Custom Blade Manufacturing: The Mejzlik–NINANO Collaboration

Mid-2022 brought us an inquiry from Geon-Hong Kim, who runs NINANO, a UAV company based in South Korea. This isn’t just another drone manufacturer – they’ve earned recognition as one of the Top 10 companies in Asia at XTC, the world’s largest startup competition. NINANO develops unmanned aerial systems for smart logistics, military applications including reconnaissance and surveillance, and infrastructure inspection. The company approached us with a tailored propeller design and a clear idea of what they wanted to achieve. They just needed a partner to bring it to life.

What made this project particularly interesting was the division of responsibilities – while we usually manufacture the complete propeller assembly, NINANO would handle the hub production themselves and needed us specifically for producing the individual blades. We were eager to take on the challenge.

Project Requirements

NINANO needed a 30-inch three-blade propeller manufactured according to their design. They provided us with a complete 3D model, and our job was to develop the internal structure, create the production molds, prototype the components, and handle final production of the blades.

Their primary focus was maintaining the exact outer shape as designed and ensuring structural strength for operational performance. Beyond these two core requirements, NINANO didn’t impose additional constraints, giving us flexibility in our manufacturing approach.

Engineering and Manufacturing

Our engineering team began with critical material and construction decisions. We needed to determine what type of carbon fiber to use and whether to include a foam core inside the blades. After evaluating the options between PUR foam and machined foam cores, we selected PUR foam for the internal structure.

We also had to create the production molds specifically for this project. For the manufacturing approach, we used the wet layup method – a proven technique that gave us confidence in producing structurally sound, high-quality blades that would meet NINANO's performance requirements.

We identified that some minor design modifications would be needed for practical production. For example, the trailing edge in their original design was too thin to produce reliably. Addressing these design elements was essential for creating a viable final product.

Quality control followed our standard prototyping procedure. We produced initial blade samples and sectioned them into smaller pieces for internal inspection. By examining cross-sections of the prototypes, we could verify that all materials were properly bonded, the foam core maintained consistent structure throughout, and the overall build quality met our standards.

The project timeline from start to delivery was just over three months. Having a complete 3D model from NINANO streamlined the development phase compared to our typical custom propeller projects, which usually run around four months.

Project Challenges

The most significant challenge in this project stemmed from the division of responsibilities. Since NINANO was producing the hub separately, we had to create the root section of each blade with exceptional precision. Any deviation – even minor ones – could result in blades that were either too loose in the hub or wouldn’t fit at all.

We also needed to collaborate closely with NINANO’s team on design modifications to ensure the design could be produced effectively. When working from a customer’s 3D model, we typically need to communicate adjustments to optimize the root section design and sometimes incorporate customer-specific elements like logos, colors, or identification numbers.

These challenges were manageable thanks to NINANO's flexibility and responsiveness throughout the development process.

Practical Value and Customer Context

Our partnership enabled NINANO to achieve exactly what they needed – a precision-manufactured propeller that matched their aerodynamic design requirements. By handling the complex internal structure development and specialized production processes, we filled a critical gap in their technical execution capabilities without requiring them to build these competencies in-house.

By the time this case study was written, the propellers had not yet been deployed on NINANO’s commercial platforms. However, as CEO Geon-Hong Kim noted, several visitors to the company expressed “surprise and admiration for the innovative design and high-quality manufacturing” of the new components.

The collaboration also positioned NINANO strategically for their target markets. With their focus on defense applications and plans to offer UAV systems to military organizations in South Korea, the United States, and other territories, they needed components that would meet stringent government requirements. Our European manufacturing approach provided the supply chain advantages necessary for these strategic market opportunities, and their foresight in these decisions has proven beneficial as they've pursued international expansion.

„It was a great experience working with Mejzlik to develop our custom-designed propellers. Their extensive experience and expertise, including engineering services such as FEA, were instrumental in helping us achieve our performance goals. The final propellers met our expectations in terms of functionality and efficiency. However, the delivery timeline was slightly longer than anticipated.“

– Geon-Hong Kim, CEO of NINANO

The adjusted timeline reflected the level of precision and custom engineering involved, especially in adapting an externally developed 3D model and ensuring perfect hub fit without modifying the outer geometry. These factors required additional validation steps, which ultimately contributed to the final performance and reliability of the blades.

Future Collaboration and Outlook

Our relationship with NINANO has grown beyond the initial 30-inch propeller project. The next step was a 60-inch propeller system, which followed a similar process but required additional FEM analysis (Finite Element Method) to identify critical stress points and optimize the material composition based on NINANO’s operational requirements including load specifications and RPM data.

With additional projects in the pipeline, our partnership continues to develop. The working relationship has been exceptional from both technical and personal perspectives. Geon-Hong Kim and his team have shown great flexibility throughout our collaboration, and we’ve built genuine connections beyond just business – meeting at trade shows around the world and hosting visits at our Brno facilities.

This kind of collaborative approach creates the foundation for long-term innovation and mutual success.