Designing for Burning Man: the Shrumen Lumen

Now, two years later, we’re pushing the limits of our skills by building the project’s next iteration: Shrumen Lumen. This time around, we’re skipping flowers in favor of 12 to 18 foot-tall kinetic mushrooms. Thanks to a totally different geometry, this project is a lot harder to build. But with hard work from an enthusiastic team of volunteers and help from a Burning Man Arts grant and our Kickstarter campaign, the Shrumen Lumen will soon be ready for the Playa. Here is how we’re making it happen.

The vision

To kick off the design process, we looked back at what made Blumen Lumen work so well. Several principles stood out.

1. The flowers had a minimal footprint on the ground but created a huge interactive space.
2. The grouping of flowers was beautiful from afar, but people could also interact with a single flower.
3. The structure was scalable. We were able to build one prototype quickly to figure everything out, then mass-produce as many as we could afford, both in terms of time and money.
4. The flowers were quick to install, and packed up neatly in a shipping container.
5. Mechanical interaction made the flowers interesting during the day, while lights added a new element at night.

We folded a lot of those takeaways into the design, sketching out a garden of five mushrooms that are big enough to provide shade during the day, and can also change shape and light up at night. Just like the flowers, we wanted people to be able to interact with individual mushrooms, but also wanted to add an interaction point that controls all the mushrooms together.

Origami at scale

The geometry of the mushrooms is based on the folding pattern of an origami magic ball. The beauty of that structure is its ability to expand and contract; the challenge is that it’s much harder to control, and, as we found out later, much harder to fold at scale.

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We jumped straight into prototyping, and planned to use the same method we had used to build the flowers: Route the patterns in corrugated plastic, fold them so that they would “memorize” the fold lines, unfold them, then weld them together. But while each flower was made of only two 10 by five foot pieces, the mushroom heads were made of 12. We’d also never worked with this origami pattern at this scale.

Unfortunately, this fold pattern was much trickier. It took a team of eight people a full hour to fold the first three-piece sheet. The plastic also cracked in several places. To make the process easier, we changed the orientation of the corrugation by 90 degrees, and asked the router shop to make shallower cuts into the plastic. The new the fold lines made the pieces much stronger, and we actually managed to fold an entire sheet of 12 pieces (though it did take 10 people).

Setting the Shrumens in motion

To make the mushroom heads contract and expand, we needed to build a solid mechanical structure, kind of like an umbrella, that would connect the folded plastic to an actuator. We experimented with a 1:12 paper scale model to figure out where to attach the actuator, and prototyped the speed of the movement. Since there will be significant stress on this structure, all the parts had to be machined. We were extremely lucky to have Jim Feuhrer (and his five decades of experience in building) to help us create them.

Building a safe structure

Last time around, when the wind came up on the Playa, we could just close the blooms to prevent the flowers from tipping over. It’s much harder to make the Shrumens more aerodynamic, so they had to be carefully engineered to withstand 60-plus mile per hour winds. To hold the origami structure in place, we mounted 1 1/4 inch aluminum tubes around two aluminum hubs. One of the hubs is mounted to the top of the actuator and can move up and down, while the other one is mounted to the stem.

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The entire head assembly slides into a 6-inch, thin-walled steel tube that is mounted onto a 3.5-inch-thick wall pipe. Luckily, with some minor modifications and reinforcements, we were able to recycle the base we used for the flowers to anchor the system.

Designing the digital interaction

Not only are we installing 1560 LED lights in each mushroom, we are also designing ways for visitors to interact with the mushrooms. By standing on certain pads, burners can change the color and movement of the Shrumens. Each pad can also measure weight, so, for example, if two people hop on a certain pad, more of the structure will turn red.

To make this work, we are using a network of Raspberry Pis in each stem. Powered by 12 volt batteries, the minicomputers control both light and movement. Each of the 1560 LEDs in the stem and cap are independently addressable, and the chip in each LED only uses one pin for data input and output, so they must be controlled with precise timing. The team chose to use a Pixel Pusher microcontroller because of its power (it can control 4000 LEDs) and built-in libraries. Processing, running on the Raspberry Pi, pushes color combinations and scenes. The Raspberry Pi also monitors the load cells, which are placed in those lighted platforms at the base of the mushroom. When visitors step on, these load cells can trigger the mushrooms to change shape or color.

The team

Of all the projects I’ve worked on, this one required the most manpower (by far). Thanks to 40-some weekend warriors—a mix of highly specialized experts and enthusiasts who picked up new skills like soldering, metal cutting, or drilling—Shrumen Lumen is about to happen. It has turned into a highly sophisticated installation, and I can’t wait to see it in the desert.

Special thanks to everyone who helped bring Shrumen Lumen to life: Ali Hasanbeigi, Anthony Wainman, Angie Kim, Annette Diefenthaler, Blake Durtsche, Bomani McClendon, Britta Durtsche, Dali Yu, Dave Sumberg, David Brody, David Good, Diem Ho, Gabrielle Fulco, George Joseph, Gilles Roux, Gina Romero, Hannah Williams, Henry Hsiung, Janko Potezica, Jazz Tigan, Jesse Silver (production lead), Jessica Pastor, Jim Feuhrer, Jimmy Chion, Joerg Student, Justin Chang, Kalan Kircher (digital lead), Lauren Fundora, Leo Marzolf, Nathalie Collins (digital co-lead), Nicholas Leverone, Nivi Ramesh, Olivier Notteghem, Peter Bronk, Rachel Frey, Remy Pieron, Sam Starr, Steve Moore, Victoria Cao

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