Projectile Launcher Project

Camelot needs your help!

King Arthur Pendragon is at war with Mordred and his army. Arthur has sent out messengers throughout the land to find the best siege engine to take out Mordred's stronghold and protect Camelot. Your mission is to design and then sell your launcher to the King for the defense of the Kingdom. Your siege engine must be sturdy and accurate; you must also present your design in a way that will grab the King's attention so that he chooses your design over the other competitors for the contract. Your project will be tested in class with a target that you place at your calculated range with points added for accuracy.

Objective:

You will plan and build a small-scale siege engine. At a minimum, your design must be able to hurl a marble. Additionally, you will be graded on your analyses of your design and design process.

Design Criteria:

The design must be your original design. You may not use a kit or use plans that are not your own. Your machine must be completely mechanical in design; the use of electricity, flammables, hydraulics, or compressed air is not allowed. The design must be freestanding and must fire without toppling. Parts may be used from commercial objects (toys, models, etc.) but the frame holding the device together must be constructed, not purchased whole. There are no limitations on the types of frame materials used in the construction of the device. You may not use any hazardous materials in your design. Non-compliance with any of these criteria will result in loss of project points and/or possible exclusion from the competition... which results in loss of more points… it’s a vicious cycle.

Brochure (45 points). The written portion of the grade includes presenting the following in a sales brochure format:

(5 points) A labeled illustration of the catapult - either one 3D drawing or two 2D drawings from different angles – showing the throwing arm, spring, protractor, base, etc.

(5 points each) each of the values for the quantities that are calculated with the accompanying explanations. These are:

·  the initial velocity, vo, at which the marble projectile fires (in m/s),

·  how far (in m) in theory the marble projectile will go horizontally, x

·  the maximum height (in m) of the marble projectile, y

·  the flight time of the projectile

(5 points each) Four graphs illustrating the motion of the projectile

·  position vs. time graph on the y axis

·  position vs. time graph on the x axis

·  velocity vs. time graph on the y axis

·  velocity vs. time graph on the x axis

Rubric

Requirement / Points Available
Salesmanship and Presentation / 10
Brochure (Including max. height, range, initial & final velocity, flight time, graphs) / 45
Calculations on separate paper / 20
Functionality (Does it work?) / 15
Accuracy (Did it hit the target?) / 10