the future of hybrid manufacturing isn’t going to be in a single machine that handles both additive manufacturing and CNC machining. He said that combination would create downtime for half the machine every time a part is worked, and no machining firm wants downtime on its equipment. A 3D printing machine next to a milling machine makes more sense for hybrid manufacturing, he said, because they can independently carry on without waiting for each other.

Imperial got its start during World War II, in 1943, from Joest’s grandfather, Michael Joest, who provided war material and machining for private firms. The business continued through Michael’s son, George Joest Sr. (the second generation), and Chris Joest (third generation). Now, as Christian G. Joest, the fourth generation, works on additive manufacturing and business development, the company remains committed to its U.S. roots.
 

“American manufacturing and our free market economy have been much beleaguered over recent decades,” Chris Joest said. “The focus has too often turned to low cost, and then an ‘offshore’ business model to achieve that low cost. This approach has cost the U.S. millions of high quality manufacturing jobs. With the advent of additive manufacturing, we have the opportunity to open up whole new manufacturing operations in the U.S.” Today, Imperial Machine & Tool Co. (imperialmachine.com) employs about 45 people, occupying a manufacturing plant of roughly 30,000 square feet. The company is ISO 9001:2008 certified.

“For over 70 years, my company, and our family, have focused on bringing high quality solutions to advanced manufacturing challenges to our customers,” Joest continued. “As such, we have always looked to employ motivated and talented individuals who are looking to make a career out of manufacturing. We don’t take our responsibility lightly, and, over the years, Imperial has provided high end employment for many hundreds of employees. We believe long term, steady employment is the backbone of American manufacturing. By offering our folks a career and not just a job, we enable them to focus on building and improving their skills throughout their lifetime.”

The firm’s customer base is roughly 50 percent military and 50 percent technology customers, including work for energy firms, semiconductor firms, and optics manufacturers. After serving the military through the early 1950s, the firm re-focused on the semiconductor business for the next 30 years or so. By the 1990s, the company shifted back toward military work, as well as continuing in the semiconductor business and expanding into optics and energy.

One complicated part that Imperial sells into the optics industry is a cooling manifold, which includes internal air and fluid channels that can only be manufactured using additive manufacturing. Joest said the customer accepted the additive manufacturing option without a problem.

Imperial uses additive manufacturing on some titanium parts and has provided 3D printed prototypes of these parts to the military, which is slowly transitioning from machined parts to additive parts, Joest said.

Joest said part of his job is to teach his customers the advantages of additive manufacturing. Early adopters are more likely to be private customers, rather than the military or government, he said.

Innovation in Manufacturing
“If it can help them make a semiconductor faster, they’ll try it,” Joest said. “In the military or the government, you have to convince the first person.”

One advantage that 3D manufacturing offers over machining is that it reduces the warehousing, inventory, and quality control steps. In 3D manufacturing, the manufacturer and customer focus on a single finished piece. In CNC machining, a single finished piece may be made up of a dozen parts or individual weldments for a multi-piece assembly. Each of the dozen pieces is part of the inventory. All that inventory must be kept and managed, an additional expense over an additive part. The machined part requires quality control steps for each individual component, and each weld must be x-rayed for quality control. For a single 3D printed part, all of the quality controls focus on the single part.

Simply put, 3D printing cuts inventory, quality control, and warehousing costs. And by integrating 3D metal printing into current multi-piece designs and assemblies, it can help reduce bill of material (BOM) items.

Fewer parts are easier and cheaper. One step in this process is to look for two pieces that are now machined separately and welded together to see if the two could be 3D printed as one piece. Each time such a situation is identified, the bill of material is reduced by one, the inventory is reduced by one, and quality control is reduced by one.

One example of a part at Imperial that may meet this criterion is a three-piece titanium weldment that is part of the Chinook gun mount. One part is a casting, the second is a tube, and the third is machined from solid titanium. The three parts are welded together.

“We buy the casting and machine it,” Joest said. “We buy the tube and machine it. We machine the solid titanium part. We weld them together and then we x-ray the welds.” He paused and said, “Or, we could print the part and do the final machining.”

Imperial printed it in titanium and presented the part to the customer for approval. But Joest isn’t expecting a response just yet.

“It’s very early in the game,” Joest said. Change takes time, despite the advantages. “Our customers don’t want to tip off their competitors about how much this process creates advantages. In this industry, it’s really being seen at their bottom line, and they don’t want to crow about it.”





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