Cheers for Gears in Face-Off of Robots

It’s the fight of all fights at Caltech: Robot vs. Robot. Death (or at least maiming) to the losers. The winner takes home a 20-pound trophy of a brass gear and claims championship bragging rights to the campus’ largest spectator contest.

“It’s the closest thing at Caltech to a football game,” said physics student Hesper Rego, who with the crowd cheered on Colleen Moody, one of 23 contestants who competed Thursday in the 19th annual ME 72 Engineering and Design Contest.

The contest is aimed at challenging the analytical wits of senior-level mechanical engineering students. In September, participants were handed a bag of parts that included wires, dowels, an aluminum blind strip and a motor. They were graded over 10 weeks on their ability to design a radio-controlled machine that can drag an 11-pound cage across a platform while fending off competitors.

“It’s sumo wrestling, Matchbox and bumper-car derby,” said mechanical engineer professor Joel Burdick to the crowd of students, who whooped and whistled for the contest to get going.

Unlike popular cable TV shows such as “Battle Bots,” where the goal is to pulverize the competition, students are not allowed to inflict “intentional violence” on opposing machines, said instructor Curtis Collins.

And their grade is not affected by the outcome of the competition. Factors like dynamic force analysis count the most: you know, F=MA.

But the pressure to win made for brow-sweating competition, and professor Erik Antonsson tried to relieve the tension.”Don’t take winning so seriously,” he said minutes before the competition. “I want you to have fun. The hard work is over. Remember, if you lose, it’s not a negative element.”

At the wave of a yellow flag, 12 teams faced off in 48-second rounds of metal-clashing, torque-producing action. Some machines tried to push the cage, others used wires to winch it into the corner. They employed claws, clasps and handmade wheels. As the crowd howled, one machine careened off the platform with a loud crash. Another twirled in frantic circles before falling off the platform, landing upside-down.

“Ooh, that was decisive, that was decisive,” Antonsson announced after one round in which the machine built by Moody and partner Jesse Reynolds used a powerful winch to quickly pull the cage into the winner’s corner.

“Don’t mess with Colleen. She’s a lean, mean, fighting machine,” read a banner that her volleyball teammates dangled from the balcony. They knew all too well how hard she had worked.

“She used to come to every practice smelling like machine oil,” said Vi Tran, 20, a chemistry major.

Each team employed two machines in the effort to move the cage. Backstage, students performed last-minute repairs, filing key parts, recharging batteries, tightening fasteners.

“Anyone see my antenna?” one student asked.

“Shave down this bit,” another advised his partner, handing him a file.

“Where are the gears?” someone shouted from behind a tool tray.

The contest finally came down to Moody and Reynolds vs. Dylan Owens and Ben Solecki.

Moody-Reynolds employed a winching powerhouse -- one machine with a complex clasping arm, the other a winching device with several gears -- to tug the cage.

Owens-Solecki’s simple design and strategy called for quickly hurtling one part of their machine over the platform and then using a winch device to tug the cage.

“It’s really simple,” Owens said. “Once our machine jumps over the edge, it’s very difficult for anyone else to pull us back on the table.”

With a shout of “On your mark, get set, go!” the finalists grabbed their joysticks and the machines jumped into action. The Moody-Reynolds device moved out first, grabbed hold of the bar and began pulling the cage into a winning position just as Owens-Solecki’s robot threw itself over the edge.

The championship tug-of-war began. The crowd roared. It was a standoff. Then a loud snap rang through the hall. The Moody-Reynolds machine had burst a gear against the pull of the Owens-Solecki entry, which then dragged the cage to victory.

Cameras snapped as the spectators rose to their feet in cheers. Owens and Solecki raised the gear trophy above their heads in a victory celebration.

In the background, Reynolds cradled his broken robot like a baby.

The lesson?

“Stronger gears,” he said.