Formula SAE is a student design competition organized by SAE International (previously known as the Society of Automotive Engineers). The competition was started in 1978 and involves student teams from around the world. Each team designs, builds, tests and races a small-scale formula style racing car. The cars are then judged on a number of criteria such as design, fuel economy, acceleration, endurance etc.
For this year’s competition, Patrick Harder, a 4th year student of Automotive Engineering at the University of Applied Sciences in Berlin used a mix of Stratasys FDM® and PolyJet® 3D printing technologies to design a new airbox for this year’s competition which pits their car against about 500 other competing teams.
What we see here is a working model of what the Stratasys-Objet merger is all about: 2 complementary 3D printing technologies used together to create a hybrid functional prototype – that then becomes part of the final car.
The airbox, or air intake chamber plays a critical role in an engine’s performance. A well-designed airbox will draw air more efficiently and effectively into the engine and thus improve performance.
Stratasys ULTEM 9085 material (the gold colored thermoplastic material created on the FDM-based Fortus 3D Printer ) was used for the parts of the airbox where high temperature resistance (over 120°C/240°F) and vibration resistance are required. The ULTEM material was used for the manifolds, velocity stack (the trumpet shaped device that lets the air in to the engine) and throttle body bottom and top.
Meanwhile, the Digital ABS material (created in the PolyJet-based Objet Connex multi-material 3D Printer) was used for the plenum chamber - where the airbox requires a combination of toughness, unique geometry and high surface finish. This is where the airflow and air fuel mixing occurs.
And in addition, the team also used the PolyJet VeroClear transparent material to create the small oval windows we see on the sides of the airbox. This helps the team monitor the fuel mixture rate in the cylinders and ensure that excess fuel does not build up and get trapped in the intake manifold.
Many thanks to Patrick for the photos and video and to our very own Hannes Kalz, of the Stratasys Leader Benchmark Center in Germany who brought us this story.
We wish Patrick all success in his upcoming competitions! Go team Stratasys!