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Picture of Mechanical Cam Toys

GRADES 6 - 8, Social Studies, Science, Engineering

Lesson Overview

Cam toys (aka automata) use hand-powered mechanisms to create cyclical motions that animate a scene. Students design and create cam toy machines with moving objects/characters that symbolize abstract concepts and represent dynamic situations.

The lesson is structured to follow the Engineering Design Process (EDP), a process widely used by designers in any discipline to tackle challenges. While there are many ways that people solve problems, designers often opt to use the EDP because it offers a roadmap for the project journey and will help them work efficiently and effectively. The process requires that the designer first clearly Define the challenge, then Learn about and Explore existing solutions, before beginning the design stage. This understanding of the problem, combined with the Design step requirement of generating at least 3 different ideas, allows for a rich set of creative solutions to draw from in choosing a design direction. The designer is now ready to prototype the solution in the Create step. An important feature of the EDP is the expectation that the designer will build 2 or more prototypes after the direction is set. This is done by cycling through the Create and Observe/Improve steps a few times. It is recommended that students have an opportunity for at least 2 design-build-improve cycles. When students feel they have to “get it right the first time” they are less willing to take risks and be creative. On the second and later times through the cycle, they can fix flaws and adopt successful ideas from classmates. Hopefully, the designer will have an opportunity to Reflect on the product they created and the process they followed, looking for learning habits and insights that will help in future challenges. The Share step involves documentation, publishing, or presenting to affirm the project and inspire others.

Essential Question(s)

How can creating metaphors be used to increase understanding and enhance communication skills?

How can movement and imagery be used to create metaphors for social, scientific, and other academic concepts?

Skills Practiced:

  • Analysis and Abstract Modeling
  • Mechanical design
  • Engineering Design
  • 3D modeling in Tinkercad

Time Required: 3-4 Hours

Materials Needed:

  • Sketch paper
  • 3D printer and filament
  • Craft materials such as (cardstock, foam sheets, markers, hot glue)
  • Flexible PVC tubing, ¼” inside diameter
  • Wood dowels, ¼” diameter (optional, to reduced 3D printing time)

Step 1: Define


Creating physical objects can be an engaging and useful way for students to process their learning. Some physical models are directly representative of the academic content, such as a depiction of a sound wave, or a model of a cell. Abstract concepts, like a balance of power, ecological interactions, or societal changes, are also well-suited to modeling. Students practice higher order thinking skills when creating metaphors and symbols for abstract concepts. Coming up with imagery for social, scientific, or other academic concepts pushes the student to research the topic and develop a deeper understanding of it. The addition of motion, as in the Cam Toy activity, can make the project even more engaging and lead to creative, entertaining products.

Cams are rotating shapes that push on / rub against mechanical elements to create other motions. One rotating shaft can power many cams, and each can create a different motion in its associated mechanical element. Students decide which of these motions is best for the specific concepts they want to represent. In this project, students design the cams and moving objects in Tinkercad for fabrication on a 3D printer or laser cutter. Backgrounds or other static objects can be designed in Tinkercad and fabricated in a variety of ways for a more elaborate Cam Toy machine.

Challenge: Design and build a Cam Toy with motions and scenery that represent concepts related to the specified topic. Students may work in groups of 2 or 3. A Cam Toy base, rotating shaft, and a few cam designs are provided at this Tinkercad link. The base accommodates 2 motions. Students can modify the models to make smaller or larger machines.


  • Includes 2 characters/objects that move when the toy is operated. Possible motion types are:




  • Includes 1 static object that is a background, piece of scenery, or other objects.
  • The motions and scenery must represent concepts related to the specified topic.


  • The 2 motions must be different. The same type of motion can be used twice if the 2 motions differ either in frequency or magnitude. (For example, if there are 2 up-down motions 1 can have 2 rises/falls per cycle while the other has 1. For spinning, 1 can spin at a faster speed than the other.
  • The appearance and motions of the characters and objects must communicate the intended concept.

Student Product / Learning Goals

Students will choose motions that express physical or abstract concepts. They will design and build a working cam toy that expresses these concepts as a representative model or metaphor.

bekathwia made it!2 months ago
These were so much fun to make! We had them at the Autodesk booth at ISTE this year. Thank you for creating this guide! Here's a video: