Deefholt Dynamics – SLM Aluminum Cooling Sleeves

What is your project about?

Deefholt Dynamics e.V. is a Formula Student racing team from Diepholz, Germany. For our upcoming season, we are developing a new electric race car with a major technical change: the first-time use of in-wheel (hub) motors in our vehicle concept.

In-wheel motors offer significant advantages in terms of packaging, drivetrain efficiency, and vehicle dynamics. However, they also introduce new challenges—especially regarding thermal management, as the motors are directly exposed to high loads and limited cooling space.

To address this, we designed and developed a custom aluminum cooling sleeve, which is mounted directly around the in-wheel motor and actively removes heat during operation.

Why did you decide to make it?

The decision to use in-wheel motors required us to completely rethink our cooling concept. Unlike conventional drivetrain layouts, hub motors cannot rely on centralized cooling systems and are subject to high thermal stress during acceleration, endurance runs, and hot ambient conditions.

Commercial cooling solutions were either:

• Not optimized for our specific motor geometry
• Too heavy or bulky
• Insufficient for the thermal loads expected in Formula Student competitions

Therefore, we decided to develop our own cooling system, centered around additively manufactured cooling sleeves, specifically tailored to our motors and vehicle architecture.

This project allows us to ensure reliability, efficiency, and performance, while giving our team valuable experience in thermal design and advanced manufacturing.

How does it work?

The cooling sleeve is designed as a lightweight aluminum component manufactured using Selective Laser Melting (SLM). This process enables us to integrate complex internal cooling channels that would not be possible with conventional machining.

Key features of the cooling sleeve include:

• Direct contact with the motor housing for efficient heat transfer
• Internal coolant channels optimized for uniform cooling
• Geometry specifically designed for additive manufacturing
• Defined machining allowances for post-processing and precise fitting

Coolant flows through the internal channels, absorbs heat from the motor during operation, and is then transported to the vehicle’s cooling circuit, ensuring stable motor temperatures even under high loads.

Images of the cooling sleeve, CAD design, and its integration into our race car are attached. Additional videos show the vehicle concept and development process.

Why PCBWay is important for this project?

Manufacturing this cooling sleeve requires high precision and reliable metal 3D printing quality. PCBWay’s experience in SLM aluminum manufacturing allows us to prototype and test this critical component efficiently.

PCBWay’s support enables us to:

• Validate our cooling concept under real-world conditions
• Iterate the design quickly if improvements are needed
• Ensure consistent quality for a safety- and performance-critical part

As a student team working with limited resources, professional manufacturing support is essential for the success of this project.

Looking forward

The cooling sleeve represents a key innovation in our vehicle concept and lays the foundation for reliable operation of our in-wheel motors. Successful implementation will allow us to further optimize performance and durability in future seasons.

We are excited about the opportunity to collaborate with PCBWay and demonstrate how advanced manufacturing technologies can support cutting-edge student engineering projects.