The thruster assembly was designed to enable servo controlled azimuthing while supporting two Blue Robotics T200 thrusters per pod to provide increased thrust and maneuverability. The assembly incorporates a concentric shaft arrangement, in which an inner rotating shaft transmits servo-driven motion within an outer structural housing.
Thrust bearings were integrated to provide low-friction rotation and reduce wear between the shafts under load, while washdown collars were used to secure the assembly and limit axial movement. This configuration enables precise angular control of the thruster pair while maintaining structural robustness and reliability under sustained thrust loading.
Material selection was driven by functional requirements at each subsystem level. TPU was specified for the pontoons to replicate the compliant, "squishy" behavior characteristic of the air-filled floats on the full-scale Minion platform. In contrast, PETG was utilized for propulsion pods to deliver higher structural stiffness and minimize deformation under the mechanical loads generated by the thruster assemblies during operation.
The construction began with precision cutting of foam insulation boards. Using dimensions extracted from the CAD model, templates were created to ensure accurate sizing before the boards were carefully glued together. Following the curing and drying period, each assembly underwent fit testing and light sanding to achieve optimal placement.
Once fully cured, the foam inserts were positioned into the pontoon's back piece. The remaining components were then sequentially installed over the foam boards, with each piece being glued in place. To ensure proper adhesion, a ratchet strap was applied to compress the assembly during curing. After the outer shell had fully set, a putty-like epoxy was meticulously applied to all seams, eliminating any remaining gaps.
The finishing process involved applying a coat of Bondo to the entire outer shell, which was then sanded smooth to remove 3D printing artifacts such as layer lines. Multiple coats of primer and spray paint were applied to achieve a uniform, professional appearance. As a final protective measure, each pod and pontoon received a generous coating of silicone conformal coating, providing UV protection and ensuring a complete waterproof seal for long-term outdoor durability.
