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Simple Machines (Smart Pulley, Lever & Gear Crane)

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Construct a laser-cut wooden crane incorporating a Lever arm, Fixed & Movable Pulley system, and Gear winch. A force strain gauge sensor measures how much less effort force is required to lift heavy weights.

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Props & Materials Required

  • •Laser-cut wooden crane construction kit
  • •Plastic pulley wheels & grooved string
  • •Weights (metal washers or rocks)
  • •HX711 strain gauge force sensor / spring scale
  • •ESP32 / Arduino controller
  • •0.96-inch OLED display

Step-by-Step Instructions

1

Lift Weight Directly

Lift a 200g weight straight up by hand. Force gauge reads '200 grams force required'.

2

Add Single Fixed Pulley

Thread string over 1 fixed pulley. Pull down to lift up. Force stays 200g, but direction of force changes!

3

Add Movable Pulley (Block & Tackle)

Thread string through a 2-pulley system. Pull string — Force gauge now reads ONLY '100 grams force required'! Work is twice as easy!

4

Test Gear Winch

Turn the small gear winch handle to lift the heavy weight easily with gear reduction mechanical advantage.

Why It Works & Notes

Simple machines (levers, pulleys, gears) make work easier by trading distance for force. Measuring the actual effort force required with 1 pulley vs. 2 pulleys gives concrete proof of mechanical advantage.