Rules for the Rube Goldberg Project

Your machine must be started by pulling a string 10 to 20 centimeters with a force of 2 to 5 newtons.
The last act of your machine must be to pull a string 10 to 20 centimeters with a force of 2 to 5 newtons.
Your Rube Goldberg Machine must include at least 4 of the 6 simple machines.
Your Rube Goldberg Machine must have at least 10 steps.

A "step" consists of one part of the machine causing another part of the machine to move in a way that helps to complete the task of the machine. (Click here for a more complete explanation.)
Every machine will have the same first step: "Something pulls a string, which ..."
Every machine will have the same last step: "..., which pulls a string."

It is not necessary to give your machine a base or a frame; however, if your machine does have one, the base and frame must not exceed the dimensions 0.70 m wide, 1.00 m tall, and 1.50 m long.
Your Rube Goldberg Machine must actually work. It does not matter how clever your design is if you are not able to make it work.
You will also produce a typed paper with a complete explanation of each step in your Rube Goldberg Machine.
You will be required to do some of the work on this project in class. After the initial planning day, you must bring all of the current parts of your machine with you to class on class work days.
Your completed Rube Goldberg Machine will be due a few days before spring break. (Your specific due date depends on your bell, see the Important Dates page.)
You may not use any part of the Mousetrap Game or any other pre-designed "crazy contraption" type game. (You may use parts from a Lego, Tinker Toy, or Erector set, or any other generic build-your-own toy.)
You must take your Rube Goldberg Machine and all of its parts off campus during Spring Break.
You must take your Rube Goldberg Machine and all of its parts off campus promptly after it is presented to the school.