Scarecrow

When is it best to use these?
They are ideal to use after you have worked on the principle and main activities, and you wish to find out how well your students can find and apply knowledge in designing and problem-solving. Each assignment is cross-referenced to the principle and main models. The students will creatively adapt their previous experiences with pneumatic concepts to solve the design task.

How to use them?
The assignment page is intended to be printed and handed out to your students. The page describing objectives, motivation, etc. are for you.

How to customize the designing and making activities to fit your students.
For the less experienced designers or where you need more control over demands on materials, hand out the assignment and give them a specific design brief. A design brief can limit the range of possible solutions, and make it easier to compare the various ideas that students come up with. For experienced designers, just handing out and presenting them with the assignment section should be enough for them to start designing.

A local organic farmer has a lot of problems with birds eating his crops. He knows from experience that when he runs into his field waving his arms wildly and jumping up and down the birds fly away. Shouting at the birds without the movement, however, has little effect. He has tried using a conventional scarecrow, which does not move. Although it frightened the birds away in the beginning, they soon became used to it and it no longer makes any difference.

Your task is to design and make a pneumatic scarecrow model that moves in a way that will scare off the birds that are trying to eat the farmer’s crops.

Motivation
Instruct the students to look at the picture of the scarecrow or search the Internet to learn about the appearance, shape and form of traditional and unconventional scarecrows.

Relating knowledge, skill and understanding to the task at hand
Instruct the students to…
• Ask yourself how you might create the scarecrow?
• Ask yourself which parts of the scarecrow will move and how you might achieve this movement?
• Ask yourself how you might decorate your scarecrow so that it looks as real as possible?

Look at:

Whilst the designing and making is in progress, encourage the students to discuss…
• If the movements of the scarecrow make sense in terms of scaring off birds.

When the activity is finished, encourage the students to evaluate…
• How the various scarecrow parts work?
• How well does the scarecrow work and whether it is reliable or not?
• Is the Scarecrow efficient? Test this with the manometer.
• How is the model decorated to look like a scarecrow?