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Complex Machines for Simple Tasks!

This is an actual student built apparatus. The student determined that the purpose of this apparatus was to prepare a bowl of cereal for breakfast. It worked so well, that it was used by his family to prepare a bowl of Fruit Loops® for a period of time!

The purpose of this activity is to design a working apparatus made of various simple machines. It is used to perform a task. It is based on the ideas of Rube Goldberg®. Historically, Rube Goldberg® was a cartoonist who designed such machines to make fun of inventions. The Official Rube Goldberg Web Site explains the history behind this activity and also provides great background information about Rube Goldberg®.

Your job for the activity to create a "twenty" simple machine apparatus to perform any task that you wish. Ideas for tasks include the following: fold a napkin, fill the food dish for a pet, open a pop can, screw the lid on or off of a jar, turn on or off a light, turn the pages of a book, inflate a balloon, prepare a bowl of cereal, smash a grape, pour a drink into a cup, prepare a tossed salad, place toothpaste on a toothbrush, cook an egg, turn on or off a radio ... the list is only as short as you get permission from an adult to do!

Do NOT design an apparatus to throw objects, or do anything that could harm a person!



  • Your choice of materials. You might need to get permission from an adult to use some of the materials.
  • The materials may be very inexpensive if you use materials around the house.
    • Examples of materials include:
      • Wood
      • PVC pipe
      • Building toys like Legos®, Tinker Toys
    • Do NOT use a mouse trap or a rat trap!
Safety concerns: Be sure to keep all electrical, and heat safety rules. As with all science lab activities, the most important safety rule is to follow all teacher directions.


  1. Design your apparatus on paper as a "blueprint" before you begin building.
  2. Make sure that you identify each of your simple machines (such as levers) to make sure that you include the required twenty in the apparatus!
  3. Make sure that your apparatus is built with a solid base.
  4. Make sure your apparatus can fit through a doorway so that you can share it with your friends!
  5. Demonstrate your working apparatus to friends, family, or your teacher.
  6. Do NOT design an apparatus to launch objects or possibly harm a human or animal!
  7. Make sure that you clean up any mess that you or your apparatus creates! (Mom will be SO HAPPY!)
  8. Use as many simple machines as you possibly can.
When you drag your mouse over the link, a QuickTime sample video of an actual student built "twenty" simple machine apparatus will open in a new window. Close the window when you finish viewing the video to return to Sci-ber text.


  1. What was the easiest part of the apparatus to design?
  2. How many different simple machines did you use in the project?
  3. What task were you trying to do?
    • Were you successful in completing your task?

Review Science safetey rules here.

Get the plug-ins: Get Adobe Acrobat Reader , and Get Quicktime Player. (The QuickTime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

  1. The title of the activity
  2. The URL (Internet address)
  3. Your name.

Remember that no pictures can be used that show student faces or student names on it. 

Teachers should view the Teacher Site Map to relate Sci-ber text and the USOE 8th grade science core.

Updated October 24, 2008 by: Glen Westbroek

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