This is a simple mount and light-pipe for SMD5050 LEDs, such as the WS2812/WS2812B LEDs. These work best with these tiny, single-LED circuit boards that let you solder strings of LEDs together in whatever fashion you need.

The mount has a shallow inset at the bottom that will help center the LED while it's glued to the mount. The light-pipe allows the LED glow to protrude from whatever project you have going. The STL provided has a 4mm length/2.5mm diameter light pipe. Any dimension can be made by adjusting the Fusion 360 file provided. I'll even take requests to provide alternate dimensions for you.

I created these to help build the EPCOT Spaceship Earth model, and I wanted to use the LEDs I had instead of buying the suggested string LEDs from Adafruit. (I still bought one string nevertheless :) )

The LEDs come as a 10x10 grid of 100 LEDs, on a pre-cut, snap-apart PCB. Available from Aliexpress. It's one of the cheapest ways to get WS2812B LEDs.

Update: Added a model with a 6mm light-pipe. The Spaceship has a thicker portion around the equator which requires a longer light-pipe.