Well lets see, I am not planning to build it immediately, I am just getting the stuff together that I will need to have to do it. Probably in a year from now.
Now I have thought that a 20 food dome would be good, but it may end up a bit smaller. I want to be able to project both the northern and southern skies and also I want to be able to switch the constilation pictures on and off. Which means that it will have to be a form of dumbell with some wide angle projectors at the base of the star spheres.
It would be nice to show the precession of the equinoxes which can be done in a couple of ways, and naturally it has to have sun moon and planetary projectors too. I want stars up to at least 4th magnitude. (Yes I know ....... Lots and Lots of drilling)
So all in all I would say it is a small project
I am thinking of using a 20 or 22 inch ball or pair of balls for the star spheres. I would like to use metal as it is much easier to work with, but I would rather not have to have some spun.
By that time I will have a machine shop that is more complete, so the making it won't be a problem.
So as far as time goes, well I will be working on it in my spare time, I will be building a house sometime around then so that will be not much. I plan on making the northern hemisphere first and then adding everything else as I go. So starting simple which won't take long but also having it as an element of the final projector.
Budget will be scattered over the several years that it takes to make it, so I think that it won't be too noticeable, a few hundred here and there will surely build up. I plan on making it with as many scrounged parts as possible, we will see how that plan goes.
I think that an accurate chart glued to the globe would be a real help and after each hole is drilled it can be marked off. A coloured chart would be best with different colours for each magnitude of star.
Thanks very much for your suggestions. I appreciate them.
Unfortunately those charts are in PDF format and I can't extract the graphics from them. I have e-mailed the guy who made them in 2005 and asked him if he is willing to make a mercator projection one and then pass it through a gore map making utility that is on the web. We will see what he has to say. It would be nice to have one even if it is showing less stars. It would be nice to have some good resources available on this forum, plans or diagrams etc. and some good how-to information. I will pass on what ever I come up with. It is good to share information.