Grouping: Pairs or individual
Take-home: Cup anemometer
Key ideas: Wind speed proxy, rotation, counting, calibration idea.
Start with: Show rotation count changing when fan speed changes.
Success check: Count rotations in 15 seconds at two fan settings; repeat.
Try changing: Cup size/orientation; arm length; fan speed/distance.
Preparation: Pre-punch cups for some classes; set fan speeds/locations.
CNC preparation: CNC not needed.
3D-print preparation: Print a safe central hub if replacing pushpins.
Lesson flow: Day 1: build
Day 2: calibrate/test
Video:
How to Build an Anemometer
Safety and cleanup: Teacher manages pushpins or use printed hubs; eye protection during fan testing optional.
https://www.sciencebuddies.org/teacher-resources/lesson-plans/make-anemometer-measure-wind-speed
https://www.youtube.com/watch?v=KummzMtaI6Y