Compound Gear Train Simulator (2D)

This 2D simulator draws a five-gear compound train from above: a small input gear drives a chain of progressively larger and smaller gears meshing one after another, each turning the opposite way from its neighbor. Set the input speed and watch every gear's RPM and spin direction update live, computed stage by stage from real gear physics — each mesh's speed ratio is the inverse of its tooth-count ratio, and the overall input-to-output ratio is the product of all four stage ratios chained together. It is the same multi-stage principle used to step a fast motor shaft down to a slow, high-torque output, or to step a slow hand-crank up to a fast spinning tool.