Design and Construction of a Modular 3D-Printed Tandem Tilt-Wing Testbed

Tilt-wing aircraft are a promising eVTOL configuration due to their superior cruise efficiency potential. However, particularly during transitions, aero-propulsive interactions require flight testing for control law development and validation. Yet building suitable test platforms challenges academic programs, as conventional aerospace manufacturing requires resources and timelines beyond typical constraints, while the unique structural loads during tilt-wing transition and rotor failure scenarios remain poorly documented. This paper presents TANDEMIC, a 15 kg class demonstrator with 1.5 m wingspan, designed to address both challenges. We quantify critical flight loads across all regimes, including 3G envelope limits during transition, multiaxis propeller forces and moments, and worst-case fuselage torsion from rotor failures. The structural design employs a hybrid approach: CFRP spars and aluminum frames form the primary load path, while wing and fuselage aerostructures are fully fabricated on standard-sized desktop 3D printers. Using variable-density foamed ASA with temperature-controlled localized reinforcement, we achieve up to 54% weight reduction compared to our solid-printed baseline. A modular wing architecture with standardized interfaces enables future testing of alternative aerodynamic configurations, motor positions, and control surface layouts. Static testing validates the design, with all components sustaining ultimate loads at safety factors exceeding 1.5. Preliminary tethered hover tests confirm the aircraft’s flight readiness. This work provides a practical framework emphasizing accessibility and modularity, enabling other resource-constrained teams to replicate the approach.