Coaxial gear box-The VTOL .

grabcad

Prior to modern quad drones and Arduino technology, VTOL aircraft utilized ducted fans which boasted greater endurance owing to combustion engines; however, they were quite noisy and easily detectable. Maneuverability was achieved through directional air flow. In a simplified design, I opted for split axis configuration to enhance visibility by eliminating the duct, with hopes of further advancements in the future.