Hello fellow space-lovers! Firstly, a little background. An orrery is a mechanical model of the solar systems built to show the relative positions and motions of the planets. A grand orrery incorporates all of the planets known at the time of its making (traditional orreries stop at Saturn). The funny name comes from the Charles Boyle, the 4th Earl of Orrery, who I suppose probably liked this sort of thing.
I chose a ten planet model, incorporating Pluto and Eris, with a modified scale (see step 1). Distances, for reasons that you know doubt understand, are not to scale. My model is not mechanical, although the planets can be rotated individually.
For more information and plans to build a true mechanical orrery, check out Clayton Boyer's beautiful designs here
Edit: Thank you to everyone who voted for me in the Celestron Space Contest! As you might be able to guess, this is still a work in progress. I will post the final pictures after it is completely finished. Thanks!