Show students the materials.
Give them their challenge: make a device that turns when they blow on it.
(They can be tested outside in the wind, but this is less reliable and satisfying.)
They do not need to make a stand for it - have them focus on the mechanics of the spinning part.
For younger/less mechanically-minded students, explain the key design components:
A 'pivot': parts that can rotate around each other.
'Blades' that can catch the wind: larger surface areas that the wind can hit and push against.
It is useful to refer back to these if students get stuck in their designing.
Optionally show different ideas for making a pivot (see second photo):
1. a skewer in an inverted tube/pen cap (to which the blades can be attached)
2. a skewer through a straw (to which the blades can be attached)
3. a blunt pin through an enlarged hole in a straw
There are other ways to make a pivot, but these are simple ones I have seen so far.
For some student groups the design components may be best introduced sequentially.
First all students make a pivot, then share each others’ designs.
Then students choose any of the pivot styles displayed, make their own pivot, then design blades to attach to their pivot.
For older and more mechanically-minded students, they can work with the materials for a while, before naming/explaining the parts.
After a while, naming and explain the design elements of 'pivot' and 'blades'. This will help students that are still to start on a design, and conceptually frame designs already in progress.
For Kindergarten students, provide them with tube-and-skewer pivot, cardboard, scissors and tape. Demonstrate how the tube spins on the skewer. Draw and name shapes that they could cut out of cardboard ('rectangle' and 'triangle' good to include), to tape to the tube. They can add more shapes if they want. Depending on how they tape the blades onto the tube, and so how floppy the blades are, they may need to be shown how to strap a strip of curved cardboard across two blades to hold them steady.
Allow students time to freely experiment, discuss ideas together (and share good ideas with each other, as all designers and architects do).
The Play-Debrief-Replay method for teaching works well for this activity - see notes in the resource.
If students are in need of help, either ask them to visit other wind machines that are spinning in the classroom, or help them focus on some ideas (e.g. see pivot ideas above).
Once they are done experimenting, review the different ways of making the key machine elements (pivot; blades to catch the wind)
During discussion, refer to uses of machines that turn in the wind:
Wind turbines are used to generate electricity: the energy in wind turns a blade which runs a generator to make electricity. Wind turbines are in greater use with increasing sustainable energy practices. Wind turbine diagram of parts: https://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Wind_turbine_…
Wind pumps are wind machines that can be used to pump water for farming or for groundwater extraction. Photo of a wind pump: https://en.wikipedia.org/wiki/Windpump#/media/File:Wind-powered-agricul… Video showing wind pump mechanisms of gears and pump: https://www.youtube.com/watch?v=BugXmDxC0WM
Windmills were commonly used for grinding grain. They are complex machines of levers, wheels and gears. Windmills in the Netherlands: https://en.wikipedia.org/wiki/Windmill#/media/File:KinderdijkWindmills… Windmill diagram showing gears transmitting wind energy to millstones: https://tringlocalhistory.org.uk/Windmills/images/03/Schematic%202.jpg
Anemometers measure wind speed - cups that spin around a shaft. Using magnets, the number of turns is translated into wind speed.
Wind vanes have a blade that turns in the wind, but its position stabilizes to show the direction that the wind is coming from.
