The author discusses how Lego is shifting the focus of the Technic series away from functional models, leading them to build their own orrery out of Lego Technic parts. The orrery is a scientific instrument that models the motion of celestial bodies, accurately representing the orbits of the Earth, Moon, and Sun. The unique design of the orrery includes features like the Earth’s axial tilt and the Moon’s inclination orbit. The author details the complex gear sequences used in the mechanism and developed a digital tool to find suitable gear ratios. The final design has 70 gears and runs smoothly after overcoming challenges. Instructions for building the orrery are available for purchase online, although the project wasn’t a commercial success. A lower part-count design with simplified features is also discussed, utilizing parts from Lego’s Rough Terrain Crane set. Ultimately, the author’s passion for Lego and celestial mechanics shines through in the creation of this imaginative project.
https://marian42.de/article/orrery/