The Challenge:

Create an animation highlighting how the gearbox in one of NASA JPL’s EELS (Exobiology Extant Life Surveyor) 1.0 modules works to counter-rotate the ice screws using only one input motor and one input gear. The counter rotation of these screws, one with clockwise threads and one with counter-clockwise threads, is the primary mechanism for propelling EELS forward along its central axis. This key feature of the 1.0 design was important to communicate to key stakeholders in the following gate review.

The Solution:

Christiahn completed the animation in Blender by starting with standard gearing formulas for the purple carrier, yellow sun, and ring gears but, due to the different diameters and tooth-count of the red and blue planetary gears, he had to multiply each rotation by some percentage until all of the gears fell into sync with one another. Without access to the original formulas from the engineering team, and with a lot of trial and error, he was able to reverse engineer the rotation rate calculations for this unusual and unique gearing system.