Step-by-Step Instructions
1. Construct the base platform from cardboard to hold the bridge and pulley system securely.
2. Build the medieval bridge platform using popsicle sticks glued together; ensure it’s sturdy but light.
3. Assemble the two towers on each side of the bridge with cardboard or skewers to support the pulley system.
4. Create pulleys by cutting tubes or bottle caps to form wheels; attach to the top of the towers allowing them to spin freely.
5. Attach one DC motor to one tower; connect its axle to the pulley using rubber bands or string loops.
6. Tie fishing line/string to the bridge platform and run it over the pulleys so the motor’s rotation lifts and lowers the bridge.
7. Build a small cart using popsicle sticks and attach bottle cap wheels on wooden skewer axles.
8. Connect the second DC motor to one wheel of the cart with a rubber band to drive it.
9. Mount the cart on a flat track made from cardboard strips parallel to the bridge.
10. Wire both motors to the battery pack, include switches for control if desired.
11. Test the pulley motor by switching it on to raise and lower the bridge smoothly.
12. Test the cart motor to ensure it moves at a consistent speed along the track.
13. Secure all components with hot glue and reinforce any weak points.
14. Decorate your bridge and cart with markers or paint to enhance the medieval theme.
15. Demonstrate the working model by lifting the bridge and moving the cart electrically.