Lesson 7: Improving Your Machine

Any complex machine, such as your burglar alarm, is made up of many simple machines. How many simple machines can you see in and around this airplane?


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Often during testing, you first look at each piece of the machine by itself. You look at it one simple machine at a time. Then, you think about how you can adjust the simple machines to make your device better.

Before you begin testing and improving your machine, read about another inventor and problem solver.

 

A Great Scientist

Jacques Cousteau
You may know about the underwater filmmaker, Jacques Cousteau. Jacques Cousteau, with an engineer, Emile Gagnan, invented the Aqualung (scuba) in 1943. The scuba let people dive and breathe underwater. Cousteau designed the device to solve a practical problem. He didn’t want to keep coming to the surface to breathe.

© 2006 Jupiterimages Corporation		 Cousteau helped design many other things:
  • the Diving Saucer (a two-person submarine that could dive 300 m below the sea surface)
     
  • the Sea Flea (a one-person submarine)
     
  • the Conshelf (an underwater platform 100 m below the surface of the sea; six people could live and work here for three weeks at a time)
Cousteau made many films and wrote several books on the ocean. His work introduced people to the underwater world. Cousteau died in 1997 at the age of 87.
The Cousteau Society continues Jacques Cousteau’s work. The Society helps to protect and preserve the environment.

To discover more about Jacques Cousteau’s life and inventions, go to the Internet site for the Cousteau Society.

http://www.cousteau.org

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Activity 7: Making a Better Burglar Alarm

In the Lesson 6 assignment, you tested and checked your machine. You checked its ability to solve the problem of catching a cookie thief.

Now it is time to try to improve your machine.

What you need


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What to do

Discuss your design problems and possible changes with your home instructor. You want to be sure that the new design does not add any safety problems.

1. You need the answers you gave in question 5 of Assignment Booklet 2B. Copy each “Yes” and “No” answer by putting an X into the Making a Better Burglar Alarm chart.

2. The chart asks questions about problems that you may have found in your machine. Use the questions to help you list improvements that you can make.

3. Did you have any other problems with your burglar alarm? List them in the empty spaces in the chart. Suggest how you could solve these problems in the “Improvements” column.

Making a Better Burglar Alarm
Observations Yes No Improvements
Did the string break or stretch?      
Was the string attached well to the trigger and to the noise-making device?      
Did the string run well through the pulley?      
Did the pulley come loose?      
Does any part of the alarm need to be moved to a different position?      
Was the noise loud enough to hear from a distance?      
       
       

You have looked at ways to make a device better. You can think about the forces involved, the materials used, and the placement of each part in the machine. You looked carefully at possible problems in your burglar alarm. You suggested ways you could improve your design.


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Suggested Answers

Activity 7: Making a Better Burglar Alarm

1. You need the answers you gave in question 5 of Assignment Booklet 2B. Copy each “Yes” and “No” answer by putting an X into the Making a Better Burglar Alarm chart.

2. The chart asks questions about problems that you may have found in your machine. Use the questions to help you list improvements that you can make.

3. Did you have any other problems with your burglar alarm? List them in the empty spaces in the chart. Suggest how you could solve these problems in the “Improvements” column.

1.–3. Answers will vary. Sample answers are shown in the chart on the following page.

Note: It is possible that your machine worked very well and few, if any, improvements are needed. Keep this chart. You will need it for Activity 8.

Making a Better Burglar Alarm
Observations Yes No Improvements
Did the string break or stretch? X   Use stronger or more rigid string or rope.
Was the string attached well to the trigger and to the noise-making device?   X Add tape, staples, or glue; tie tighter knots.
Did the string run well through the pulley?   X Build “rims” on the pulley so the string doesn’t slip off.
Did the pulley come loose? X   Staple, tack, glue, or nail the pulley to its location.
Does any part of the alarm need to be moved to a different position? X   The pulley needs to be placed higher above the noise device.
Was the noise loud enough to hear from a distance?   X Have the objects crash against each other from a greater height.
Could the string move the noise-making device?   X Use less heavy materials for the noise device.

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