Mechanical Basketball

The ultimate objective of mechanical basketball, like most team sports, is to outscore your opponent. A round of mechanical basketball consists of a 30 second warm-up followed by 2 minutes in which two team members try to score as many points as possible using 2 marshmallows. Each team member uses a device that they have designed and constructed to throw the marshmallow through the basket, an act known as shooting. Different points are awarded based on where the marshmallow is when it is released. Here is a breakdown of scoring:

• 3 points are awarded for a successful shot from behind the three-point line.
• 2 points are awarded for a successful shot from anywhere inside the three-point line.
• 1 point is awarded for a successful shot from the free throw line.
• No shots are allowed from anywhere else inside the key.

Achievement

To meet the requirements of this challenge you must follow the steps in the design process.

1. Define the Problem

• Read these rules and
• write a summary of them in your engineer's notebook.
• Ask questions to clarify anything that you don't understand.

2. Generate Concepts

• Attend the class presentations and go on-line to find out everything you can about catapults and other throwing devices and document the results in your notebook.
• With your partner, brainstorm ideas, pick a possible solution.

3. Develop a Solution

• Sketch your design ideas in your engineer's noteboook.
• Decide what materials you will need and where you will get them.

4. Construct and Test a Prototype

• Obtain the needed materials, bringing them from home if needed.
• Design and construct one Mechanical Basketball Player (MBP) per team member.
• Take your MBP to the practice court and try it out.

5. Evaluate the Solution

• Enter your score on the leader board.
• Compare your scores with other team's scores.
• Adjust, calibrate, and mark the device to give consistently repeatable shots.
• Make changes and improve your MBP. Document all innovations, problems and solutions in your engineer's notebook.

6. Present Solution

• Provide a performance demonstration. Teams have 2 minutes to score as many points possible using 2 marshmallows. Team mates may rebound for each other.
• Retest as desired. Make sure all performance demonstrations for score are witnessed and signed in your engineer's notebook.
• Provide an Informational Report or Design Portfolio in the specified format on the last day of the challenge.

Constraints

This is a design and construction activity for teams of two students. Each team will design and construct two devices. The marshmallow may not be propelled by a launcher that is separate from the device. The energy source (rubber band) must be attached to the device. Four (4) rubber bands provided by the teacher are the only energy source to be used.

Each device may be constructed from any appropriate material in the technology laboratory and any materials brought from home that are not judged by the teacher to be inappropriate or unsafe. It must be small enough to fit inside the student's assigned locker when fully assembled.

The Court is marked with a 24" wide key, a foul shot line 30" from the backboard, and 3 point line about 48" from the center of the rim. The backboard is 12" wide and 7" high. The rim is about 14" high and has a diameter of about 4". [Scale is about 2" to 1ft.]

Criteria

Performance Demonstration (20 points)

Both team members will put their MBP on the court and each team member will be given a marshmallow. The team will be given a 30 second warm-up to adjust the position of their MBP. The team will then have 2 minutes to score as many points as possible. Team members may rebound for each other and may work together to maximize the number and accuracy of shots. The team must recover all errant marshmallows without help from other students or spectators.

Product — Mechanical Basketball Player (10 Points)

• An innovative, correct, detailed, and well-engineered solution that meets all design requirements.
• All detail requirements met.
• Designed to shoot the marshmallow consistently to the same spot.
• Well constructed to close tolerances. Accurately reflects plans and drawings.
• Light, efficient, and sound structure. Strong enough to stay together after repeated use.
• Finished (decorated) to be aesthetically pleasing.

Product — Engineer's Notebook (10 Points)

You should have an entry for each day. Make sure your notes include:

• A summary of the rules
• Sketches of your design ideas
• Problems that you encountered during construction
• Changes that you made to your design
• Results of any tests performed including points scored (page signed by an observer)
• The redesigns you did and retests.

Check that your notebook follows the guidelines

• Number every page sequentially (outside top) in a bound notebook.
• Designer (and witness if appropriate) sign and date each page.
• Date each entry. Label all figures and calculations.
• Draw a single line through mistakes and initial.
• Include annotated sketches to help reader understand the ideas.
• Give detailed explanations of how designs are supposed to work.
• Document all research.
• Chronicle problems encountered and your ideas to fix them.
• Provide technical drawings for prototypes and specify all materials.
• The information given in the entries is proportional to the amount of time given per class period.

Product — Informational Report or Design Portfolio (10 points)

See separate rubric

Tips, Hints, and Resources

• This is an engineering design challenge. Design an MBP that eliminates skill from the result.
• Some parts that you might want to have available include:
• Scrap wood
• Popsicle Sticks
• ⅛-in. axles such as Kelvin #390361 or #390349
• 4 marshmallows per day
• Rubber bands
• Eyelets
• Milk straws
• The bottom half of a glue bottle makes a great place to hold the marshmallow.

Last Updated 23 October 2012