This healthy looking workshop belongs to the TU Delft Formula Student team, one of the most successful teams in the history of the sport. Formula Student is a student engineering competition held annually in the UK. Students design, build, test and race a small-scale formula style racing car. It attracts teams from the world’s best technical universities. Judges often include ex team members from leading Formula 1 teams.
Nestled in the west of the Netherlands is a city called Delft, famous predominantly for two things: its hand-painted blue and white pottery and its world-class technical university. Founded in 1842 by Dutch King William II, the university has created some of the world’s leading engineers in various fields. These scholars include Astronaut Lodewijk van den Berg and former MIT Dean N. John Habraken.
The Three T’s of Success (Team, Task and Tweakability)
Delft’s Formula Student team has seen great success in recent years, winning two out of the last three Formula Student races. Taking the crown at the renowned Silverstone race track in 2014 and 2015, they’ve become the 3rd most successful team in Formula Student history. Chief Engineer Jonas credits their success to being aware of one’s specific role in the team:
“I’m in charge of the top level concept of the car, making sure every part of the car fits the core goal which is efficient motion.”
Using tools such as a lathe, mill, carbon fiber laminator and 3D printing, the Delft team completes the task of building an entire Formula-style racing car in only nine months. The key to success within such a short time is moving quickly while maintaining a versatile build. When challenges arise, things can be tweaked and changed without restarting the whole process. This is where 3D printing comes in crucial.
It All Starts with a Wheel
The first application of 3D printing used by Delft lies in the team’s steering wheel. Not only was it prototyped with 3D printing, but also for the end-part production. Having multiple drivers on the team meant they each have individual preferences while driving.
The biggest touch point in the car for drivers is a steering wheel, making it a hot topic of debate for the designers on how it should feel, grip and perform. The best way to solve the constant back-and-forth between the design team and drivers was to use the FDM 3D printing. This affordable and fast route let drivers specify exactly what they wanted without incurring large costs and delays given the short nine months timespan.
They used the 3D Hubs Student Program, a network of 3D printing services in over 100 countries, and got a short turnaround time at a reduced cost.
The Fused Deposition Modeling (FDM) works by extruding a reel of plastic through a heated nozzle which melts the plastic building layers. It then cools down and solidifies.
Jonas said, “a 3D printer doesn’t care as much about those geometry limitations. This meant we could iterate and test, iterate and test without worrying about the cost or delays.”
The process of creating the steering wheel began with a very rudimentary laser cut piece of wood with clay stacked on top of it. The drivers then pressed into the wheel with driving gloves on to create a rough outline and 3D scanned into the modeling software. During the modeling process, tehy wanted to cerate a steeering wheel that didn’t need supports so that it would print ina short amount of time. Those iterations could be churned out as drivers tested htem.
The three drivers testing the wheel used it very differently – some using under-grip, others using over-grip and. Creating a slightly awkward problem for the design team meant keeping drivers happy. The final production optimized hand grip all over the sides. Regardless of which driver was at the wheel, the steering would be suited to their needs. Jonas mentioned:
“The steering wheel is a narrow space and needs to be able to deal with lots of force. Drivers need to be able to really dig into the shape and apply force around the corners. It being strong and having a good grip instills confidence in the drivers.”
The Complex Bracket
A less visible part of the car also used the benefits of 3D printing, but for a much different reason than price or speed. Metal 3D printing, a more familiar technology in the automotive industry, was used to create an integral bracket which connected the steering rod of the inner wheel to the front of the vehicle.
The team made this part out of titanium using a process called direct metal laser sintering (DMLS). A mechanical arm spreads a thin layer of fine titanium powder down onto the print bed while a powerful carbon dioxide laser melts the powder and fuses the titanium together.
Due to the powder bed technology of the printer, the geometries that can be made can be extremely complex. Having a complete bed of powder sintered means the object doesn’t need complex support structures because it’s surrounded by poder. This is unlike FDM which is extruded, not sintered. Jonas explained:
“The reason we used titanium 3D printing for the part was that it simply couldn’t be made in any other way. We needed very specific geometries for the loads that were being applied.”
3D Printing Success
The Delft Formula Student Team has highlighted two different applications, which two different technologies to take advantage of the benefits they provide. As 3D printing becomes more accessible and continues to develop a greater range of materials, geometries and applications will become apparent in the automotive industry. Formula Student in the upcoming years is sure to be a hotbed of innovation and I’m excited to see how the cars develop alongside technologies available.
Contributing writer: George Fisher-Wilson, Communications Manager for 3D Hub
[All images courtesy of George Fisher-Wilson]