Mini-pat: a model cellphone tower
Read the story above the picture at the top of the page again, then look at the pictures of six different cellphone towers in Chapter 10. Which of those towers will make the people in your village happy?
The cellphone company sends one of their employees to the village. He talks to the people in the village to find out what the designer should keep in mind when she makes plans for the tower. So he asks you:
"What are the three most important things I have to keep in mind when I design the cellphone tower for your village?"
You can start to answer by saying: "The tower must be . . ."
You can also start parts of your answer by saying: "The tower must not . . ."
Write down your answer below. You can mention more than three things if you want.
By writing your answers to the question, you have started to write a design brief and specifications for a cellphone tower.
Look at the picture of the village on the previous page. Where do you think the cellphone tower should be placed? Also decide what type of tower it should be, and make a rough drawing of the tower on the right place in the picture.
Write the design brief.
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What is the problem?[1]
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Who will be happy about the new tower?[1]
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How will it help them?[1]
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Now write the design brief. Use the answers of the questions you have just answered. Start your paragraph with:
I must design and make... [2]
Identify the specifications.
How should the tower be designed so that it will not look ugly?[1]
What should be at the top of the tower?[1]
Write down another specification, in your own words. [1]
Write down another specification, in your own words. [1]
Write down one more specification, in your own words. [1]
Identify the constraints.
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At least how tall should your model be? [1]
How much weight should your model be able to carry? [1]
You can only use materials that you can find around where you live. What are these materials? [3]
Camouflage means to cover or colour something to make it look similar to, and fit in with, the things around it.
How will you camouflage your tower?
Towers are designed so that they are stable, strong and rigid.
- Something is stable if it does not fall over or collapse easily. The opposite of stable is unstable.
- Something is strong if it does not break easily. The opposite of strong is weak.
- Something is rigid if it does not bend easily. The opposite of rigid is flexible.
How will you make sure that your model cellphone tower is stable?
How will you make sure that your model cellphone tower is strong?
How will you make sure that your model cellphone tower is rigid?
Will the materials bend too easily?
Will the tower fall over easily?
Will the tower be strong enough to support the platform at the top?
Will you have all the materials you need to build your model?
Home-made glue
1 cup flour
⅓ cup of sugar
1 ½ cups of water
1 big spoon vinegar
Mix the flour with sugar in a pot.
Add half of the water. Stir.
Add the rest of the water and stir.
Add the vinegar.
Heat the mixture until it gets thick and shiny.
Leave the mixture to cool.
Work carefully with hot
things, a stove or open flames.
Use a thick cloth or pot
holder to prevent burning yourself or others.
If you get burnt, hold
the burnt area in cold water
for 20 minutes.
Do not rub anything on the
burn.
Use tools safely
Use tools for the purpose
they are made for. Scissors are made for cutting
- not for anything else.
It is also important to use
tools correctly. If you have not used a tool before, ask
someone who knows how to work with it for advice. Keep tools
in good working order and pack them away after you have used
them.
You have already made a design for a cellphone tower. Look at it again. Make a list of everything you will need to build the model.
The tools and materials that are needed to build something are called resources.
Make a working drawing of your model on the next page. Your drawing should show what the model will look like from one side. Use a ruler and show dimensions. The drawing should be half as big as the model will be. Label your drawing to show the different parts. Show what the parts and the joints are made of.
Make a list of all the materials you plan to use to build your model. (2)
Make a list of the tools you will use to build the model. Even a nail to make holes with can be called a tool. (2)
Think of your safety when using tools. Some tools can be dangerous if they are used incorrectly. Write down one safety rule for one of the tools you will be using. (2)
Think about the order of work. This is a list of all the steps you follow when you make the model. Below is the first step. Add a few more steps. (4)
Step 1. Roll straws from scrap paper.
Step 2.
Step 3.
Criteria for working drawings
Tick
The drawing has a heading.
The heading includes the view that the drawing is drawn in, which is the front view.
The outline of the drawing is darker than the dimension lines.
The dimensions have only been written down once.
The dimensions (measurements) are written in millimetres. You don't have to write mm, because designers always use millimetres on working drawings.
All measurements are placed in the centre of the dimension line.
Arrowheads are neatly drawn on either end of your dimension lines.
The drawing is neat.
Criteria are ideas you use to judge something.
Change each of the criteria into a question you will ask, and write the question in the evaluation sheet below. Work as a team.
- Your model should be no less that 300 mm (30 cm) tall.
- It should have a flat platform on the top. In a real tower, such a platform is used by engineers when they need to work on the top part of the tower. You will use two A5 textbooks to test if your tower is strong enough to hold the radio transmitters and receivers.
- The model should fit in with the surroundings. It should be camouflaged in some way.
- The model should be made from strong materials to keep it stable.
- It should also be rigid and hold its shape.
- Your model should show reinforcement through triangulation.
Criteria
Good
3
Medium
2
Poor
1
Work on your own. Use the evaluation sheet on the previous page to evaluate the tower you and your teammates have built.
Join your teammates and compare your evaluations. Discuss it and try to agree on a final evaluation.
Write your questions into the following two evaluation sheets. You will use these sheets to evaluate towers built by other teams.
Criteria Model of team A
Good
3
Medium
2
Poor
1
Criteria Model of team B
Good
3
Medium
2
Poor
1
Plan your presentation.
- All the team members have to talk aboutthe work they did when they built the tower.
- One learner has to show and explain thedesign sketch. Tell the group how you plannedto make the tower fit in with the surroundings.
- One learner should talk about the problemsthe group experienced.
- One learner should talk about how thegroup tested the tower.
- Decide who will start and who will talk next.
Use the space below to write notes about what you will do.
Hints for presenting
Stand up straight and look at the class when you speak.
Do not read your presentation.
Speak clearly, so that everyone can hear you.
Know when it is your turn to speak.
Keep to the time limit.