Some extra info that doesn't specifically belong in another step:



Using 2mm LEDs as 'Stars' in corrugated cardboard substrate:

If you want to use 2mm LEDs, the round section tends to be quite short, and may not fit all the way through a substrate. A good way to mount these LEDs into cardboard is shown in the first diagram; by drilling a 2mm hole, then cutting a small slot across the back of it (only cutting through the back face of the cardboard), the LED can be pushed through into the substrate itself with only the tip of the LED poking through to the other side. Perfect! (This works really well, and is by no coincidence the method my Star Map MkII uses)



Making the stars flicker

When you watch a fiber-optic tree or UFO Lamp, the fibers tend to change colors. This is a cool effect, and something that you could either use as-is, or modify slightly to have the stars change brightness rather than color. As the second diagram shows, a problem is that the color wheel inside the base needs to be quite large, and may increase the depth of the star map significantly. A possible solution might be to construct a 'color belt' instead of a color wheel (see third diagram), this would allow you to keep the depth relatively shallow, and the only increase in depth would be the motor body.

Commenter frollard had an even better design for flattening the color/flicker mechanism - see his diagram in the comments.



To have the large stars flicker, you may be able to use 'flickering' Christmas lights, or go all-out on the electronics side, make the LEDs individually controllable, and implement a multiplexing function that can display multiple levels of brightness.



Fiber Kinks

Take care with your fibers. If they are bent too sharply they will craze, and light will spilled out in the wrong place. If done carefully, you may be able to intentionally use this property to make stars of different brightnesses.



Multi-Sourced Star Map

As commenter AlphaRomeo suggested, one way of having multiple levels of brightness could be to have multiple trees/lamps in the same area. Bright stars might use fibers from tree A, medium stars from tree B, and faint stars from tree C... and each tree could have the brightness of the light source set appropriately.



I think this would look fantastic, but it would probably be very difficult to accomplish without getting everything tangled up.



