The Death Star Project...
First, let's build some reduced Star Wars favorites,
smaller ships is the only way to make a Death Star possible...
X-Wing[1]: Front-right view, Luke Skywalker and his light-saber
X-Wing[2]: Front-left view
X-Wing[3]: Rear view, R2D2 guides Luke to the victory
X-Wing[4]: Top view
Y-Wing[1]: Front-right view, Luke Skywalker and R2D2
Y-Wing[2]: Rear view
Y-Wing[3]: Bottom view
Millenium-Falcon[1]: Top view, this ship is unfinished
Millenium-Falcon[2]: Bottom view
Millenium-Falcon[3]: Rear view
Millenium-Falcon[4]: Top view, opened door and roof dish
Tie-Fighter[1,2]: Front view and Rear view
Second, let's build an equator baseplate for a reduced Death Star,
the equator baseplate is made from 4 spaceport units...
General view: The four spaceports, holding rebel ships and two tie-fighters
So, let's build this spaceport unit...
Spaceport Unit: Step 1
Spaceport Unit: Step 2
Spaceport Unit: Step 3
Spaceport Unit: Step 4
Spaceport Unit: Final Step
Third, it's up to you to build a complete Death Star...
The main baseplate seems quite robust and may be a good starting point to build a top-half death star. The suggested plan is to build additional ring baseplates from the main baseplate up to the northpole. These rings do not need to be complete. Actually complete rings whould lead to repetitive design (by symmetry) and heavy building. What I also imagine is to suspend the death star at the middle of my play room. Then, because the death star is just a half sphere, the interior can be accessed by bottom. But, waiting more inspiration, I have to delay the project...
Be (very) patient, may be some day the light will come...
Or may be you want to build your own. Then, good luck!