@Dan_Richelson : oops! I did the spinal tap thing and misread that as 10 FEET! 10 inches is still seriously bright with a thousand pixels though…
@JP_Roy : I’ll try to get you that info ASAP; don’t have it handy right this moment.
@Mark_Kriegsman
Sorry to ‘bug’ you again on this subject,
First, no rush for any answers as I am only in the ‘early pondering’ stage of development. Just wondering if you simply forgot about it… 
I want to build a sphere (maybe even 2 as table lamps !?) similar to yours but with 400 ~ 500 RGB LEDs. My main difficulty is to find an economical way to assemble and disassemble these lamps. I intend to make this a nicely finished item on a fine hardwood base.
For now, I am basing my design on the 10" diameter sphere I found at my local IKEA. I do not have that sphere on hand now but from the description it is made of glass and I am unlikely to be able to modify it to simplify assembly/disassembly. I am curious about the sphere you used and wonder if it would be a better choice for my design.
From the IKEA assembly pictures, It seems the bottom opening is ~ 5" (Just a guess here…). If you insert a fully assembled internal LED sphere, like you did, you are then limited to a 5" diameter and I suspect that the RGB LEDs are too far from the diffusing surface and some kind of ‘focusing’ device had to be used. I guess that’s why you had to go with little pvc tubes, to help ‘focus’ the light from the LEDs. I want to decrease the distance between LED and diffusing surface such that the tubes are not required. That will help with increasing the number of LEDs that can be used.
I would probably use WS2812b devices on mini-boards, because they are thin. The minimum LED pitch would be 1 cm. I would like to test the optimal distance of the WS2812b to the diffusing material. For now, I will guess it is about 1" distance meaning that I may be able to make that inner ball (probably styro !?) as big as 8" diameter. That is if I find a way to get it through that narrow 5" opening (Hey, they make ships in bottles… this, in theory, should be simpler !)
Using sphere area calculations, 4PIr² where r = 10 cm, (8" ~~ 20 cm) I get an area of 1260 cm². I will not populate more than about 80~90 % of that so that makes 1008 cm².
Taking a more conservative 2 cm² area per pixel, I should be able to use around 500 LEDs !!
Thanks for your help Mark, JP
Hey @JP_Roy , I just finally found the orb shell that I’m using there: It’s a sixteen-inch “Orb Shell” from Save-On-Crafts.com.
http://www.save-on-crafts.com/orb16.html
About $100 (not cheap!).
@Mark_Kriegsman
Thank you very much for that link, they carry a number of different orbs and gives me different options to consider !!