From Vegas to Your Desk: Carl Bugeja Miniaturizes the Iconic Sphere Venue with Flexible PCBs
This baseball-sized globe contains 945 LEDs and creates gorgeous interactive animations
Carl Bugeja's latest project video illustrates what happens when a flexible PCB design expert miniaturizes a gigantic LED-based landmark. The Mini Sphere is a baseball-sized globe with 945 LEDs that replicate what the Sphere venue in Las Vegas venue can do, but Bugeja's sits on a desk.
For comparison, the Sphere in Las Vegas covers 81,300 meters². Its wraparound LED screen contains 1.23 million LED pucks, each containing 48 diodes. Bugeja's Mini Sphere contained 945 LEDs and 305 capacitors on four-layer flexible circuit boards with a six-centimeter diameter.
One approach to replicating the patterns the Sphere can display is to utilize persistence-of-vision (POV) with rotating LEDs. However, Bugeja took a different path since the actual venue does not spin. Instead, this project became a spiritual successor to Bugeja's Sphere Display, which was a ping pong ball.
It should not be surprising that the final solution uses flexible PCBs! The underlying structure is a Geodesic Sphere, which uses triangles. Using help from online calculators, Bugeja took a DXF drawing and then designed a flexible PCB design that repeated four times for five total.
Bugeja walks through the various iterations it took to build the final Mini Sphere. Like all real development efforts, each prototype version corrects mistakes and helps show better building techniques. For example, due to ambient temperature and humidity, Bugeja discovered that the flexible PCB's adhesive could lose its stickiness over time. Fortunately, a short bake-out process before applying it to the enclosure surface improved the adhesion.
Bugeja programmed several impressive demo patterns to demonstrate the Mini Sphere's capabilities. However, the best effort is the Emjoi. Unlike the building, Mini Sphere reacts to being picked up and even shaken!
The Mini Sphere's build cost is a fraction of the $2.3 billion spent on the real Sphere. Despite the inclusion of a large number of LEDs, a relatively exotic PCB material, and labor, the one-off project cost of $250 is a small price to pay for a stunning desk ornament.
Check out the Mini Sphere Build video above to learn more about its process and materials. As always, Bugeja is open to feedback on making this project more interesting or practical (cost-wise.)