Procedural Write-up

Waterwheel Design Project by Andy Mueller, Tufts University Engineering Fellow

5th grade Waterwheels

1st Waterwheel presentation (Completed in a single class period)

The multimedia Adobe Presenter presentation includes:
  • Who engineers are
    • Mechanical engineers (moving parts – Waterwheels!)
    • You don’t have to be an engineer to solve challenges
      • Engineering skills (the design process)
  • The Saugus Iron Works (SIW)
    • How the colonials used the waterwheels
  • Efficiency
    • Which waterwheel is more efficient (undershot vs. overshot)
  • Torque
    • How to calculate
    • How to make larger
    • Calculating with actual numbers
      • Lb-ft unit introduced
  • Assessment quiz

Waterwheel Design Project – Part 1

Waterwheel Testing Apparatus

Engineering Design Process

  • After seeing the first waterwheel presentation, students know F x R = Torque
  • Students design a waterwheel around this equation following the 8 design steps
    • Groups of ~4 split into designing:
      • Wheel (plates, bowls, Styrofoam, etc.)
      • Paddles (cups for example)
      • String – the waterwheel needs some way to wrap string around it while it turns, effectively lifting a load (see diagram)
    • Students create a design sheet listing the materials they will use, why they chose these materials, and how they will put it together
      • Make sure students are using diagrams to show how they will use materials
      • The design needs to be “signed off” by the head engineer before they can start building
  • Once their designs are signed off, building starts
    • Hot glue and masking tape are favorites for building

Competition – Round 1

  • See diagram for competition set up
  • Strongest waterwheel is determined by which can lift the heaviest load (most nuts or bolts)
  • Students take notes about how their waterwheel performed
    • How did it perform well?
    • How can it be improved?
  • After initial competition, students redesign (Design step #8)
    • Make notes on the design sheet as to what was changed and why
    • Change whatever needs to be redesigned on the wheels
    • Take pictures about changes – before and after for documentation (making a design portfolio?)

2nd Waterwheel Presentation

The multimedia Adobe Presenter presentation includes:
  • Estimation– an engineers best friend
    • Important for measuring the torque of waterwheels
    • Helpful for measuring:
      • Radius
      • Water in cups to determine force
  • Review of torque
    • How can estimation help us find torque?
  • Estimate
    • Radius
    • Force of water in the waterwheel
      • Volume of buckets
      • Total water in the waterwheel
  • Assessment quiz

Field trip

  • For students that we worked with, they were able to go to the SIW with worksheets that need to be filled out:
    • Find simple machines
    • Calculate torque of a waterwheel
    • Historical and science related questions
  • Obviously not everyone will be able to do this field trip. A field trip to any relevant location could be done in its place.

Competition – Round 2

  • At some point before the 2nd competition, have students:
    Student Waterwheel
    • Redraw design sheet
      • Show changes that are made and the reasons for these changes
    • Calculate torque of the waterwheel with “Waterwheel Worksheet
  • Students compete as before
  • As waterwheel testing is going on, have the students present how they estimated the torque of their waterwheel
  • Also have finished design sheet presented
  • Extension: A good extension of this project is to have students keep a design portfolio of their first and last designs, along with any work that led to the design or redesign of the wheels.