Peter Zelinski has been a writer and editor for Modern Machine Shop for more than a decade. One of the aspects of this work that he enjoys the most is visiting machining facilities to learn about the manufacturing technology, systems and strategies they have adopted, and the successes they’ve realized as a result. Pete earned his degree in mechanical engineering from the University of Cincinnati, and he first learned about machining by running and programming machine tools in a metalworking laboratory within GE Aircraft Engines. Follow Pete on Twitter at Z_Axis_MMS.
The parent company to RPM Innovations has been additively manufacturing metal parts this size for years on machines built in-house. The machines will now be manufactured and sold to others.
One of the constraints on additive manufacturing machines that make metal parts from powder has been the relatively small build envelope of these machines. Rapid City, South Dakota-based RPM Innovations is now prepared to challenge that constraint with laser deposition additive manufacturing machines that have a build envelope of 5 ×5 ×7 feet. An 83-inch-tall rocket-like part made from Inconel 625 that was grown in one of this company’s machines will be on display in the Advanced Manufacturing Center at IMTS.
Robert Mudge is president of RPM Innovations, which was spun off last year from contract manufacturing firm RPM & Associates, a company he also co-founded. The parent company has been applying laser-deposition additive manufacturing technology for 10 years. Growing interest in the technology combined with customer pressure for bigger parts led the company to build machines with part-making envelope of 5 × 5 × 7 feet. The success of these machines, and the application track record so far, gave RPM & Associates the confidence to now launch a separate company both to provide contract additive manufacturing services and to manufacture various models of this machine for other users.
The RPM machines use a blown-powder approach to applying the metal. Deposition rates reach 2 to 3 pounds per hour, which is fast for a powder-based additive machine. Small additive metal machines, such as powder bed machines, can achieve finer detail that what RPM can do, says Mr. Mudge, though thin walls and precise features are possible on RPM’s machines as well. By contrast, he says some of the strengths that make the blown-powder machine distinctive include the abilities to perform cladding on existing parts and to repair worn parts back to their new profile.
One other strength is the ease of recovery if there is a problem in the build, he says. A flaw in the build cycle with some metal additive manufacturing machines requires the entire part to be scrapped. With RPM’s machine, the part can be pulled out, machined down to where it is still good, then returned to the additive machine to resume the cycle.
Most of the additive manufacturing work previously done on RPM’s machines is covered by non-disclosure agreements, so Mr. Mudge can’t elaborate on these parts, but he says many would probably be surprised by the application history this technology has already seen. Nearly 80 percent of its applications have been related to aerospace or defense, including aircraft engine components and aircraft structural components for “companies whose names you’d recognize,” he says. Inconel 625, Inconel 718 and titanium 6-4 are among the alloys that the machines apply routinely.
The rocket-like part took around 340 hours to build is approximately 7,000 layers, he says. And to the RPM staff, that is not all that long. “We have had big parts—not as tall as this, but broader and a lot more complex—that took us 1,800 hours to build,” Mr. Mudge says.
At next week’s International Manufacturing Technology Show, Makino says it will demonstrate the broadest range of automation possibilities it has brought to any IMTS so far. Six different approaches to automation for unattended loading and unloading of machines will be operational in the company’s booth. Why so much attention to automation? Mark Rentschler, Makino’s head of marketing for the Americas, says automation is increasingly important to machining facilities for at least three reasons.
First is the skills gap. Among high-value manufacturers across all industries, finding qualified, skilled personnel is a challenge. This is perhaps the most obvious reason automation is in demand. However, a second factor is the ongoing move, also throughout various industries, toward higher-mix and shorter-leadtime production. The right automation system is an aid to rapidly shifting between part numbers, Mr. Rentschler says.
The third factor he cites is the increasing sophistication of North American manufacturers. Variables in a manufacturing process are sources of expense. Machine tool automation saves cost by eliminating variation in setup time (which otherwise would depend on the fluctuating pace of a human operator) and variation in machine utilization (which otherwise would be subject to the operator’s breaks and interruptions). This connection between variation and cost is something the largest manufacturers have long understood, but now a significant portion of smaller manufacturers appreciate this as well.
The different automation solutions shown in the booth will include well-known options such as robot loading and pallet systems for individual and multiple machines, plus options that are more unusual, such as:
A die/mold cell devised in conjunction with Erowa. The cell (shown) will include machines for graphite milling, hard steel milling, wire EDM and sinker EDM, all fed by a robot. Steel blocks enter this cell, and finished mold cores or cavities leave.
Five-axis automation. Because automated loading and unloading require automatic workholding able to repeatably clamp and position the work, five-axis machining is considered challenging to automate. The company’s a51nx-5XU machining center will be seen using a workholding device that is essentially an inverted 50-taper toolholder receiver. Workpieces mounted on this taper will be loaded into the machine by a device resembling a toolholder.
Aerospace automation. The company’s a61nx-5E machinining center will be automated with a multi-layer pallet pool applied in a context where it might not be expected. High-power, high-speed machines cutting aluminum aerospace workpieces achieve short cycle times that require workpieces to be delivered to the machine quickly. The demonstration will show how modern pallet-pool automation provides the speed to achieve this.
Makino’s free Lunch & Learn program also returns to IMTS this year. The company says it has doubled the space available for the lunches featuring presentations by successful manufacturers.
This batch of parts produced through direct metal laser sintering
was made by one example of an EOS user, C&A Tool.
At next month’s International Manufacturing Technology Show, various new developments reflect IMTS attendees’ heightened interest in additive manufacturing and the sizable number of exhibitors offering additive manufacturing services or technology. This category has now added its name to a pavilion: This year the North Hall will house the Fabricating/Laser/Additive Pavilion. In addition, a new event has been added to the show: the half-day Additive Manufacturing Workshop September 9.
One other significant additive manufacturing development is this: EOS, the maker of additive manufacturing machines for metal and plastic parts, has for the first time brought its North American User Day to IMTS. The recurring event that gathers together users of EOS laser-sintering technology will take place Wednesday, September 10, and is open to both EOS customers and IMTS attendees. Speakers will include Dr. Hans Langer, the company’s founder and CEO, as well as companies offering solutions related to additive manufacturing such as MicroTek Finishing, Shapeways and Within. To register or learn more about either the EOS North American User Day or the Additive Manufacturing Workshop, visit this page.
Cutting tool supplier Widia and manufacturing media firm Creative Technology produced this video titled “Why Not Me?” to illustrate manufacturing careers, and to highlight young people who have chosen this work as well as their employers and teachers. The video visits various sites where manufacturing is either performed or taught, including Cardinal Manufacturing, Chippewa Valley Technical College, MRS Machining and Prototype Solutions Group. Carlos Cardoso, chairman, president and CEO of Kennametal Inc. - Widia Product Group, appears in the video to make the case for the value and opportunity of manufacturing careers.
Gears are expensive parts to make in small quantities. This video from 3D Systems describes how just one gear—for an oil pump—was critical to overcoming a problem with excessive oil pressure in a Mitsubishi 4G63 race engine for a car run at over 185 mph.
English Racing of Camas, Washington, knew that a change in gear size might solve the problem, but the team didn’t know how to get this gear. The complex custom part would have been costly to machine as a one-off job, particularly since one-off prototypes would also be needed to test and refine the design.
Metal Technology of Albany, Oregon, proposed additive manufacturing instead, growing the part directly from the CAD model on its ProX 300 direct metal sintering machine. This video shows the part not only being additively manufactured in this way, but also functioning successfully at full speed within the engine.