Foundation Coalition: Active/Cooperative Learning

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Rubber Band Powered Car

A Freshman Engineering Design Project
Developed by P.K. Imbrie, Purdue University
(Developed while at Texas A&M University)

Instructions to Students

1.	Project Description As an engineer you may often be confronted with the development of a design concept in which you are given a specific set of unalterable specifications (or criteria) that must be meet (often referred to as design constraints). These constraints may take on the form of: 1) a limited budget; 2) having to use special materials because of a hostile environment; 3) geometry/shape and weight requirements; and the like. In order to investigate your ability to cope with a situation such as this, you have been provided a specific bill of materials, which is sufficient for you to construct a rubber band powered car. Your vehicle should be designed for optimal performance in the following areas: speed; distance; and power. To test the effectiveness of your final design, in the aforementioned categories, your vehicle will compete against all other vehicles in the class. The result of this competition will, in part, determine a portion of your grade on this project.
2.	Design Constraints 1. The materials (except fastening devices) provided to you are the *only* materials that may be used in the construction of your vehicle. For the purpose of this project, fastening devises are defined as "glue,� "tape,� and "staples.� 2. The vehicle must have a minimum of 3 wheels, all of which must support the total weight of the vehicle (both with and without cargo). 3. The vehicle must have an "engine" powered by rubber bands, which will be enclosed within the body of the vehicle. 4. The vehicle must start from a resting position and cannot otherwise be catapulted or slung into motion. Once released, the vehicle must operate without intervention. 5. The vehicle must have a cargo area capable of carrying an additional 500g mass that is roughly in the shape of a coke can (either standing upright or on its side). 6. Geometric constrains (not including the wheels) are: a. Minimum top view area is 75 in². b. Minimum projected back view surface area is 30 in²^c. Minimum projected side view surface area is 22.5 in². d. Minimum projected front view surface area is 7.5 in². e. Overall vehicle length 12 in. f. Overall vehicle width 5 in.
3.	Performance Measures Vehicle speed will be measured by a distance/time relationship where the distance is some predetermined perpendicular length from the start line. Maximum distance will be measured radially from the start line to the final resting point of the vehicle. Vehicle power will be estimated by attaching a sled (which has a known, but unspecified mass) to a hook on the back of the vehicle and measuring the distance the sled is displaced by the vehicle and the associated time. Where applicable, time will always be measured when the vehicle comes to a complete stop.
4.	Report Instructions This assignment is a final project report on your car development, testing, and conclusions. Please note that the audience for the report includes all of your instructors, including your English instructors. Therefore, your report should include all requested information and be written on a level that an educated but non-technical audience can understand. This may mean including an occasional definition or choosing to use a general rather than technical term where feasible. The Report Requirements come partially from engineering and partially from English. Please carefully check to make sure that your report fulfills all requirements.
5.	Project Deliverables Just to reiterate�each team must submit the following: One team-designed rubber band powered vehicle A team written report detailing the project

Lesson | Instruction to Students | Report Requirements

2002, P.K. Imbrie
These materials may be duplicated for educational purposes if properly credited.