How professional 3D printing and carbon fibre-filled composites are helping to optimise racing performance.
Over several years, CRP USA and UVic Formula Racing have partnered to create many functional parts in carbon fibre-filled composite materials using the laser sintering 3D printing process. Made from CRP USA’s specifically engineered Windform materials, these components are distinguished for their versatility, mechanical properties and durability. One of the latest examples of the enhanced mechanical properties of such components comes from the world of Formula SAE, a student competition managed by SAE International (formerly known as the Society of Automotive Engineers).
The partnership between CRP USA and UVic has seen the manufacturing of several components, including the steering wheel and elements of the engine lubrication system, which have become integral parts of the team’s racing car. Luke Wooldridge, Powertrain Lead of UVic Formula Racing from the University of Victoria, says: “Like every year, the industry judges at the competition were very interested in the parts that CRP USA 3D printed for our racing car.”
He continues, “Carbon fibre-filled composites have become a core element of our car’s construction since we began our partnership with CRP. In our current car, Windform is utilised in all of our major systems, from our driver controls to the aerodynamics in our powertrain. The carbon filled composites provide an amazing strength-to-weight ration which is a critical property for any automotive project, but even more so in Formula SAE where every gram counts.”
OIL AND WATER CATCH CANS
The team designed new oil and water catch cans which were designed to integrate better with the car’s chassis packaging. These components were made from Windform SP, one of the carbon fibre-filled composites from CRP USA’s Windform range of 3D printing materials. According to Wooldridge, the Windform SP held up especially well to the high heat of the overflowing oil and coolant: “No significant damage was noted to either modules with water coolant temperature reaching ~125°C and the oil reaching ~150°C.”
“Although the importance of weight savings shouldn’t be understated, carbon filled composites give our team something even more important – the freedom to design and prototype without the restriction of conventional machining or the cost of expensive tooling,” he adds. “All of the designs which we have manufactured through our partnership with CRP have contained intricate geometries, thin shells or complicated lofted surfaces which have made them prohibitively difficult or expensive to create otherwise.”
This year, the team had a new faceplate made for their steering wheel for use with improved driver control switches. The part was made using Windform XT 2.0, another carbon fibre-filled composite from the Windform range.
“Windform XT 2.0 provided a better finished part as none of the in-house prints we made could provide the resistance to heat, impact, and direct sunlight needed from the part,” says Wooldridge. “In our controls system, CRP USA has helped immensely with the steering wheel and it has become a centrepiece of our car, especially at showcases where we can pass around the wheel and give everyone a hands-on experience.”
The main body of the steering wheel is made from Windform XT 2.0, while the hand grips were manufactured from Windform RL, a thermoplastic elastomer from the Windform range.
CURRENT CAR COMPONENTS
Continuing in the powertrain system of the car, CRP USA has previously help the UVic team to develop numerous iterations of their oil pan over the past few years, each made from Windform SP due to its impact and high temperature resistance.
“The flexibility in the manufacturing process has allowed us to design a reduction in the overall height of the oil pan and incorporate anti-sloshing features such as one-way baffle doors directly into the print,” explains Wooldridge. Reducing the overall height allows the team to drop the engine’s position in the chassis, lowering the weight distribution of the car and improving on-track, dynamic performance.
In addition, CRP USA also 3D printed a custom oil pick-up to go with the oil pan design, once again made from Windform SP. UVic Formula Racing’s aerodynamics system also uses front wing inserts 3D printed in Windform XT 2.0. These inserts act as a transition from the central wing element to the two outer ones while providing the attachment points for the front wing onto the chassis.
“It is in the area of design freedom in which CRP’s Windform composite materials excel particularly,” Wooldridge adds. “The range of material characteristics available through CRP removes even more design restrictions, pushing our team to constantly re-evaluate which parts we consider for re-design. For our project, the combined impact and thermal resistance provided by Windform SP allowed us to use a fully carbon filled composite oil pan which we would have never considered with other available composites. Within the Windform line of composite materials, the variety of the available products means that we always have a material that is suitable to our design, such as Windform RL thermoplastic elastomer which we used as custom ergonomic grips for our steering wheel. On top of all that, CRP has exceptional print resolution and quality which has allowed us to keep the overall size of our design to a minimum and eliminate post-machining.”
A ROBUST INTAKE
The intake the UVic team ran was manufactured through CRP USA out of Windform XT 2.0 back in 2019. The intake has held up incredibly well since then, Wooldridge says, lasting the team four seasons: “During our competition, we had engine clock temperatures reach up to 125°C and we experienced no warping or deformation at the mating surface between the cylinder head and intake. This thermal stability is critical to the reliability of our car as any deformation at this surface could lead to a catastrophic intake lead which would put us out of the race.”
The UVic team recently redesigned the intake to be larger and have a more optimised geometry for airflow into the engine, using the Windform XT 2.0 composite. Discussing some of the engineering characteristics of the new design, Wooldridge adds: “Thanks to the manufacturing capabilities of CRP USA, we were able to increase the overall size drastically, from a volume of 1.4 litres to 4.24 litres, while still having the print resolution necessary to print sealing surfaces and sensor mounting directly into our intake without the need for post-machining. The larger intake allowed us to transition from bent to straight intake runners improving the simulated efficiency of our air flow by 100%.”
The team plans to have the new intake up and running within the next few weeks.
“The durability of all the components 3D printed by CRP USA is incredible,” Wooldridge says. “In all honesty, we ask a lot of these parts when we are out on the track, and they continue to deliver. For example, this year, during testing, we struck a traffic cone hard enough to shear off the screw attaching the front wing to the chassis and bend our aluminium mounting arm without damaging the wind insert in Windform XT 2.0 attached to the other side.”