An orrery is a mechanical model of the solar system. This is some work in progress of an orrery that depicts the orbits of the Earth and moon around the Sun. All the gears were machined from brass stock on a 3 axis CNC mill. This orrery has five gear trains that independently control: the orbit of the moon around the Earth, a pointer showing the perigee of the moon's orbit, a cam causing a tilt in the moon's orbital plane, the fixed angle of the Earth's axis (relative to a global reference frame) during orbit, and a 100 year counting dial. I'm hoping to post an Instructable on this project soon.
First tests of assembled orrery design.
Machining gears from flat brass stock on a Tormach mill. Smallest diameter endmill used = 1/32".
Exploded view of the 3D model, designed in Fusion360.