Paper Windmill Test Rig

Find out which blade shape catches the most wind — with paper, a straw and a fan.

Materials

• —Card stock or cereal-box cardboard
• —Bendy straw and a wooden skewer
• —Tape, glue stick, scissors, ruler
• —A paper cup and a 30 cm length of thread
• —Small paperclips (as weights)
• —A desk fan or a breezy window
• —Notebook and pencil

Steps

1. 1. Look first10 min

   Watch a fan or a real wind turbine video. Write down what you think makes blades spin faster: size, angle, number of blades?

2. 2. Build the hub20 min

   Push the skewer through the straw so it spins freely. Tape the straw upright to a cup or box base.

3. 3. Make three blade sets25 min

   Cut three sets: two flat blades, three angled blades, four curved blades. Label each.

4. 4. Lift test25 min

   Tie the thread to the skewer with the paper cup on the end. Point the fan at each set from the same distance. Add paperclips until it can't lift. Record the max for each set.

5. 5. Look again10 min

   Which won? Was your guess right? Change one thing about the winner and test once more.

Field Notes

Write these in your notebook when you finish:

• □What I assumed
• □What the data showed
• □One change for next time

Inspired by William Kamkwamba — read their story in the Nobles library.