Hello everyone!
Here is my latest creation, an orrery displaying the three inner planets.
http://www.youtube.com/watch?v=0pv04_gqBOk
I rounded off the real orbit period numbers so that they would be easier to recreate using lego gears.
The real orbit period for Mercury compared to Earth´s orbit period(1 year) is 0.241 and I rounded it to 0.25.
Venus´ real orbit period is 0.615 and I used 0.6.
To figure out what gears I should use I divided 1 with 0.25 for Mercury and 0.6 for Venus(1/0.25 and 1/0.6).
This got me the numbers 4 for Mercury and 1.66.. for Venus(1 year on earth is approximately 4 Mercury-years and it is also approximately 1.66.. Venus-years)
The moon should complete 12 revolutions per orbit (12 months a year) but i just had the very small space on the ´´arm´´ that holds Earth to place gears on so the closest I could get was to have it completing 11.66.. revolutions/months per year/orbit.