Team Octane Racing and EOS Optimize Car Motor Cooling with AM

COEP Technological University | Success Story

Design freedom for complex internal geometries
Ensures high structural strength
The integrated design enhances heat absorption

At Team Octane Racing, we believe that engineering excellence is sintered layer by layer. With EOS's cutting-edge metal 3D printing, we crafted the perfect casing for our hub motors, bringing India's first FS race car with hub motors to life.

Piyush Goyal | Captain, Team Octane Racing

Team Octane Racing embarked on an ambitious project: building India's first Formula Student race car featuring dual hub-mounted Permanent Magnet Synchronous Motors (PMSM).

Traditional manufacturing methods proved incapable of producing the complex, integrated design required. This led the team to explore EOS Additive Manufacturing (AM).

The result was a groundbreaking, lightweight motor casing featuring integrated conformal cooling channels, manufactured using DMLS, which successfully managed thermal loads and enabled optimal, sustained motor performance.

The Client and the Project

Team Octane Racing is the official Formula Student team of COEP Technological University, Pune, India. Founded in 2010, the team has a rich history of designing and building F1-style race cars for prestigious national and international competitions like Formula Bharat and Formula Student Germany. They have experience constructing multiple internal combustion engine and electric vehicle race cars.

The project goal was to pioneer India's first Formula Student race car equipped with dual high-power density Permanent Magnet Synchronous Motors mounted directly in the wheel hubs. A critical part of this project involved designing and manufacturing a novel, custom housing for these motors that incorporated an effective cooling system.

These high-power density motors, combined with hot ambient conditions, presented a significant thermal management challenge. Generating substantial heat (requiring heat dissipation as high as 2.2kW), they needed an effective cooling solution within the wheel hub’s strict space constraints.

The Challenge

The primary technical requirement was to create a bespoke casing with effective thermal management for the new high-power density PMSM hub motors.

The motors generate significant heat, up to 2.2kW per motor, which needs to be dissipated. Unmanaged heat drastically reduces motor efficiency and performance and can lead to component failure, including insulation breakdown, bearing faults, winding damage, and magnet demagnetization. Therefore, effective cooling was paramount to maintaining peak performance and ensuring motor longevity.

Several design constraints complicated the task. The motor manufacturer specified a tight casing envelope: 90mm inner diameter, 120mm outer diameter, and 105mm length. Furthermore, space within the wheel assembly was extremely limited, prohibiting the addition of a separate cooling jacket outside the 120mm casing diameter. This necessitated the integration of the motor casing and an efficient cooling system, specifically a conformal cooling jacket, into a single, integrated component. The design needed to maximize both structural integrity and heat dissipation capabilities.

Traditional manufacturing techniques like machining or casting offered insufficient design freedom for the complex internal spiral cooling channels required. Integrating the casing and cooling jacket seamlessly was difficult, if not impossible, using these methods. Achieving the desired performance targets with traditional approaches would likely have resulted in a significantly heavier, larger component with poor material utilization (estimated 25-30%).

The Solution: EOS Additive Manufacturing

After extensive design iterations and feasibility studies, DMLS using an EOS M 290 was identified as the ideal manufacturing solution. DMLS provided the necessary design freedom for complex internal geometries, offered significant potential for weight reduction, and ensured high structural strength. An aluminium alloy, specifically EOS Aluminium AlF357, was selected due to its favorable thermal conductivity, strength-to-weight ratio, corrosion resistance, and machinability.

The team designed an innovative, integrated cylindrical casing incorporating internal, spiral conformal cooling channels. This integrated design maximized the contact surface area between the cooling channels and the heat-generating motor components, enhancing heat absorption. It inherently eliminated potential leakage points often associated with multi-part assemblies. AM enabled precise orientation of fluid inlets/outlets and mounting points for seamless integration within the complex wheel assembly. The final design resulted in a highly compact and simplified motor assembly.

EOS played a crucial role by providing expertise to optimize printing and post-processing parameters, such that the strength and ductility of the AlF357 process could surpass the wrought properties of 6061 grade of aluminium, as per international standards. The client could print and rigorously test sample parts to ensure the final components achieved zero porosity, a smooth surface finish, and mechanical strength comparable to billet aluminium grade of AA6061.

Crossing the Finish Line: The Results

The AM component achieved a remarkable heat dissipation rate. This superior cooling maintained the motor surface temperature below the critical threshold of 50°C, allowing the motors to operate at constant peak performance. The additively manufactured casing weighed only 1.3kg, effectively halving the estimated weight (at least 2.5kg) of a comparable traditionally machined component. Furthermore, the AM part successfully met all structural strength requirements, surpassing the properties of 6061 wrought aluminium grade (~300 MPa with ductility >10%). Additionally, EOS Aluminium F357 is proven to be a strong contender to replace AA6061 in demanding applications—offering not only comparable performance but also significantly greater design freedom compared to traditional manufacturing methods.

Beyond performance metrics, AM offered distinct design and manufacturing advantages. It allowed the successful integration of the motor casing and conformal cooling channels into a single, monolithic part. The team achieved highly complex internal and external geometry precisely tailored to the vehicle's specific packaging and performance needs. Material utilization was drastically improved to over 95%, a stark contrast to the estimated 25-30% for subtractive manufacturing. Ultimately, EOS AM technology directly enabled Team Octane Racing to achieve its ambitious goal of building India's first Formula Student car powered by dual hub motors.

The Future

EOS Additive Manufacturing technology proved indispensable for Team Octane Racing, providing the critical solution to overcome the complex design integration and manufacturing challenges associated with cooling their high-performance hub motors. The adoption of DMLS delivered tangible benefits: a fully integrated casing and cooling system, superior thermal management leading to sustained peak motor performance, significant weight reduction, and the realization of a complex design unachievable through conventional means. This project highlights the immense potential of AM for developing complex, lightweight, and thermally efficient components in demanding high-performance automotive applications and beyond. Notably, the resulting properties exceeded those of wrought aluminium 6061 in the T6 condition, highlighting the material and design advantages AM can unlock.