This allows LED strings to point all in the same direction (more or less), and diffuses the LED light to a cylinder shape.

This is a small clip and diffuser shell that works on "bullet" style LED string - commonly seen with WS2811 and WS2801 type RGB LEDs strings.

The clip bends to open so that the 3 wires (may need tweaking for 4 wire strings) can be inserted into a slot, and then the head of the LED pushed into the clip which has a smaller diameter at the top to hold on to the LED snugly.

It's intended to print with thin walls and fairly quickly in mass quantity, but those are adjustable.

I used this with Pixelblaze and 8 output expanders to make a giant hanging 8x8x8 cube of LEDs: https://twitter.com/im889/status/1324768092442906624