2021 — Gear+generator+stl

That was the first sign of real trouble for Elara, a scavenger working the high ridges of the old transmission towers. For three hundred years, the planetary generator—a colossal, buried machine the size of a city—had hummed beneath the rusted soil. It turned the planet's geothermal churn into a low-frequency pulse that powered the weather regulators. But now, the pulse was stuttering.

Various gear types can be generated in STL, including: gear+generator+stl