Our ship had a hull made of Duron, coated in fiberglass. The Duron was fitted together with press fit mortise joints sealed on the interior by hot glue and silicone caulk and hot glue and on the exterior by epoxy. The hull was completely enclosed by the deck. Quick access to the interior or reset and kill switches could be done by opening the access hatch, or the entire deck could be removed for larger adjustments. It featured two motor driven jets for propulsion, which utilized differential steering and directional nozzles. We had the necessary fuel tank mounted 15in above the waterline which could be self-refilled by a pipe. The ship was also designed to have a lance which could fire water to tip over or fill funnels. It indicated team status and fuel status via an LED beacon. Foam tubes were used to create bumpers along the perimeter water line and the prow of the ship.
The deck of the ship was the mounting point for the lance, gun (the lance support frame) self-refill pipe, fuel tank, XBee, access hatch, and master switches. The entire deck could be lifted off by removing the wingnuts along the perimeter and all electrical components mounted could be disconnected from the control box. The lance and refill pipes could not be disconnected, though it would have been a nice feature. Sealant of all joints and holes on the deck was done using hot glue.
The deck was sealed to the hull with a neoprene gasket which ran along the hull edge and was sandwiched between this edge and the deck when all wingnuts were tightened. Washers were added under the wingnuts to distribute the load better and prevent damage to the deck paint. Care was taken not to over-tighten the wingnuts or leave them tightened and rick over compressing the gasket. After the competition the gasket was seen to be permeated with water though it did not noticeably let water in. Silicone rubber may have been a better gasket material as it is non-permeable.
The beacon featured two weatherproof LED strips to indicate team color and fuel status. Overhangs were added to shade the LEDs and keep them visible from 30ft away in the sun and further limit water exposure.
The access hatch was the upper portion of a resealable container by Sistema® from the container store, chosen for its O-ring and latches. Mounted immediately inside was a small panel with the master On/Off switch, motor On/Off switch, and reset button for the TIVA. These were placed so they could be easily and quickly reached.
The fuel tank and fuel level sensor were mounted as specified and the refill tube was routed through PVC and mounted on the same 3D printed part used so mount the lance (hidden). a tube was attached to the base of the fuel tank to help direct water off our deck.
The beacon featured two weatherproof LED strips to indicate team color and fuel status. Overhangs were added to shade the LEDs and keep them visible from 30ft away in the sun and further limit water exposure.
The access hatch was the upper portion of a resealable container by Sistema® from the container store, chosen for its O-ring and latches. Mounted immediately inside was a small panel with the master On/Off switch, motor On/Off switch, and reset button for the TIVA. These were placed so they could be easily and quickly reached.
The fuel tank and fuel level sensor were mounted as specified and the refill tube was routed through PVC and mounted on the same 3D printed part used so mount the lance (hidden). a tube was attached to the base of the fuel tank to help direct water off our deck.
The interior of the ship primarily housed the systems electronics. The jets were mounted at the base due to their intake design which also kept them below the waterline and therefore more efficient at thrusting. Reverse propulsion was performed by simply running the motors in reverse. Since they are jets this was not very effective or efficient but it provided some additional maneuverability. Maneuvering nozzles were controlled using a standard servo and push rod system, sealed with a rubber bellows gasket. In addition to the pump used for self/lance water (solenoids were used to choose self or lance), a pump was included purely for cooling the engine motors. a separate pump was used since the motor coolant coils were so small in diameter and we didn't want them to throttle the water which could come out of our lance. The motor coolant outlet was mounted to expel water just above our bumper. The couplers between the thrust motors and the impellers were such that they could be tightened, though this area sprayed some water during operation and had to be covered by paper towels during extended operation.
All control electronics (except for the Electronic Speed Controllers, ESCs) were housed in a watertight container (again by Sistema®). Various kinds of connectors were used to connect to control electronics and batteries, though it's worth noting that these connectors were not watertight and a potential weak point.
Sealant of the interior was done with silicone caulk or hot glue depending on the application and available time for drying. Mounting was done with hot glue (solenoids, servo) velcro (control electronics box, batteries), or foam tape (ESCs).
All control electronics (except for the Electronic Speed Controllers, ESCs) were housed in a watertight container (again by Sistema®). Various kinds of connectors were used to connect to control electronics and batteries, though it's worth noting that these connectors were not watertight and a potential weak point.
Sealant of the interior was done with silicone caulk or hot glue depending on the application and available time for drying. Mounting was done with hot glue (solenoids, servo) velcro (control electronics box, batteries), or foam tape (ESCs).