Rapid Manufacturing of Lightweight Drone Frames Using Single-Tow Architected Composites

Technical Summary: Rapid Manufacturing of Lightweight Drone Frames Using Single-Tow Architected Composites

Problem Statement
The aerospace and robotics sectors face an increasing demand for lightweight, high-strength composite structures, particularly for optimized drone frames. Conventional composite manufacturing methods encounter significant limitations in this domain. They struggle to fabricate complex 3D architectures necessary for optimal weight savings and typically rely on assembling separate components. This assembly process introduces weak points at the joints, compromising structural integrity. Furthermore, maintaining continuous fiber reinforcement throughout complex geometries remains a persistent challenge, which limits the overall structural efficiency of the final product.

Methodology
To address these limitations, this study introduces a novel approach combining a specific structural topology with an advanced manufacturing technique:

• Structural Design: The authors conceptualize a drone frame utilizing a Face Centered Cubic (FFC) lattice structure. This topology is designed specifically for weight reduction and the realization of complex geometries.
• Manufacturing Process: The fabrication is achieved through 3D Fiber Tethering (3DFiT). This method employs continuous single-tow fiber to ensure precise fiber alignment throughout the structure.
• Key Innovation: Unlike traditional assembly, 3DFiT eliminates the need for joining separate components, thereby removing the weak points associated with conventional composite assembly while maintaining continuous fiber reinforcement.

Key Contributions

• Novel Fabrication Technique: The demonstration of 3DFiT as a scalable method for creating single-tow lattice truss-based structures.
• Integrated Design: The successful conceptualization and fabrication of a drone frame that integrates the FFC lattice topology directly with continuous fiber reinforcement.
• Performance Benchmarking: A comprehensive evaluation comparing the 3DFiT-fabricated frame against metals, thermoplastics, and other conventional 3D printing methods.

Results

• Mechanical Performance: Mechanical testing reveals that the fabricated drone frame achieves a high specific strength, reported to be approximately four to eight times greater than that of comparable metal and thermoplastic structures. It also outperforms other conventional 3D printing methods.
• Weight Reduction: The final drone frame weighs 260 g, which is 10% lighter than the commercial DJI F450 frame.
• Operational Impact: Flight testing confirms the frame's stability and durability under operational conditions. The weight reduction contributes to an extended flight time of three minutes compared to the baseline.

Significance
The paper claims that these findings demonstrate the potential of single-tow lattice truss-based drone frames as a viable solution for high-performance applications. By utilizing 3DFiT, the study establishes a manufacturing pathway that is both scalable and efficient, offering a method to produce complex, lightweight composite structures without the structural compromises inherent in traditional assembly-based approaches.