Modular Design Enables Huge Ping-Pong Ball LED Displays

Detail of an LED display made using ping-pong balls

Ping-pong balls have many uses: apart from playing table tennis, they have been used for countless art projects, science experiments, and even to raise ships from the bottom of the ocean. As it turns out, they also come in handy as diffusers for LED pixels, allowing the construction of large-size displays without requiring large individual LEDs.

[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 is a small piece that holds a single LED module and has a cup-like structure for attaching a standard table tennis ball. Twenty-five of these basic units combine together into a panel that also contains wiring ducts. Finally, any number of these panels can be combined into a display, thanks to clips that give the structure rigidity in the out-of-plane direction.

A 3D-printed frame for making an LED display
A single panel holds 25 LEDs and comes with cable ducts. On the right is a clip for connecting multiple frames together.

Of course, simply mounting LED modules is not enough to create a display: the LEDs also need to be connected to power and data lines. [david] didn’t relish the thought of having to cut and strip 1,800 pieces of wire, and therefore devised a clever way of automating this process: he put a bunch of wires onto a piece of card stock and used a laser cutter to burn off the insulation at regular intervals. Then it was simply a matter of soldering these wires onto the LEDs and snipping off pieces along the data bus.

The finished panel is driven by a combination of a Teensy 3.2 to generate the data signals and a Raspberry Pi to process the images. You can see the rather impressive result in the video embedded below; if this inspires you to build your own, you’ll be happy to hear that the STL files and all code are available on [david]’s project page.

Massive LED displays are always fun to watch, and although this is not the first one to use ping-pong balls as diffusers, its modularity and open-source design makes this one perhaps the easiest to replicate. Assuming you have a good supplier of ping-pong balls, of course.

22 thoughts on “Modular Design Enables Huge Ping-Pong Ball LED Displays

    1. They are still nitrocellulose. The material is basically flash-paper slowed down by some percentage of camphor. They still burn very fast but not for long. Probably not legal for manufacturing use in lighting so be careful. The problem, if there is one, is you can’t predict how the circuits will fail. Setting fire to one of the module frames full off balls will be a nice test.

      1. @Dude said: “Still, they should be dipped half in black paint with a hole in the bottom to stop light leaks and improve contrast.”

        Yes, and the paint can act as an adhesive to hold the ball in the frame after it dries.

  1. Those colors are so washed out, with the work lights off I’d be more impressed. Video doesn’t register like the eye to color and brightness the same way.

    The earliest use of ping-pong balls must on be one of those Gen1 computers for the main display 0 thru 9 in a few rows. Decimal output not binary, wow. Digits were painted on the balls and probably a #47 lamp inside so the front is lit the best instead of like here.

    Alternative: the globes on LED bulbs, however only a few available fat chance finding a supplier. They have great light diffusing effect and are more rugged at least this side of the pond. Clive’s teardowns have them being soft and squeezable over there.

  2. I think you could design the wiring channels to isolate the wires, then just run bare wire to each LED. Alternatively, you could cut up plastic or even paper soda straws to isolate the wires, and again, just run bare wire to the LEDs and slip an appropriate length straw over it as needed.

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