Formal Progress Poster Update

The Final Solutions

Challenge 1: Signaling an Aircraft

            For the first challenge we have chosen solution number two, the use of a slingshot to propel a projective into a hoop. The device will operate on a single 3 wire servo. The projectile will be put into motion by the release of two elastic bands which were kept under tension until the unit needs to be used. The single servo will operate a blade which will cut the string, holding the elastic under tension

            The base of the structure will be one beam, 12 inches long, mounted onto the hull of the vessel at a 30 degree angle. Two 8 inch upright struts mounted perpendicularly will hold the beam in between them, six inches from the deck of the vessel. The elastic bands are attached at the top of the 8 inch struts, two inches above where they hold the beam. At the other end of the 12 inch beam where it meets the deck, a two inch strut will be mounted perpendicularly to the beam. From this strut, a 2 inch piece of twine will hold the elastic back 10 inches, parallel to the beam. The ball will be placed in front of the elastic, sitting on the beam.

            Next to this system will be the cutting mechanism. One blade of a scissor will sit underneath the string, perpendicular to it. The drive shaft of a 3 wire servo will move another blade in a 40 degree arc downward, meeting the fixed blade under the twine. This action will cut the string and release the tension in the elastic, projecting the ball from the vessel.

            This solution was chosen based primarily on how quickly it could accomplish its task and how simple the operation was. It consists of cutting only one string, and that will propel a projectile at a very quick speed. As opposed to the other solutions with design stood above in nearly every facet of selection.

Challenge 2 and 3: Towing a Stranded Vessel and Sinking an Enemy Vessel

            For challenge 2 we selected a hook sweeping downward, and for challenge3 we selected a hook sweeping upward. To reduce material use and motor capacity we have combined both of these actions into one ancillary unit. The hook will move both up and down, spanning a total of 110 degrees.

            The hook will be mounted horizontally on the side of the vessel with the 3 wire servo sitting on the hull. It will be capable of extending 80 degrees upward and 30 degrees below its parallel mark. This will ensure the hook can reach over the transom of the stranded vessel. It will also allow the hook to dip into the water and extend beneath the enemy vessel before it retracts upward in order to capsize it.

            The hook’s arm will be 8 inches long. The drive shaft of the servo will connect to the arm 2 inches from the end. A weight will be placed on the shorter side to help the hook rotate. On the end of the 6 inch side a two strut will be attached perpendicularly downward. This will help the hook anchor itself to the stranded vessel. On the opposite side facing up a .5 inch point will help it puncture when it is extended upward into the underside of the enemy vessel.

            This hook was chosen for both of these solutions because of their ability to be combined into one, the simplicity of their actions, and their chance of success. Neither one of these tasks is easy to accomplish. Using one unit for two solutions gives us an extra motor space for the controls of the vessel itself.

Challenge 4: Floating a Buoy

            For challenge 4 we selected the third solution, the use of a motor operated slide to drop the buoy off the side of the vessel. The slide will be titled down at an angle of 45 degrees. The buoy will travel down a grooved path in the slide and into the water. Before the buoy needs to be dropped, it will rest at an angle of 155 degrees upward to prevent any chance of the buoy sliding without the chute going down.

            The slide itself will be 8 inches long. The servo which controls the slides tilt will be attached 2 inches from the back, allowing the slide to tilt upwards and have the buoy rest against a fixed back piece mounted perpendicularly to the end of the chute. The slide will be on the stern of the vessel, mounted to the transom, amidships. The buoy will be dropped over the starboard bulkhead  

            We chose this solution because it was the simplest, and most material effective. The others would have been too complicated or used too many motor units. The slide also has a very high change of success as there are no complex moving parts, only one rotating servo.

Brainstorming

In the first week of school the VEX teams focused on discussing viable tasks and ways to accomplish these tasks. We were all kind of clueless to what this project completely entailed so we focused on understanding and discussing the things we would need to accomplish. We did some rough sketches of possible solutions to a few problems and took notes on things we thought would work. Looking back, I feel the brainstorming period was a great time to research and discuss ideas for our upcoming senior project.