DiMora Motorcar Co. in January took another step toward producing its $2 million sport luxury sedan. By signing ProMetal RCT LLC, an Ex One company, as its latest technology partner, it secured a method for producing castings for the 1200-hp (895-kW) Volcano V16 engine that will power the Natalia SLS 2. An integrated product and process team will use the ProMetal digital 3-D printing technology to produce engine castings without the need for patterns or tooling.
ProMetal’s rapid casting technology (RCT) is an additive-manufacturing process that automatically builds sand molds and cores directly from CAD data. Bypassing the need for patterns, the print head builds layers of silica sand that are chemically bound for cohesion.
“These materials are exactly what some foundries use,” explained Dan Maas, Director of Business Development for ProMetal. “I like to emphasize that this is rapid manufacturing, since the alloys that are poured are exactly the same alloys currently used in foundry processes.”
The technology obviates the need for parting lines, draft angles, and undercuts, Maas said. “Design features used today [with this process] include nested cores, spiral vents, volute shapes, and integration of multiple components, in-situ cores, and unique rigging geometry to minimize turbulence.”
The DiMora program builds on the success ProMetal has had delivering three S-15 RCT machines to Ford Motor Co., which uses them to build prototype engines. The ProMetal S-15 machine delivers a maximum build envelope of 59 x 29 x 27 in (1499 x 737 x 686 mm) with a surface resolution of ±0.012 in (0.305 mm).
“Many times, we segment the casting to produce parts larger than we can print,” said Maas. He noted that the contents of an entire job box is produced in about 48 h.
While providing many advantages, the S-15 is currently a low-volume solution. Depending on the application, the break-even point for choosing RCT over a traditional patterned method is a volume of pieces in the hundreds. “Complexity really drives the break-even point,” said
The system seems to be a good fit for the Volcano engine. “This technology is at the forefront of digital additive manufacturing for the production of complex 3D shapes,” said DiMora Motorcar Founder Alfred DiMora. “During the design process, being able to accomplish in a few hours what used to take days allows you to refine your design through additional iterations. Eliminating patterns and tooling saves time and reduces waste, making the entire process faster, cheaper, and greener. The size of the casting boxes is another thing that attracted us to their technology.” DiMora noted that the company expects to build 75 Volcano engines for the Natalia program and an additional 100 engines for the boat and marine market.
The digital nature of ProMetal RCT’s process may be just as important as its other advantages. DiMora, the sole owner of DiMora Motorcar, intends to build a new automotive business model. ProMetal joins more than 50 technology partners that are sharing their technology with DiMora, both to help build the Natalia and expand their own development. The Natalia may only be the first car DiMora produces. Once it proves its basic technology, look for a mass-market car to follow, according to DiMora.
Digital data is a key enabler in this new business model. “[Digital design data] eliminates overhead and allows me to share quickly and easily with my partners,” said DiMora. “For example, I just send a CAD file to ProMetal and tell them to build it. We look at any problems over the Internet and over Skype. I am taking Silicon Valley, merging it with Detroit, and calling it the new Detroit.”
The company is two and a half years into a five-year development program for the Natalia. It expects to start dynamometer testing of the Volcano in about eight months. Simultaneously, the company will also test four engines on a track in test vehicles.