As diffusers, ping-pong balls are economical and they’re effective. But you know what else they are? An inconvenient size! An LED strip with 30 LEDs per meter puts individual LEDs about 33 mm apart.

[david] designed an LED ping-pong ball display using 3D printed components, which allows for the construction of arbitrarily-large LED displays thanks to a strictly modular design. The basic unit ...