I wanted to make an Orrery (model of the planets orbiting around the sun) after fielding some questions from my son, about such things ……but first I thought Id make a Astrolabe here are some that are on the net either old (1300s) or reproductions.
very nice !! but my small saw and patience wasnt up to it……..yet, I will try again…..my attempt ended up as the dial on a grandfather clock I made , as a sailors astrolabe and a working planisphere
the astrolabe isn’t accurate but the planisphere works……set it to the time and date and it shows the stars in the sky at lat 35 deg north (Oslo)… so if im on my way to Oslo at night with my large clock and I get lost…………..no drama !
So , on to the Orrery……the oldest one is the Antikythera mechanism found on a shipwreck in Greece dated at around 125 bc. it was used to calculate the position of the stars etc. for navigation……here’s anouther one…. more my styleit shows the nearest three planets to the sun and the moons rotation around the earth at any time of the year, in the different signs of the zodiac so this one is for astrology actually…….
And so, on to my attempt————
The more observant will notice that the handle has gone and has been replaced with an air piston…. it all works I promise…..the next piece of nonsense is to connect it to a boiler and ill have a steam engine powered orrery…..the only one in the world…… watch this space…….or u tube.
updated orrery to show the moons orbital perturbations….its perigee and opogee……. its up and down motion, of course its not to scale or correct in any way.. and the earth should be tilted……but hey its made of wood and glue…. give me a brake !
and now the utube link .. http://www.youtube.com/watch?v=yQcTD6WS2F4&feature=channel