Grouping: Individual or pairs
Take-home: Working tabletop crane
Key ideas: Pulley, direction of force, stability, lever arm, load and counterweight.
Start with: Lift the same small load directly and then by pulling downward through a fixed pulley.
Success check: Crane lifts a standard load at least 20 cm without tipping.
Try changing: Base width; boom length; counterweight; pulley position.
Preparation: Prepare pulley/hook sets and structural kits; make one stable and one top-heavy example.
CNC preparation: Excellent CNC job: tower sides, boom, base, pivot holes.
3D-print preparation: Recommended: pulleys, hooks, axle bushings.
Lesson flow: Day 1: build
Day 2: lift tests + improve
Video:
Build a Pulley Crane
Safety and cleanup: Secure test masses; cap axle ends; safety glasses during load testing.
https://www.instructables.com/DIY-Cardboard-Crane/
https://www.youtube.com/watch?v=F_QnmzXnC-o