Old Sparky

I wanted to build something new for Roboexotica 2019. While the festival is dedicated to cocktail robotics, occasional food bots make an appearance to line visitors' stomachs for the ensuing cocktail mayhem. One fixture, the Amalettomat, has been serving apricot jam pancakes since 2011. Since sugar was already covered, I wanted to offer something savory, and what better tribute to Viennese fast-food culture than serving hot sausages?

I can't recall where I first encountered the idea (likely in some amateur video on the internet), but I knew that sausages could be cooked rapidly by running electricity straight through them. To test the concept, I cut the socket off an extension cord, soldered forks to the exposed wire ends, impaled a sausage, and plugged it into a wall outlet. Defying all reasonable survival instincts, the experiment worked: it heated a pair of Frankfurters to serving temperature in roughly 15 seconds.

Safety Warning: An AC mains cable with stripped bare ends is colloquially known as a suicide cable. It carries lethal voltage, poses severe fire and shock hazards, and should never be built by anyone. The "best" outcome of building one is that only the operator dies and nobody else, hence the drastic name of such a device.

The test proved that direct electrical heating could prepare sausages on demand, but running mains voltage through meat produced a gruesome side effect: after a few seconds of current, the contact points around the electrodes began to char, emit smoke, and throw bright sparks. It was macabre, hilarious, and surprisingly captivating, which sparked the idea to turn the byproduct into the main attraction.

History already offers a precedent for crowds gathering to watch electrocutions: the electric chair. The new concept was born: an interactive electric chair diorama where visitors condemned their own snack to the chair by throwing a heavy switch. The name came naturally: according to Wikipedia, Old Sparky was the morbid nickname given to electric chairs in several US prisons, perfectly capturing the dark humor of the project.

To build it, I modeled a miniature chair tailored for a pair of Frankfurters and 3D-printed it using wood-filled PLA. The enclosure was fashioned from a birdcage, not to keep birds in, but to keep curious hands safely away from live mains voltage. Inside, I installed an elevated wooden floor finished with 3D-printed faux tiles. For the trigger, I adapted a functional knife switch with custom 3D-printed housings for a cleaner look. Custom electrode caps with embedded forks held the sausage securely and connected to high-voltage wiring. Equipped with a master kill switch that cut all electricity to the chair, the first version of Old Sparky was ready.

At Roboexotica 2019, Old Sparky not only won the Annual Cocktail Robot Award (ACRA) for Bar Food, but also took home The Lime. The Lime is a humorous anti-prize awarded annually to the most broken, unfinished, or nasty robot. Old Sparky was gloriously nasty. Despite the questionable aesthetics, it functioned flawlessly and reliably served hot sausages all weekend.

Old Sparky went on tour. Following its debut, it was showcased in Linz at Roboexotica 2021 and Hedonistika 2022, both hosted as part of the Ars Electronica Festival. Later in 2022, the Roboexotica collective was invited to Austin, Texas, to exhibit at Fantastic Fest.

For Fantastic Fest, Old Sparky received a major upgrade. I replaced the original plastic base with a custom wooden enclosure featuring a hinged access hatch for the electronics and refined the scenic details. Audience reactions at previous shows revealed an interesting quirk: conditioned by horror movies and haunted attractions, visitors expected high drama and were slightly underwhelmed when the sausages didn't thrash or scream. Furthermore, without immediate visual feedback upon throwing the switch, users frequently assumed the machine had failed.

To solve this, I added cage lamps that flickered dramatically to simulate an immense power draw when the circuit closed. To complete the illusion, I integrated a motorized cam mechanism into the base that vigorously shook the chair's legs during execution, delivering the visceral theatrical spectacle audiences were craving. As a final touch for the US exhibition, I added small Stars and Stripes flags and placed a sausage-sized figurine, dubbed American Sausage Jesus, into the diorama to guide the condemned sausages safely to the afterlife.