Spare Parts

by Joshua Davis

  When he got home, his dad noticed his swollen eye and demanded to know who hit him. Lorenzo didn’t want to say.

  “Tell me and I’ll kick his ass,” his father said.

  It was the most his father had offered to do for him in a long time. Lorenzo felt a swirl of emotion. He didn’t want to get into fights, but at least his dad expressed concern when he did. It seemed possible that if he fought more, his dad would pay more attention to him. His dad didn’t seem to care about Lorenzo’s interest in robotics. Lorenzo wondered if he was trying to be something other than what he was. Maybe he was never meant to be anything more than an impoverished immigrant who brawled his way through life.

  * * *

  News of the fight spread around school the next day, and Lorenzo was called into Principal Steve Ybarra’s office. Lorenzo had been warned not to fight again, so Ybarra had the option of expelling him.

  Lorenzo didn’t know what to say or how to act. He just felt lost. “I’m sorry” was all he could say.

  Ybarra knew that if he kicked Lorenzo out of school, he’d probably gravitate toward the gangs. If Ybarra let him stay, Lorenzo would be able to continue working on the robotics team. The support of teachers—notably Fredi—might turn the kid around. Ybarra decided to take a chance and assigned Lorenzo to a second round of anger-management courses.

  * * *

  Fredi tracked Lorenzo down between classes later that day. “Come with me,” Fredi said angrily. Lorenzo dutifully followed him back to the robotics closet.

  “You’ve got to stop this,” Fredi told him when they got there.

  “What was I supposed to do? He was insulting my mother.”

  “You know, I got beat up in high school too,” Fredi said, remembering the early eighties, when he was targeted for being Iranian. It wasn’t a pleasant memory.

  “For real?” Lorenzo couldn’t imagine an authority figure like Fredi being attacked.

  “They want you to get angry. So if you give that to them, they win.”

  To Fredi, this was a battle for the future of an unusual but talented kid. He appreciated Lorenzo’s offbeat ideas and felt that the long-haired goofball had genuine talent. But Lorenzo was caught in the tractor-beam pull of poverty and low expectations. They were powerful forces to contend with. It wasn’t hard to imagine Lorenzo’s dropping out. He wouldn’t have many opportunities after that. Getting involved with WBP, his cousins’ gang, was one obvious option.

  Fredi had once been an oddball kid too. He’d wanted to build hovercrafts and didn’t get along with his parents. When Fredi was in college, he took a physics class over the summer at a local community college. At the time, his younger brother, Ali, was a straight-A student at the University of California, San Diego, and Ali taunted Fredi for attending what he viewed as a lesser school. Fredi warned him repeatedly to stop. When the mockery continued, Fredi punched his brother in the face, giving him a bloody nose.

  So Fredi could understand how Lorenzo was feeling. He also knew that anger rarely led to positive outcomes. The brothers hadn’t talked for a year after the altercation. That wasn’t what Fredi wanted, nor did he want Lorenzo to make the same mistakes.

  He decided to offer Lorenzo a novel solution: “Next time somebody wants to fight you, pretend you’re having a seizure.” Fredi simulated having a seizure, contorting himself and shaking violently. “Like that.”

  Lorenzo broke into a sly smile. The image of his teacher writhing on the floor to get out of a beating made Lorenzo giggle. He usually felt like the weirdest person in the room, but now Fredi was challenging him for the title.

  “You gotta do something, right?” Fredi asked.

  The humor helped take a weight off Lorenzo. He realized he was never going to be the ass-kicking brawler his father might want him to be. He couldn’t be anything other than what he was: a sweet kid with an unorthodox perspective. It was a perspective that lined up surprisingly well with Fredi’s.

  “I’m serious,” Fredi said. “Just flop around on the ground. They’ll leave you alone.”

  “Okay. I’ll do that,” Lorenzo said.

  Then he erupted into real laughter. It felt good.

  THE ROV’S THIRD task was going to be the hardest. According to the backstory, the U-boat sank while it was carrying thirteen mysterious barrels. Now, competition organizers explained, those barrels were leaking. It posed an “environmental danger” that needed to be quickly assessed. The robots would have to locate the barrel, insert a probe into a half-inch pipe, and extract a five-hundred-milliliter sample, all while hovering underwater. Oscar and Cristian were pretty sure the task would be impossible to complete, so they assigned it to Lorenzo. If he failed, they figured it wouldn’t set them back much, since it probably wasn’t doable in the first place. It would allow the rest of the team to focus on the more easily accomplished goals.

  The other teams in the Explorer class brought a wealth of engineering prowess to the sampling problem. MIT considered using vacuum containers and a screw-activated syringe before settling on a series of submersible bladders joined by a T-valve. Lake Superior State University used an innovative dual-pump system, while Long Beach City College employed a three-way solenoid valve. Lorenzo, left to his own ingenuity, decided to use a balloon.

  The humble balloon had a lot to recommend it. Unlike a rigid container, it carried no air when deflated so it wouldn’t add buoyancy. Some of the other teams were trying to use rigid containers that had the air vacuumed out. Lorenzo didn’t even get to that level of complexity. A balloon was flexible, could expand and contract easily, and cost almost nothing. There was no reason to consider something more complex.

  The next problem was how to suction the fluid into the balloon. Fredi suggested using a sump pump. They were often installed in underground basements. If the house flooded, the submerged pump could discharge the water, so he knew they worked well underwater. Fredi was worried that they might cost a lot, but on an exploratory outing to Home Depot with Lorenzo, they found a small twelve-volt pump for thirty-five dollars. Lorenzo also picked up some narrow copper tubing for two dollars.

  Back in the robotics closet, Lorenzo started experimenting. He glued PVC fittings to each end of the sump pump. One fitting narrowed the intake section to the size of the copper pipe. He inserted the pipe, glued it in place, and bent it so that it jutted out from the front of the bot like the proboscis of a butterfly.

  He pulled a balloon over the other end of the pump. When he plugged it in, the pump sucked up five hundred milliliters of water in twenty seconds. It worked perfectly except that the weight of the water made the balloon fall over. It wouldn’t be a problem underwater—the balloon wouldn’t fall over below the surface—but when the ROV was pulled out to retrieve the sample, the balloon would flop to the side, come off the pump, and spill the sample everywhere.

  Lorenzo tried affixing the balloon in a variety of ways, but each time the balloon fell over like a drunkard who’d lost his balance. When it did, the balloon popped off and water gushed everywhere. Lorenzo had to keep sopping up the mess. It was getting a little embarrassing, and Lorenzo was already deeply vulnerable to any mockery. Fredi worried that if the team laughed at Lorenzo’s mistakes, he might give up.

  “You’re doing good,” Fredi reassured him. “You’re getting close.”

  Lorenzo nodded. He wasn’t sure he was getting close to anything but a damp pair of shoes, but Fredi’s words made him feel a little better.

  “Maybe if I built something to catch it, that could help,” Lorenzo said.

  “Try it,” Fredi said.

  Lorenzo fished an empty Coca-Cola liter bottle out of the garbage and hacksawed it in half. He flipped the top half upside down and placed it over the pump so that it served as a sort of catcher’s mitt for the balloon. Now the balloon filled inside the container, but the liter bottle was too restricting. As the balloon expanded, it bulged out of the top of the bottle and pulled the balloon off the pump. Water sprayed everywhere.

/>   “Try something bigger than a Coke bottle,” Fredi said while Lorenzo glowered. “You’re onto something good.”

  The next day, Lorenzo showed up with an empty gallon-size plastic milk container. Fredi watched Lorenzo hack it in half, affix it to the pump, and turn the system on for twenty seconds. The balloon filled with water and gently leaned over into the molded interior of the milk jug. Lorenzo turned the pump off. The balloon lolled inside the jug, its neck securely fastened around the pump.

  Fredi was impressed. It was a practical, cheap, and ingenious solution. At the outset, he hadn’t been sure Lorenzo could pull it off. Now that Lorenzo had, Fredi felt a wave of emotion. It seemed possible that the kid might make it through after all.

  “You did it,” Fredi said, clapping Lorenzo on the shoulder.

  Lorenzo responded with a big smile. “I did it.”

  “¿QUÉ ES ESO?” Lorenzo’s mother asked him. She was holding a letter printed in English and wanted to know what it said. Lorenzo scanned it in their living room while his mother waited. It was a foreclosure notice. His mom had recently been laid off from her job cleaning rooms at a Days Inn, and Lorenzo’s dad was burning through twelve-packs of Milwaukee’s Best on a regular basis.

  “La carta dice que van a perder la casa, tienen que evacuar la casa en treinta días,” Lorenzo said. The letter says you’re going to lose the house, you have to evacuate the house in thirty days.

  When Lorenzo was nine years old, the family had scrapped together a meager down payment to buy the house. The mortgage was about six hundred dollars a month. Lorenzo’s mother insisted that she’d been paying it, but she didn’t have any receipts to prove it. Lorenzo didn’t know whom to believe. It felt as if just when things were starting to get better, something always came along to put him back in his place.

  Lorenzo shuffled through the other mail and found a letter from a Realtor who advertised his ability to stave off eviction. Lorenzo phoned him and the guy sounded helpful. He said he would talk to the bank and try to negotiate a deal. Lorenzo allowed himself to feel a moment of hope and prayed that the Realtor wasn’t a fraud.

  OSCAR AND LUIS took on the problem of what propellers to use. Part of the challenge was to figure out how many were needed and how to arrange them. They didn’t need to be enormously powerful. In fact, the more power the motors consumed, the quicker it would run down the onboard battery. At first, they reasoned that they would need to be able to go forward, backward, up, and down.

  “Three motors should be enough,” Oscar said. “Two horizontal to drive and one vertical to go up and down.”

  “What if we need to tilt to pick something up?” Luis rumbled.

  “You’re right.”

  The more they talked, the more complex they realized it was. The robot needed to be able to tip forward if they wanted the mechanical arm to pick up the towfish or the captain’s bell. Inside the submarine, the robot would need to move sideways, and that would require another motor. Maneuverability was critical, they concluded, and decided that they’d need five motors total.

  Fredi suggested they consider trolling motors, which were used for fishing boats that had to move quietly. He wasn’t much of a fisherman—he didn’t have time—but he’d seen the motors and knew they were efficient and small enough to fit inside the PVC framework. Typically, they powered aluminum boats and weren’t known for their brawn. But when coupled with a relatively lightweight ROV, they would provide a lot of zip.

  Oscar googled trolling motors and found a company called Mercury Marine. Using the phone on Fredi’s desk in the marine science classroom, Oscar dialed the 800 number and eventually got through to Kevin Luebke, one of the company’s endorsement managers. Normally, Luebke doled out motors to winners of the Bassmaster Classic, guys who liked to talk about shallow-running crankbaits and rocky riprap. Oscar had to explain that they weren’t fishermen. They were high school students competing in an underwater-robot contest.

  Luebke was charmed and quickly agreed to sell them five discounted motors. Normally, the MotorGuide motors sold for about $100. Luebke marked them down to $75 each. At a total of $375, it was still a big part of the project’s budget, but they needed reliable propulsion.

  When the motors arrived in the mail, Oscar and Luis gingerly pulled them out of the box. It was like getting a Christmas present and made the project feel even more real. They were shiny and black and had two menacing blades.

  The next question was how to arrange them. At Fredi’s suggestion, Oscar and Luis filled a marine science sink with water and plopped in a small piece of wood. They took turns moving it around the sink with their fingers and discovered that if they pushed with their fingers at a forty-five-degree angle, they were able to turn the wood much faster than if they simply pushed it directly from behind. Without realizing it, they were discovering the principles of torque. The result of their small-scale sink experiment: a machine that would be able to rotate around a central point with little drift.

  Given their limited budget, they decided they wouldn’t be able to build a waterproof housing for the robot’s control. Instead, they found a discontinued plastic briefcase at a local electronics store. It claimed to be waterproof up to fifty feet. Plus, it was on sale for $120, a bargain. Since the pool in Santa Barbara wouldn’t be deeper than fifteen feet, they figured it would be okay. They bought the case, drilled a hole in the side for the wires, plugged it, and submerged the whole thing in one of the marine science room’s big sinks. It worked fine, at least in a sink.

  * * *

  Cristian had drawn a detailed plan of the ROV, including the lengths of every segment of PVC pipe that would be needed. Since the pipe came in lengths of ten feet, it would need to be cut into pieces. They had bought a pipe cutter, but Cristian found that he couldn’t operate it. The pipe was too thick and Cristian wasn’t strong enough.

  “Con ganas,” Lorenzo teased him. “Squeeze that thing.”

  “You try it,” Cristian shot back, and handed him the cutter.

  “Déjame enseñarte,” Lorenzo said. “I’ll show you how it’s done.”

  Lorenzo clamped down on the thing. He could barely budge it. He tried sitting on it (“That’s not gonna count,” said Cristian), banging it against a wall (“Don’t mess up the wall!” Fredi shouted), and finally succeeded in breaking through the pipe by straining with every ounce of his strength.

  “See, I told you it was hard,” Cristian said, feeling vindicated.

  “Let me try that.” Oscar took the cutter from Lorenzo while Luis watched from across the room with a bemused grin. Oscar, squeezing as hard as he could, cut one piece after working on it for five minutes. He could do it—just barely—but his hands ached afterward, and they had to fashion approximately eighty pieces. Everybody looked over at Luis.

  “You want to give this a try?” Oscar asked.

  Luis lumbered over and took the cutter from Oscar. He fed a piece of pipe into the device and clamped down, cutting the pipe in one smooth movement. Everybody looked at him with awe.

  “It’s like butter,” he said.

  It took Luis two days to cut all the pieces. As he sliced through pipe after pipe, Oscar, Lorenzo, and Cristian started joining the sections together without glue to make sure they all fit. Luis did his best to measure the pieces before he cut them, but it was hard to be exact with a hand-powered slicer. Once he was done, they placed the last piece into position and stood back to take a look at their creation. It was a slightly lopsided white plastic frame.

  “That looks good,” Allan enthused.

  “Very cool,” Fredi agreed.

  In reality, it looked like crap, but there was potential.

  A MONTH AFTER the students had begun the ROV project, Dean Kamen released his annual robotics challenge. The small group working on the ROV was just a part of the larger, twenty-odd-member Carl Hayden robotics team. For this broader team, Kamen’s event was the main focus. For Oscar, Luis, Lorenzo, and Cristian, it was an opportunity to hon
e their construction skills on dry land, experience a real competition, and focus on their teamwork. They decided to join the other kids on Kamen’s challenge.

  It promised to be a lot of fun. Kamen had cooked up something akin to robot basketball. He invited students to build a machine that could range across half a basketball court and collect a variety of balls. For a portion of the game, the machines would run autonomously. The rest of the time, the kids would drive the bots from behind a ten-foot-tall Plexiglas wall. The goal was to place the balls in a tall hamper—a combination of basketball and robot warfare, as machines were pitted against one another in a dash for balls. At the end of the game, teams could earn bonus points if their robot could suspend itself off the ground on a pull-up bar.

  Kamen’s organization shipped participating teams a box of supplies to jump-start the robot building. The most important part was a robot controller, a compact-but-versatile black square that contained all the processors, connections, and radio controls needed. It packed a programmable processor able to handle ten million instructions per second and could communicate via a tether or radio. It weighed just over half a pound and was about the size of a hand.

  One of the first things they had to learn was how to solder. To build a robot, students need to be able to connect wires, so Fredi and Allan showed them all the soldering tricks they’d need to know: how to “tin the tip,” how to apply the solder to the wires, and why not to apply solder to the iron itself. After a few practice sessions, the kids were far from being experts, but they were able to forge basic connections.

  Still, there was a big difference between soldering a connection and building an entire robot. The idea of assembling a robot that could play basketball was even more forbidding.

  “What if we just don’t play that game?” Lorenzo suggested.

  As usual, Lorenzo’s ideas seemed silly at first. The other team members pointed out that the whole point of the competition was to try to play the game, even if it was hard.