When World Speed Record Holder Russ Wicks set his sights on producing a supercar like no other, he was determined to incorporate state-of-the-art automotive engineering and applied science materials with the latest advanced technologies available to produce a “road” car with unprecedented performance, style, safety, and efficiency. The result is not just a supercar, but a hypercar; the MOTION. Kepler Motors will produce only 50 MOTION hypercars, each hand-assembled.
From the beginning of the design process, the engineering team knew they would incorporate additive manufacturing for the production of low-run parts. However, what they discovered was additive manufacturing could be used to produce 3D printed patterns for investment casting. This capability prompted the engineering team to re-evaluate and re-design parts without traditional manufacturing limitations. Leveraging additive manufacturing technology allowed the team to create a cast titanium upright.
The engineering team sought out experts with Formula 1 and additive manufacturing technology know-how to assist with the cast titanium uprights. The team chose to work with the CRP Group.
Two specific divisions within CRP Group were placed on the project team: CRP USA and CRP Meccanica. CRP USA coordinated the project between Kepler, the various divisions within CRP Group, and the design consultants, leveraging their Formula 1 and additive manufacturing expertise. CRP Meccanica was selected for the project to provide cooperative design expertise for the uprights, as well as guidance on how to combine the use of additive manufacturing, rapid casting and precision CNC machining.
Designing without limitation
More designers, engineers and manufacturers are examining the potential of using additive manufacturing technology to 3D print parts for low-run production of parts.
“It is common for a company to rethink their design as soon as they understand the potential with 3D printing,” said Stewart Davis, Director of Operations, CRP USA. “Once an engineer understands the possibility of manufacturing highly complex designs and shapes using additive manufacturing technology and applications, shapes that could not be manufactured by traditional processes, they begin designing without limitations. By combining 3D printing, rapid casting and precision CNC machining, engineers can think outside of traditional manufacturing methods and design complex, intricate parts.”
To remove preconceived design elements, Kepler Motors Engineering Director Derk Hartland focused on designing the hypercar from the inside out.
The innovative MOTION has 800 horsepower from a unique dual powertrain. Power comes from 550 hp Twin-Turbo V6, driving the rear wheels while acting independently of two electric motors (totaling 250 hp) driving the front. The all-wheel-drive system launches the MOTION from 0 to 60 mph in under 2.5 seconds with a top speed of more than 200 mph. The car body is a carbon fiber composite monocoque chassis and body, F1 style double wishbone, and pushrod suspension with cast titanium uprights.
The cast titanium uprights are just one component that makes the hypercar unique. Because the suspension is exposed to all of the loads associated with cornering, down-force, braking and acceleration (which can occur in various combinations with each other), the uprights connect the wheel and half-shafts to the wishbones – one of the most complex and critical parts of the car. Multiple load scenarios were used with Finite Element Analysis (FEA) to ensure an optimal design that is strong, lightweight, and elegant.
Along with strength, weight is a critical aspect of (any) car’s suspension. In the case of the MOTION hypercar, the suspension performance is critical. The upright of the MOTION was designed to withstand the loads from all components effectively with minimum weight. The shape is complex as it secures multiple components.
“Lightweight, strength and durability are essential features for the hypercar to achieve its performance,” said Russ Wicks Founder Kepler Motors. “Cast titanium is top-of-the-line technology for this application, which for the Kepler MOTION was the only choice. Other cars use aluminum cast or billet, which delivers a bulky, weaker and heavier result.
“Typically, aluminum is used for the uprights and the material thickness is increased, which reduces the flexibility of the design,” continued Wicks. “Because of the increased material thickness, accuracy of the machining is critical to ensure correct position of components as well as complicated angles of machined faces. This makes CNC machining imperative, yet can restrict our design creativity. Working with CRP Meccanica allowed us to streamline the process. Using their laser sintering additive manufacturing technology to 3D print the pattern for casting the upright in titanium allowed us to design an optimal lightweight and strong part with no compromises. CRP Meccanica managed the entire production process – design to end part. They took the 3D printed upright patterns to the foundry, cast the upright patterns in titanium, precision CNC machined the titanium uprights, conducted the FEA analysis and inspected the final uprights. The results were better than we could have imagined.”
Kepler Motors
www.keplermotors.com
CRP Group
www.crp.eu
CRP USA
www.crp-usa.net
CRP Meccanica
www.crpmeccanica.eu
CRP Technology
www.crptechnology.eu
