project2nd Grade2 meetingsMeeting 20

Pulley Crane

Pulley Crane https://www.instructables.com/DIY-Cardboard-Crane/ Days: 2 Mode: Individual or pairs Take-home: Working tabletop crane

Teaching & key ideas

Key concepts: Pulley, direction of force, stability, lever arm, load and counterweight. Hook: Lift the same small load directly and then by pulling downward through a fixed pulley. Test / evidence: Crane lifts a standard load at least 20 cm without tipping. Variables to change: Base width; boom length; counterweight; pulley position.

Lesson flow

Lesson plan: Day 1: build Day 2: lift tests + improve Video: Build a Pulley Crane https://www.youtube.com/watch?v=F_QnmzXnC-o Safety / cleanup: Secure test masses; cap axle ends; safety glasses during load testing.