.The Plug Bug & Corbin Dunn

GTW060613Mechanic, programmer, acrobat, builder, tinkerer.

Corbin Dunn’s 1969 Volkswagen Beetle is a fully electric vehicle. It has an electric motor powered by 48 stacked squares of Lithium-ion battery cells under the hood in place of the 50 horsepower gas engine that it was built with. He calls it, affectionately, “the Plug Bug.”

Dunn, who was born in Hawaii, raised in Corralitos, and now lives in a large, old A-frame house near the summit in the Santa Cruz Mountains, is a 35-year-old programmer for Apple in Cupertino, where he helped develop the iPhone and works on the framework for the Macintosh operating system. But his aptitude for intricate technical work is not limited to computers. Dunn is a tinkerer.

He loves to get his hands on things, figure them out, and make them work. Three years ago, he bought the VW Bug in San Jose from its original owner and spent the next nine months doing restoration, working at the mechanics and converting it to all-electric. He did all of the work in his home garage and figured out how to do the conversion by studying online, Do It Yourself (DIY) electric car forums.

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“Lots of people have done conversions all over America,” he says, “so there’s a good deal of information about it. It’s amazing what you can teach yourself online.”           

cover bug1For Dunn, the combination of learning online how things work and the DIY state of mind is a lifestyle. I first met Dunn downtown in the parking lot of Ecology Action, where electric car owners can charge their batteries for free by tapping into the energy collected by solar panels on the company building’s roof. He propped open the Bug’s hood, uncoiled a black cord tucked near the front and plugged the adaptor end into the charging station.

He explains, the car’s battery comprises 48 cells—the cell brand is called “Thunder Sky.” Each of the cells, which are made of lithium iron phosphate, contain 3.2 volts and 200 amp-hours—154 volts in total for 30.8 kilowatt hours. On top of each battery cell, Dunn has installed tiny LED boards, which are part of the car’s battery management system. As the batteries are charging while plugged in and discharging during operation, he can monitor the voltage of each cell on a small display mounted on the car’s dashboard. This way, when a cell reaches its max voltage, he can stop charging, otherwise the overcharge will damage the cell. And when he’s driving, he can see how many amps the car is pulling and when the battery is getting low.

Dunn also designed and wrote the software for an Arduino—a single-board microcontroller—that communicates with a charging station, or his home electricity source, and uses a timer so that his car charges only at night, when electricity is the cheapest. “That way I can make it charge only on off-hours,” he says. “That’s about 7 cents a kilowatt hour.”

He adds that this feature is almost exclusively implemented on production model electric cars, and that among the “Do It Yourself community,” his timer system is probably a first.

Dunn’s Plug Bug project was not a cheap endeavor.

He says he spent about $20,000 on the electronics and batteries. The battery pack alone was more than $10,000. He paid more in order to get the best possible range. Many people go the cheaper route and buy lead-acid batteries, which are much heavier than the lithiums, have a shorter life expectancy—only three to five years—and only get about a 20- to 40-mile range.

cover buguniThis vehicle has an approximate range of 80 miles while driving in the mountains, which makes up a good deal of Dunn’s drive time as he commutes up and down Highway 17 on his way to Cupertino, and gets about a 100-mile range on flat roads where he can maintain a 55 miles-per-hour speed.

But Dunn’s Plug Bug is remarkably powerful. It can put out the equivalent of 100 horsepower, twice that of its old internal combustion engine.

Dunn invites me into the car—a two seater since he pulled the rear seats out for additional battery space. Inside, the Bug still has its old-car feel: wind-up windows, an archaic seat belt system, and the original 1960s steering wheel.

“It’s no speed demon, but it’ll go up to 95 or 100 [mph],” he says. “You don’t really want to do that though, because it’s an old car and gets a little shaky on freeways.”

When he starts the car it is completely silent, and I ask him if it’s running.

“Oh, it’s on,” he replies.

Test Drive

As the car glides backward out of the charging station and onto the street, Dunn suggests we give the acceleration a test and guns it forward down Walnut Avenue, our bodies pressing back against the seats. Dunn says he didn’t choose the Bug for efficiency—in fact, the Bug has considerable drag due to its bulbous shape—but rather because he admires its classic style.

“I’ve always been into the dropped down, lowered Bug look,” he says. “I love old cars, plus Bugs are easy to work on.”

cover bugdudeWhile figuring out the logistics for converting the Bug to electric, he also reacquainted himself with his old physics text books, noting that he “brushed up on power and how much energy it takes to move a body of mass. That way I could do the math and figure out how large of a motor I would need to move the Bug at 70 miles per hour up Highway 17. I did the calculations in kilowatts and made spread sheets and simulations, and what not.”

Dunn goes on to explain that there are many kinds of upgrades DIYers do for their electric cars: performance tuning, powerful motors, larger battery packs, and the list goes on.

“People race these,” he says. “This is my first project, but eventually I want to do an old ’33 roadster style car and make it fast.”

Further proof of Dunn’s need for speed: he has owned a variety of motorcycles since he was 18 and currently has a speedy Ducati and a Harley Sportster.

After making a loop around Pacific Avenue in the Plug Bug, Dunn suggests that I take it for a spin. The car, originally a manual shift vehicle, starts in second gear rather than first, and when the clutch is released, it doesn’t stall. The car has plenty of torque, but tops out at 5,000 revolutions per minute. Another reminder of the car’s roots is its lack of power steering and the play in the wheel.

“You kind of have to put your shoulders into the turn,” Dunn advises. “I like to tell people, ‘It’s the oldest modern car around.’”

I drove the Plug Bug with Dunn in the passenger seat down to the Wharf and then back up Pacific Avenue just before dusk. The ride was smooth and quiet, which is a stark contrast to the sound a traditional 1960s VW Bug tends to make when running on a gas engine: clamorous and rollicking, like a tractor on its way to the scrap yard.

Back in the Ecology Action parking lot, a man driving a silver 2012 electric Ford Focus pulled into the space alongside the Bug. His eyes lit up when he saw the old Beetle hooked up to the power station. Dunn says people, especially electric car owners, often get excited when they check out the Plug Bug.

Sometimes people don’t even believe it.

The DMV provides Dunn with a Clean Air Vehicle decal, which authorizes him to drive in the carpool lane. Highway Patrol has pulled him over five times because they don’t believe a VW Bug could possibly qualify.            

“They’ll come up to me on the road and ask, ‘How did you get that sticker on this car?’ I tell them, “’The DMV gave it to me.”

While snapping photos of the Bug, the man with the Ford Focus leaned affectionately on the  Plug Bug. “It’s nice when people go to an extreme like this,” he says, gesturing at Dunn. “It just takes a whole lot of tinkering and figuring things out.” He glanced over at his Ford Focus and back at the Bug. “You know, I’d rather have this.”

Tinkering and figuring things out sums up Dunn pretty well. He loves a good challenge and he constantly keeps himself busy with projects.  After high school Dunn went to Arizona for aviation training, aiming to become an airline pilot. He quit just before finishing and went into programming—a shift that on its face seems like a less stimulating career.

“I realized that aviation wasn’t all that challenging,” he says. “You learn to fly the plane and that’s about it. In programming, you’re solving problems all day long. You have to constantly learn new things.”

He says that challenge is the same reason he loves to ride a unicycle—an activity he embraced with his ex-wife. “You really have to want to figure things out. And the people who are good at it are the ones who put in  time.”

Up in the mountains, Dunn’s address is marked on the road by a white circular saw blade with a stencil of a red monkey hanging on the trunk of a Redwood. He calls the property “The Monkey Playground,” because, he admits, he is kind of like a monkey.

At Home
In his living room Dunn has an “aerial silk” cloth hanging from the high ceiling as well as an aerial rope, for midair acrobatics. Next to those is the frame of a large metal cube suspended from the ceiling—a project he welded together in the garage. Dunn climbs into the cube, bracing himself at the center, and spins in circles.

Dunn uses his garage space to weld, machine, experiment and build all kinds of interesting things. He often makes custom parts for his unicycles and has even invented alternative unicycle models. One is a tandem seater (very difficult to ride, he says) and another is recumbent—designed for the rider to sit back with the feet out horizontally in front (also very difficult to ride, he repeats).

cover plugbugIt was in his garage that Dunn extracted the Bug’s gasoline engine, gave the car its glossy white and red paint job, re-welded the seats, and completed the nine-month Plug Bug conversion.

The backyard is also a tinkerer’s dream, and the area that earns the place the title of The Monkey Playground.

Dunn built his own unicycle riding course among the trees—a series of slanted pathways made from wood—where he once broke his nose and suffered a mild concussion.

He also rigged a zip line running from a pine tree down to a deck perched in a nearby redwood tree. When he was getting married to his now ex-wife eight years ago on the property, he convinced her to let him ride the zip line down to the alter. She opted to walk up the isle like a normal bride. The couple divorced three years ago.

After declaring that he assumed “zero liability,” Dunn insisted that I ride the zip line.

After proving myself on the zip line, Dunn let me in on his plan to build an entire “Ewok Village” in the trees surrounding his house.

“It will be a bunch of mini tree houses up in the redwoods,” he says. “There could be extension bridges going from tree to tree and lots of cool stuff.”

He pauses: “I have lots of ideas, just never enough time.”           

Dunn also teaches circus arts in San Jose. One of his specialties is the Cyr wheel—a big metal hoop, perfectly circular, with a diameter about his height.

In the Ecology Action parking lot, Dunn pulled out the folded sections of his own hand-crafted Cyr wheel, which was crammed into the back of the Plug Bug next to a unicycle.

He stood on the inside perimeter of the hoop and began to spin like a human dreidel.

“It’s a unicycle where I’m the hub and the spokes,” he says of the contraption.

After spinning a few revolutions in the lot and acquiring a few spectators, Dunn dropped forward and spun along the outside edge of the loop, pulling his fingers up just in time before they get crushed against the pavement. He calls this trick “the human coin drop.”

Dunn sees his Plug Bug project as a good example of what people can accomplish by themselves with access to online information and a can-do attitude.

“Many people don’t try doing things because they think they can’t do it or are afraid of failure,” he says. “I really believe everyone has the ability to learn just about anything, and it’s just a matter of trying. People realize many things are within their reach, and they become more aware of just what they can do if they spend some time learning. This applies to anything—from making an electric car, to learning how to weld, to learning a language or learning how to dance.”

Dunn says that DIY state of mind is nurtured by online communities where people sharing knowledge.

“I think the Internet community is what is allowing more and more individuals to jump on the DIY bandwagon,” he says. “They really go hand in hand, and one builds upon the other.”

In that way, Dunn says, the DIY mentality becomes a lifestyle.

Learn more at corbinstreehouse.com. Photos: Keana parker


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