Photograph courtesy of Heidi Kumao and Michael Flynn
HOMEBREW
Our 6,000-volt Wedding Cake
Our rotating, sparking, 6,000-volt
wedding cake was the highlight of our wedding ceremony, because our collaboration on this project represented the way we approach our life together.
Our design began with gear-shaped cakes, symbolizing the way our lives have meshed. We agreed that the cakes should actually rotate, so we mounted plywood gears on large lazy Susan bearings, with one of the gears driven by a 10 rpm electric motor.
We decided the traditional cake-topping figures should be recognizable caricatures of ourselves, and that a spark should jump between the hands of the bride and groom to represent passion. The spark was provided by a 12,000-volt neon-sign transformer, which we hid in the huge “Wed-O-Matic” gift box underneath. The electric current traveled from the transformer to the figures through electric motor brushes that scraped together under the rotating lazy Susan bearings. It was important to avoid arcing the current through the ball bearings themselves, so the sliding electrical contact was made on the uppermost disc of each bearing. Jumper wires ran the current from the top plate of the bearing, through our three cakes, up the figures’ legs, and out through their arms.
The completed machine was finally ready for its first test run five days before the wedding. We left the drive motor’s frame ungrounded for fear of attracting sparks to the motor, forgetting that the neutral wire inside the motor windings is itself a path directly to ground. When we energized the transformer, sparks sizzled and leaped, destroying the wiring inside our specially ordered, slow-rpm motor.
Luckily, Heidi always orders a spare motor for her art projects. We grounded the new frame so that any stray sparks could be grounded without entering the motor’s windings. We ran the transformer at half power, and we found that it still produced sparks adequate to jump between bride and groom. This cake was too dangerous to leave plugged in, so we demonstrated its full function only during the cake-cutting ceremony. We played a fun, cartoon-style tune by Raymond Scott, “Powerhouse,” and wore oversized safety goggles for dramatic effect.
You can see the video of Heidi and Michael’s 6,000-volt wedding cake performance at heidikumao.net/wed.html.
