"The drawing of all the different wires. I use an unused CAT5 cable for the wiring. Not the strongest kind of wire, but I needed a *lot* of wires, and not too much weight as it has to hang from the ceiling obviously. I estimate I used a total of 300 to 400 meter of wire (1000 to 1300 feet)! Here you can also see the 7 different circuits I used."
examples:
http://www.instructables.com/howto/planetarium/
commercial home planetariums go from around $30 up and have features like changeable skies and rotating in sync with the earth's orbit.