Water Wheelie

Students will design and print a custom water wheel that can operate for an uninterrupted 90 seconds.

Possible Standards
Next Generation Science Standards Grades 3-5 (Ages 8-11)

• Motion and Stability: 3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.
• Energy: 4-PS3-4. Apply scientific ideas to design, test, and refine a device that converts energy from one form to another.
• Engineering Design: 3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost. 3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem. 3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

Next Generation Science Standards Grades 6-8 (Ages 11-14)

• Engineering Design: MS-ETS1-1. Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.

Standards for Mathematical Practice
CCSS.MATH.PRACTICE.MP1: Make sense of problems and persevere in solving them.
CCSS.MATH.PRACTICE.MP2: Reason abstractly and quantitatively.
CCSS.MATH.PRACTICE.MP3: Construct viable arguments and critique the reasoning of others.
CCSS.MATH.PRACTICE.MP4: Model with mathematics.
CCSS.MATH.PRACTICE.MP5: Use appropriate tools strategically.
CCSS.MATH.PRACTICE.MP6: Attend to precision.
CCSS.MATH.PRACTICE.MP7: Look for and make use of structure.
CCSS.MATH.PRACTICE.MP8: Look for and express regularity in repeated reasoning.

Learning Objectives

• Students will design and print a custom water wheel that can operate for an uninterrupted 90 seconds.
• Students will use the design of a water wheel to learn about the engineering design process.
• Students will work in teams to generate an advertisement campaign that sells the best qualities of their design and product.
• Students will test their product and debrief about the results of the class.

Recommendations
Group Size: 2 to 3 students, depending on how many students are in the class, how many printers are available, and how much time can be allotted for the printing of the vehicles prior to judging and race day.

Class Size: up to 40 students

Materials Required

• At least one computer per group, loaded with SketchUp or Autodesk123D (For this particular lesson, SketchUp was a great tool with its naturally rigid design, allowing for defined endpoints in the water wheel model)
• Paper and pencil for drafting
• Airwolf 3D Printer
• Compass
• Ruler
• Protractors (recommended, not necessary)
• Super Glue to adhere the plastic pieces to any extra materials that are introduced
• Pitcher of water
• Bucket to catch water during testing
• Stopwatch
• 3/16” aluminum rods
• Water Wheel (SketchUp file)
• Water Wheel (STL file)

Introduction
Assumptions being made:

• students have a good understanding of 3D modeling. Prior to incorporating this lesson into a unit, it is recommended that students have had training on 3D design.
• Students have a good understanding of SAE (Imperial) and/or Metric units.
• Students have a good understanding of using a ruler.
• Students have a basic understanding of what a water wheel is and what it does.

The best overview of the water wheel is from the 30 second to 1 minute mark, but show however much would be necessary to adequately show students the purpose and function of a water wheel.

After the video:

Ask the class, “What questions do you have?” Writing every question on the board, or in a document of some sort, will be crucial. If a student has a question, it gets documented. What this allows students to do is think through their process and develop their own curiosity. Eventually, someone should ask how a water wheel works or what it is for. These two questions are vital to the success of the challenge and should be highlighted explicitly on whatever the instructor is using to note questions.

Once students have dried up their questions, ask “What could you do with this?” The same process follows, hoping to get students thinking about the value in a water wheel, especially in a time before we had fuel-powered machines. Essentially, students are validating an ancient means of power generation without having the depth of knowledge from a historical perspective. If it would be helpful, have students brush up on the history with this article. For a more kid-friendly version, this would be a better option.

Next, present students with their challenge:

Design and print a water wheel that can operate for 90 consecutive seconds without interference.

Using only paper, pencil, a straight edge, and a lot of imagination, have students design the 2-dimensional version of their water wheel. Encourage the use of online searches and hints to designing the most effective product within the constraints provided. However, students must be able to identify measurements for each component of their design (rather than simply drawing something that looks great but can’t be produced with a basic design platform).

The Meat
Within a 3D modeling program, groups will need to design their water wheel. While we recommend the dimensions be limited to fit within the constraints of a 1” deep x3”x5” rectangular prism, it is clearly open to whatever you would like your students to stay within. Keeping it under these constraints reduces the amount of material used and time needed to print out a sample.

Something else to consider is printing time and variability in density. For the thicker prints, it is recommended to have a 15% fill, unless a hollow print will suffice without compromising the fidelity of the structure.

Finally, all student designs should have a 3/16” cylindrical opening to allow for the axle in which the water wheel will be spinning on.

Prior to printing, groups must show their design to at least 2 other groups and have them confirm dimensions and review the plane’s components for any possible issues that may arise. Once this has been done, groups will send their final .STL file to the instructor and prepare for printing.

Some links to share with your students about their design:

The physics (and history) of a water wheel
Images of water wheels

When printing, it is advisable to print at least 3 perimeter layers thick, so take this into consideration during the design. Nobody wants to have a water mill that falls apart.

After the design has been printed, students will clean it up and verify all measurements for accuracy with a ruler and a protractor.

Testing Day
Set up a testing environment of 2-3 stations, each with a stopwatch, a bucket, a rod, and a pitcher of water. Have students run trials on their designs, timing each other to see how long each group’s water wheel can sustain a regular flow of water. For added comparison, have every student note the design type and duration of sustainable water flow for each group that tests their design.

Discussion

• How did you come up with your design?
• What would you differently after seeing everyone else’s product?
• Does the weight distribution have any significance on a flowing wheel?
• Why were the more effective wheels more effective? What did they do differently?
• What could we do with these water wheels now that we know more about them?
• Is there a problem that we could fix or help with?
• Is there a use in today’s landscape for a water wheel?

Each one of these questions can provoke thoughtful responses that are rich in mathematical reasoning and a great part of the engineering design process.

Just like in a Research and Design lab for major companies, the feedback and reflection on these projects will be the best part. Give students an opportunity to talk within their group and among their classmates to seek advice on improvements. After completing their print, groups will then proceed to go through the following steps as if they were an advertising company during the time period of their water wheel:

• Photograph their product for their advertisement (if it is a static ad)
• Reflect on what went well and what they would improve on if they had a chance to print again
• Create a marketing plan to sell your product to a specific group of people or industry from that time period

For the advertisement, students have the option of their medium, as long as it conveys the message in a time-valued tone and style. Whether it is creating a website, video commercial, radio commercial, magazine ad, billboard, or many others, the key is to be creative in the area that the students are comfortable. During this portion of the project, students will need to work efficiently within a deadline provided by the instructor.

Following the creation, students will showcase their advertisement with the class. Students can vote on which one is the best to use as the model for the school.

Desired Outcomes
Students learn about the engineering design process and are able to see value in the historical relevance of water wheels as a pivotal piece of our ancestors’ evolution.

 

Content & Instruction Developed by:
John Stevens – Airwolf 3D STEM Consultant
Instructional Coach – Technology
Chaffey Joint Union High School District
CUE Rockstar Faculty & Organizer
Google Certified Teacher
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