I've always wanted an orrery. I think they look really cool. This isn't a real one - it's a desktop clock that looks like an orrery but tells the time of day. It includes three planets: a mercury-like planet, an earth-like planet and a jupiter-like planet.
Step 1: How It Was Made
Start with a dome clock and a cube clock. Both can be found in charity shops and car-boot sales. Glass domes are nicer than plastic - one should cost under £5.
Cube clocks are harder to find but should cost very little. The cube-clock motor has concentric brass tubes to support the weight of the plastic triangles.
An ordinary clock motor isn't strong enough to support the "planets".
Step 2: The Planets
The planets are made from wooden beads. I painted them with acrylic and poster paint to look vaguely like mercury, earth, jupiter and the sun.
The supports for the planets are made from steel wire. I used MiG-welding wire: it's covered in copper and looks quite nice. Bend the wire around a drill that's just a little smaller than the tube it's going to fit. That way, it will grip onto the tube.
One end of the wire is bent to hold the planet. Carefully measure what the orbit of each planet should be.
The other end of the wire will support either the sun or a time-ring.
The planets are temporarily held in place with Blu Tack.
Check that they don't collide.
The sun and inner-planet rotate as the second hand. The middle planet is the minute-hand and the outer planet is the hour-hand.
Step 3: The Time-rings
Strips of brass are are bent and soldered to form the time-rings. The wires are soldered onto the rings.
Paper scales are glued onto the time-rings. I dyed the paper with tea to "age" it.
Step 4: The Box
An octagonal wooden box forms the base. A fancy cast disk from a light-fitting forms a plinth. Both cost less than a pound at a car-boot sale. The clock motor fits inside the box lid and the box is screwed onto the base.
A pointer made from brass wire shows the current time - it is 4:51.
The planets and sun are painted and the whole thing is varnished.
A webpage describing this project is here. It has links to some of my other projects.