STANDARDS

NGSS: Core Idea: PS3.C

CCSS: Reading Informational Text: 3

TEKS: Science: 3.2A, 4.2A, 5.2A, 6.2A, 3.6B, 4.6D, 5.6D, 6.8E; ELA: 3.13, 4.11, 5.11, 6.10

One Crazy Device

Who can build the most ridiculous step-by-step machine?

March 2017

By Kathryn Free

How does this machine turn on a light bulb?

(1) A boot kicks a bowling ball, (2) which knocks over a bowling pin. (3) The falling pin pulls a rope to open a birdcage. (4) The escaping bird bumps a ball down a track...

MAGICTORCH

...(5) The ball knocks over dominoes. (6) A domino falls into a truck, (7) which rolls down a seesaw...

MAGICTORCH

...(8) and knocks over a hammer. (9) The falling hammer turns on a toaster....

MAGICTORCH

...(10) The toast pops up and hits scissors, which cut a rope. (11) A weight falls onto one side of a balance. (12) The hand on the other side of the balance rises, flipping the light switch.

MAGICTORCH

A boot kicks a bowling ball, rolling it down a ramp. The ball knocks over a bowling pin, tugging a rope that swings open a birdcage. More objects bump, crash, and roll, one after another. Finally, a weight drops on a scale, lifting a hand that flips a light switch. Ta-da!

Sound complicated? That’s the point. This wacky device is a Rube Goldberg machine. That’s a contraption engineered to perform a simple task—like flipping a light switch—in a ridiculously complicated way. And every spring, thousands of students compete to build the best ones in Contests, held online and at sites around the country.

At Cornerstone Christian Academy in Willoughby, Ohio, two teams of middle school students enter the online contest every year. Seventh-grader Mia Cocca is on one of them. In 2016, her team built a machine that took 45 steps to open an umbrella! They carefully designed every step. “There are so many things you have to get right,” says Mia.

Rube Goldberg Competition

Watch a video about a prize-winning Rube Goldberg machine and how it works.

Oddball Inventions

Rube Goldberg was an engineer and cartoonist who drew goofy inventions. He illustrated chain reactions using everyday objects to perform tasks like opening an umbrella. Goldberg died in 1970, but people continue to build machines inspired by his drawings.

Most of these contraptions rely on , such as pulleys, levers, and ramps. These machines use physical principles to make easier. Pulleys, for example, can help lift something too heavy to move another way.

Rube Goldberg machine makers link simple devices into elaborate compound machines. “It’s amazing what these kids come up with,” says Kathleen Felix of Rube Goldberg Inc., which runs the contests.

Recipe for Success

What makes a winning machine? First, it should be creative, says Regan Couch. She’s on a Rube Goldberg machine team at Purdue University in Indiana. They start brainstorming months before the college-level contest.

A contraption should also work without any assistance from people, says Couch. To make sure that happens, teams need to fine-tune each step.

Simple machines help control the in each part of a contraption. A ball rolling down a ramp speeds up. A lever can turn a downward push from the ball into an upward push on another object.

One of Couch’s favorite tools is a mousetrap. This spring-loaded device stores . When it snaps, it releases the energy, setting another object in motion.

Step by Step

Making a Rube Goldberg machine takes dedication. Mia’s team worked on their umbrella-opening machine every day over spring break.

Mia worked on one step where a tennis ball needed to roll down three ramps in a row. But the ball kept bouncing off, stopping the machine. Mia spent four days adjusting the ramps to get the ball rolling just right. “You have to have a lot of patience,” she says.

Finally, it was time to run the machine for the contest. With cameras rolling, a student released a stuffed seagull that zipped down a cable to start the machine. Mia’s team watched as objects rolled and flipped one by one. As a final platform fell away, the umbrella opened. The students cheered—the machine worked!

Mia’s team won first place in their age group. But they aren’t resting easy. They’re hard at work on their machine for this year’s contest: a contraption for applying a Band-Aid.

Create a Contraption

Use simple machines to build a trap

Observe

Rube Goldberg machines are complex devices. They use a series of simple machines to complete a task. There are six simple machines. They are the lever, the wheel and axle, the inclined plane, the wedge, the screw, and the pulley.

Define the Problem

Can you build a device that uses at least three different simple machines to trap an action figure?

Materials

• cardboard square about 46 by 46 centimeters (18 by 18 inches)
• shoebox
• small toy or action figure
• paper cup
• construction materials shared by the class (Teachers: See page T2 in this issue’s Teacher’s Guide for suggestions.)
• pencil and paper

Design a Solution

KATE FRANCIS

1. Use the poster that came with this issue to study the six types of simple machines.

2. Use the construction materials to build a few different simple machines. For example, you could make a pulley out of a spool, a straw, and some string. Be creative!

3. Compare your machines with those of your classmates. Did they build theirs differently?

4. Try using your simple machines to move an object. Some ideas: Roll a marble down a ramp at an object to push it forward. Use a pulley to drop one object on top of another to push it down.

KATE FRANCIS

5. Brainstorm ways to use simple machines to trap your action figure. For instance, a pulley could lower the paper cup onto it. Or a lever could push the shoebox on top of it.

6. Design your trap. It should use at least three different simple machines. They should create a chain reaction that ends with trapping the action figure. Draw your design. Then build it. Use the cardboard square as a base. That way you can move your trap if needed.

7. Test your trap. Did it work? Make any changes you need. Then test the trap again. Keep testing and changing your trap until it works.

Conclusions

1. Which simple machines did you use in your trap?

2. How did each simple machine help the trap work?

Create a Contraption

Use simple machines to build a trap

Observe

Define the Problem

Can you build a device that uses at least three different simple machines to trap an action figure?

Materials

Design a Solution

KATE FRANCIS

1. Use the poster that came with this issue to study the six types of simple machines.

2. Use the construction materials to build a few different simple machines. For example, you could make a pulley out of a spool, a straw, and some string. Be creative!

3. Compare your machines with those of your classmates. Did they build theirs differently?

4. Try using your simple machines to move an object. Some ideas: Roll a marble down a ramp at an object to push it forward. Use a pulley to drop one object on top of another to push it down.

KATE FRANCIS

5. Brainstorm ways to use simple machines to trap your action figure. For instance, a pulley could lower the paper cup onto it. Or a lever could push the shoebox on top of it.

7. Test your trap. Did it work? Make any changes you need. Then test the trap again. Keep testing and changing your trap until it works.

Conclusions

1. Which simple machines did you use in your trap?

2. How did each simple machine help the trap work?

Continue the Learning Journey

Watch the video "Rube Goldberg Competiton" below to view a crazy Rube Goldberg machine in action. Then plan and design your own contraption to accomplish an easy task, like flipping a light switch! Use at least three simple machines out of the following six: lever, wheel and axle, inclined plane, wedge, screw, and pulley.

Build and test your own crazy device to do a simple task. Does it accomplish your simple task? If not, revise and test your machine until it works. Then make a video of your crazy machine and share it with friends!

Physical Science

Forces & Motion

Teaching Resources

videos (1)

Rube Goldberg Competition

Physical Science

Watch a video about a prize-winning Rube Goldberg machine and how it works.

Games (1)

Chain Reaction

Physical Science

Play a fun science game about simple machines.

Text-to-Speech