To make a crane for a school project, here is a clear step-by-step guide based on a simple cardboard crane model that uses a pulley system to lift objects:

Materials Needed

• Cardboard (e.g., cereal box cardboard)
• Toothpicks
• String or wool thread
• Paper clips
• Scissors or box cutter
• Glue (hot glue gun and/or super glue)
• Pencil or old pen body (for axles/pulleys)
• Ruler and pencil for measurements

Step-by-Step Instructions

1. Prepare the Base

• Cut a rectangular piece of cardboard about 20x15 cm. This will be the base of your crane

2. Make the Crane Arm (Boom)

• Cut two identical cardboard strips about 20x4 cm each.
• Cut one end of each strip at an angle (around 50 degrees) to form the arm's tip.
• Join the two strips parallel to each other with toothpicks spaced about 3 cm apart between them.
• Glue the toothpicks to secure the arm structure

3. Attach the Arm to the Base

• Secure the angled ends of the arm to the base cardboard using glue.
• Add extra cardboard pieces for support at the joint to strengthen the arm-base connection

4. Create the Pulley System

• Make two small pulley wheels by cutting four cardboard circles (about 3 cm diameter).
• Use small plastic tubes (from an old pen body) as axles inside the cardboard circles.
• Glue the cardboard circles and tubes together to form pulleys

• Insert one pulley at the arm's tip and another at the base connection point to guide the string

5. Assemble the String Holder and Axle

• Cut two identical cardboard pieces (about 8x4 cm) to hold the string spool, attaching them behind the arm on the base with a 3 cm gap.
• Cut a circular cardboard piece (about 5 cm diameter) to serve as the spool.
• Attach a toothpick through the center of the spool to act as an axle.
• Insert the axle through the string holders so the spool can rotate freely

6. Add the String and Hook

• Tie one end of the string to the spool axle.
• Thread the string over the pulleys on the arm and base.
• Attach a paper clip or small hook at the free end of the string to serve as the crane hook

7. Make the Load Carrier

• Cut a small square piece of cardboard (about 10x10 cm).
• Use two pieces of string (about 25 cm each) crossed underneath the square and secured at the edges.
• Tie the ends of the strings together and attach them to the crane hook to hold the load

8. Test Your Crane

• Place a small object on the load carrier.
• Turn the spool axle handle to wind the string and lift the load.
• Unwind to lower the load

This simple cardboard crane project demonstrates basic crane mechanics including the use of pulleys and a winch system to lift objects. It is suitable for school science or STEM projects and can be enhanced with additional features like counterweights or a rotating base if desired

. Videos and detailed images can be found online to help visualize each step if needed