This orrery, made by marian from Lego, models the movements of the Sun, Earth and Moon with accurate rotational and orbital periods, axial tilts and lunar precession (the inclination of the moon's orbit is "exaggerated to make it noticeable"). There are two cranks to operate it and even a 12-sided stand representing the Zodiac. The plans, available as a PDF from Rebrickable, cover 264 pages with 436 detailed steps.
The orrery allows you to demonstrate these astronomic phenomena:
The astronomical origin of days and years
The origin of the seasons, solstices and changes in day length throuhgout the year
The origin of the climate zones of the earth
Sunrise and moonrise and the apparent motion of the sun and moon across the sky
The moon phases
The tidal locking of the moon
The different appearances of the moon depending on latitude
Solar and lunar eclipses
The change of the visible constellations on the night sky througout the year
Inclination, orbital nodes and precession
The difference between sidereal and synodic movement
