A wooden waterwheel is driven by a flowing stream of particles filling its buckets, turning a gear train linked to a mill building. The stream is a 2,400-point buffer geometry where each particle follows a simple physics loop: it drifts downstream, then falls under a simulated gravity term as it passes through the wheel's capture zone before recycling upstream. The wheel's rotation directly drives three procedurally extruded involute-style gears through a chained angular-velocity ratio, mimicking a real mechanical gear train.