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Mechanical Inventions

Play with kinetic and potential energy, making connections between how it is generated, stored, moved and can be transformed.

Learning Objectives

  • Identify and apply simple principles of movement to build mechanisms.
  • Play with kinetic and potential energy, making connections between how it is generated, stored, moved and can be transformed
  • Gain a better understanding of mechanisms and design by reverse-engineering existing inventions


45 minutes before starting the lesson

  • Create an example of the intended activity
  • Gather and prepare support materials


  • “What is a mechanism?”
  • “Do all mechanisms move? Why or why not?”
  • “What are the mechanisms around you? Have you used one recently, and if so, to do what?” Here are a few examples:
    • Lever – a pair of scissors
    • Wheel and axle – doorknob or an elevator lift
    • Pulley and belts – an escalator or conveyor belt at a grocery store
    • Inclined plane – a wheelchair ramp or road up a steep hill
    • Wedge – a doorstop or a shovel
    • Screw – hardware used for holding pieces of a bookshelf together
    • Gears – steering wheel of a car or foot pedals on a bicycle
  • “Why do we need mechanisms, what mechanical advantages can people gain?” For example:
    • To increase physical capabilities such as lifting or removing large amounts of concrete
    • To amplify or reduce a force, like when using levers
    • To use as tools in harsh environments to complete difficult repairs, like in outer space or when traveling deep under the ocean
    • To be precise, to be consistent throughout highly repetitive tasks, to do jobs in harsh environments that would otherwise be impossible or put humans in harm, and to not endure fatigue
  • “Can you combine mechanisms to become ‘compound mechanisms’? Can you think of an example?”
  • “Can a mechanism move on its own? How?”


  • Have your students brainstorm what kind of mechanisms and mechanical advantages they would like to build and test. Ask your students to come up with a goal for what the machine should be able to do, such as trapping a critter or grabbing something out of reach.
  • Students can work in small groups to create different mechanical inventions. Once completed, challenge students to combine all of their different machines into a single large classroom machine. For example, students could build a collaborative Rube Goldberg machine that transports a small ball from one end of the room to the other.


  • Design a mechanism that helps act out a story, such as shipping important supplies from your school to an uninhabitable environment for a deep-sea or space exploration mission.
  • Create an animated scene from a story using linkages on a flat surface. Add paper or cardboard to the construction pipes themselves to make moving animals or characters.
  • Interchange materials inside the machines, such as the pipe sizes to increase range of motion for linkages. For example, observe how a rectangular-shaped linkage can extend vs. a trapezoid-shaped linkage.
  • Create an original challenge and test solutions with other students, such as picking up differently-shaped objects like a cardboard tube or a rubber band.


You can have your students:

  • Switch individual mechanisms with other groups to test them out and get feedback for improvement.
  • Collaboratively test out the large classroom Rube Goldberg machine, iterating to design until the goal is accomplished! (ie, trapping a critter or grabbing something out of reach).


If applicable, create a spot to display each group’s creation. If the class combined their mechanisms into one large classroom machine, sit in an area that makes all parts of the machine as visible as possible for all students.

Ask your class:

  • “What other goals/challenges can you imagine for these machines? What else could these inventions do?”
  • Discuss these inventions/mechanisms as prototypes.
  • “If this/these machines were built to their full potential, how could they help people in your school? …in your community?”
  • “Did you reverse-engineer anything to build your machine? If so, what did you learn from doing so?”
  • “How can we continue to improve the classroom machine?”
  • “What challenges did you experience when combining all of these machines?”
  • “Are you a machine? What are the arguments for and against the assertion that humans are machines?”
  • “What other kinds of problems or obstacles do you think machines could help us solve?”

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