RC boats are widely commercially available, while RC submarines remain a costly, niche product. Therefore, the objective of this project is to transform an off-the-shelf 1:18 scale RC boat into a submersible submarine capable of underwater and surface maneuverability, and can dive to a depth of at least three meters before reliably resurfacing. Some goals in this include developing a ballast system to resist hydrostatic pressure and achieve buoyancy, sealing electronics to ensure waterproofing at high depths, and underwater propulsion.
This project was divided into three primary subsystems: ballast system, waterproof hull structure, and propulsion and steering electronics. Our ballast system utilizes a syringe-based system that remotely adjusts the balance of air and water within the vessel via linear actuators. The volume of the syringe was calculated using Archimedes’ Principle to ensure the submarine can effectively overcome buoyant forces and achieve submersion. Most electronics are securely sealed within the interior of the hull to ensure waterproofing and reliability. Additionally, 3D printing was utilized to design custom components to simplify system integration, including a frame for mounting the syringes and linear actuators onto the boat .
Through multiple design iterations and testing, our team successfully produced a complete submarine prototype that incorporates a ballast system, waterproofing, mass distribution, and functional steering electronics. During our final pool testing, our prototype experienced two critical hardware failures. The propulsion system stopped responding due to an internal water-contact sensing circuit and one linear actuator in the piston mechanism failed due to high resistance caused by compressed air inside the chamber.