Page 22 - 3D Metal Printing Spring 2017

3D Caterpillar’s Grand AM Plan
Designed to minimize post-processing: a curved pipe section that serves as an air-handling part on the intake side of an engine-test rig. The Caterpillar AM factory team printed the pipe from 17-4 stainless steel on a 3D Systems ProX 300 machine SLM, without internal supports.
could expand beyond rapid prototyping,” DelVecchio explains. “We wanted to be a leader in the efforts to move AM into manu- facturing. This is game-changing technology—something Cater- pillar wants to be involved in. We are committed to staying on the leading edge of manufacturing technology, and the investment in AM fits that mission.”
Hence the launch of the AM factory, located in one of several buildings on the Caterpillar research and development campus in Mossville, IL. The AM movement is organized under several concurrent work streams: design for AM, printing of low-volume service parts, AM of prototypes and tooling, developing part- nerships, and fortifying the AM factory first as a laboratory for engineers to learn on production-capable equipment, and then as a mini production facility.
A Focus on Design for AM
To continue its mission to bring design engineers into the AM fold, in mid-2016 DelVecchio’s AM team developed a more targeted workshop. It was aimed at those Caterpillar design groups that appeared best-prepared to start focusing on design for AM, and take the next steps.
“We want them to get a better understanding of the parts
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and applications that provide the best opportunities to look at AM,” DelVecchio says. She understands the processes employed by design engineers, having worked mostly in component design for the company since 1989. “We want to give our engineers the tools they need to design for AM. We will coach them as needed, but they know their parts better than anyone.”
The team’s focus will be on complex designs, light- weighting opportunities and part consolidation (in part to eliminate leak paths). “While some people think of our end products as being really large equipment,” says DelVecchio, “I see all of the individual components. Part management is critical—we never want our customers to be concerned about our components.”
To help facilitate the knowledge gain needed to design for AM, in March of this year Caterpillar forged a part- nership with FIT AG, whose engineers are well-versed in the technology. The initial focus is on designing AM parts in titanium and aluminum. FIT, based in Germany and with U.S. offices in Boston, MA, has provided AM and rapid-prototyping services for more than 20 years.
“FIT has a lot of expertise in metal-AM design,” DelVec- chio continues. “Two of its engineers will work here with my team, initially on heat-exchanger applications. They also have extensive experience with engine-related appli- cations (through Formula One projects) that we can leverage. And, their medical-related expertise will help us better understand support structures.”
Design Competition Spawns
Metal-AM Production Project
Bringing Caterpillar designers and engineers into the AM movement took a big leap forward when DelVecchio and her AM team, early in 2016, launched a global, corporate-wide design-for-AM competition. The challenge was for the engineers to design a part (within their design control) for AM that could actually go into production. The winning design: a ball check valve, designed by an engineer in England working in the indus- trial power systems group.
The valve is used on a thermal-test rig used to evaluate ther- momechanical capabilities of engine components, which are thermally stressed to evaluate failure modes. The resulting AM part replaced a welded design that had several leak points. It’s less expensive to print than the fabricated assembly (of nine parts) that it replaced, and it functions better in service.
One key to the project’s success, accomplished through several design iterations with DelVecchio’s team, was the elimination of supports to avoid post-processing.
“Post processing can really be cost-prohibitive in AM,” DelVec- chio says, “and can otherwise take a good AM part out of the profitable category. That’s an ongoing focus here—to find ways to print parts with minimal supports, and being self-supporting was critical to the success of this part. The ball check valve is a