Windform Composite 3D Printing Materials Enable Lightweight, Flexible Air Inlet

This article originally appeared on compositesworld.com.

Earlier this year, additive manufacturing provider CRP Technology (part of CRP Group) launched Windform RL, the first thermoplastic elastomer material within the Windform family of materials for professional 3D printing.

Now CRP’s R&D department has developed a new front air inlet for a Moto3 racing customer, which was prototyped and manufactured in Windform materials using a selective laser sintering (SLS) additive manufacturing technique.

According to CRP Technology, testing had shown that increasing air flow to the air-box improved the performance of the engine at every rpm range. This led the team as well as the engineers to conclude that they need to design a new track-ready inlet. This design would make the air inlet longer, and bring the opening up to the front side of the fairing, in order to have a direct air flow with less turbulence.

CRP wanted to avoid modifying the existing frame and the existing triple clamps. The design would have to fit to the existing platform in order to test the on-track advantages and disadvantages of using this solution, and to make a direct comparison with the current standard inlet.

Once a first draft of the air inlet was developed, a prototype was created in Windform GF 2.0, a composite material with a polyamide base filled with glass and aluminum. The decision to use Windform GF 2.0 was made to reduce costs, while being able to perform multiple tests with multiple prototypes.

The first prototype allowed engineers to see if the design fitment was correct and suitable for assembly. It was revealed by the first design that some sections needed to be changed due to the lack of space available under the lower triple clamp. This problem is further complicated when the bike is cornering and under braking conditions.

To optimize the volume of the inlet duct under the lower triple clamp, the engineers adopted a creative approach and decided to create a portion of the duct in Windform RL, a rubber-like composite material for 3D printing produced by CRP Technology. This would be bonded to the main structure that was made out of Windform XT 2.0 for evaluation in racing conditions. The engineers also carried out a bonding test to study the characteristics of the final assembly.

The concept was to make the bottom part of the duct with Windform RL in the fork and triple clamp area, and then assemble this into the top part produced in Windform XT 2.0. This approach would allow clear airflow on the straightaway sections of the course, and thus improve flow to the airbox. Under breaking, the front fender could move up and collapse the inlet duct without any damages, due to the flexible material.

The team and engineers eventually decided to change the inlet by reducing the portion that would make contact with the fender to reduce drag perceived by the rider. The part made in Windform RL was enlarged according to the second test, and engineers and the rest of the team could get the correct fit for performance.

In the final test version, Windform XT 2.0 was utilized in order to reduce the weight of the front and central part of the inlet, while the Windform RL material was used for the flexible part of the inlet. The two parts were bonded together after being produced.