How To Build A Trick Shot Machine For A Harlem Globetrotter

How To Build A
Trick Shot Machine For A
Harlem Globetrotter

They were supposed to be building chairs out of cardboard.

Some of the students in Kevin Shankwiler's class were even excited about the prospect. They were newly enrolled Master of Industrial Design students with years of learning ahead of them.

"We have a really exciting project," Shankwiler told the class. "The Harlem Globetrotters want us to build a trick shot machine, and we're going to do it before the semester ends."


The undergraduate students in Tim Hsu's Introduction to Audio Technology I class heard a similar announcement.

The trick shot machine assignment would probably be one of the most complex projects his students would tackle as undergraduates. And it would happen in a foundation-level class for the newly established Bachelor of Science in Music Technology program.

What were these instructors thinking? Is this what the School of Industrial Design and the School of Music mean by "rigorous academics"? Would the students pass their class and survive the semester?

The machine would be operated by a Harlem Globetrotter, and have several complications, much like a Rube Goldberg machine. The goal of the machine would be to throw a basketball into basketball hoop in spectacular fashion. The project would be sponsored by the Harlem Globetrotters, and the finished product would be a video of the working machine, which would be played at four upcoming Atlanta games.

"Atlanta is our home," said Harlem Globetrotters president Howard Smith. "It was great to work with our Georgia Tech neighbors on something this fun and innovative. It was a huge effort, but it shows what's possible with great teamwork."

Shankwiler and Hsu knew the project was ambitious. But they also knew this was the perfect opportunity and the perfect lesson for both their classes.

Students standing around tables, adjusting a model of a Rube Goldberg machine.

School of Industrial Design graduate students experiment with a model of an early design for the trick shot machine.

The Method to
Trick Shot Madness

This project was an opportunity for the industrial design students to learn about the design process, Shankwiler said. Building a machine that would result in a trick basketball shot would allow his students to develop a theme, work on systems design, and execute an electromechanical design that delivered an experience that was tied into the original theme.

It would also give his students a meaningful introduction to Georgia Tech's unique approach to industrial design.

"This was an opportunity to really understand iterative design, to fail fast and fail forward. To not give up on ideas, but to get through to the end," he said. "We pride ourselves on not giving up." His challenge as a teacher was to get his students past the design assumptions they made so that they were building early in the process.

"Another aspect of this project that made it relevant to our program was that it wasn’t just about building a mechanical apparatus," he said. "It was about integrating electronics and sensor-based technology so that the experience of the machine was bigger than just the mechanics or just the technology."

The music technology students would also get to experience the perfect blend of their new discipline, Hsu said.

Part of the music score built by the Georgia Tech music technology students for the trick shot machine.

The music technology students synchronized the sounds triggered by sensors the score of their composition.

“Our degree program is called ‘Music Technology,’ and this project really captured the meaning of both sides of that: music and technology. We try to integrate those ideas equally—our students take traditional music courses as well as technology courses—and this project allowed us to do that deliberately," Hsu said.

While the industrial design students were charged with building the enormous mechanisms of the trick shot machine, the music technology students were challenged to turn a kinematic motion into sound, and then turn that sound into music.

"So much of the field of music technology, including new instruments and interactive musicianship, deals with sensors and how the outside world affects music composition. Some of the machine’s complications were all electronic, some of them were acoustically based, so we were able to use real and electronic sounds and turn that into a composition,” Hsu said.

The trick shot machine gave the students exposure to Arduino, Ableton Live, max/MSP, force sensors, and flex sensors, he said, as well as how to use those sensors in situations where gravity affects the outcome.

Buckets helping students adjust the trick shot machine.

Rollercoaster Ride for Students

"We've never had a collaboration of this scale before," Hsu said. "Not only between schools in the College of Design, but between undergraduates and graduates." Normally School of Music students are separated from the rest of the student body because their building is located on West Campus, he said.

"To go to a different building and be inspired by the surroundings and the collaboration was such an opportunity," he said.

According to Carter Culwell, a third-year electrical engineering and music technology dual major, the opportunity felt like a gigantic mountain at first.

"As soon as the project was announced, I felt a lot of pressure. It's a huge project, especially for a class of undergraduates. But after we organized small groups with the industrial design students, we could tell that we had an achievable goal. We divided the one big task into smaller tasks that were feasible."

Fellow music technology major Kate Bosen found working with graduate students was an inspirational bonus.

"The idea of the project was exciting, but I was kind of skeptical," she said. "Are we really going to be able to do this?"

"It felt a little more real after seeing the industrial design students' visions of the machine crafted so well. That's when I knew that we could go and apply the music aspect of the machine. It was good to watch their leadership, even though they have a completely different set of skills than we do," Bosen said.

"As a person who's considering going to graduate school, it was eye-opening."

Mark McJunkin and Do Hee Park stand next to a basketball chute that she welded.

Mark McJunkin, left, and Do Hee Park, right, stand next to a basketball chute that she welded.

The undergraduates didn't need to be so worried, said Andy Harper, one of the industrial design students who was on a team with Bosen. "From our perspective as graduate students, we were blown away by the ideas that the music school students were coming up with. In a way, it was humbling."

"You walk into this project, really new to the program, and you hope you represent yourself well. The reality was many of us felt like we had so much to learn before we could actually accomplish something like this."

But the students were supported by their professors as well as the School of Industrial Design staff at the Digital Fabrication Lab, where the trick shot machine was assembled. Hsu said his students especially appreciated the guidance they got.

"We had undergraduates who have never picked up a drill before, fastening parts of the machine," Hsu said.

"Mark McJunkin is a master fabricator," Shankwiler said, "he taught all the students to weld. We had a neuroscientist [Master of Industrial Design student Do Hee Park] welding by the end of it. That's pretty awesome."

The students learned from each other as well, said Master of Industrial Design student Sahana Srivatsan.

"The teaching was back and forth," she said. "The team for the first complication worked really well together. We had the music technology students come in on work days to see how we were progressing, and what the scale of that part of the machine was like so that they could see where to put their sensors and understand the timing."

For someone who is used to communicating visually through the objects they design, it was fun to watch other students from the same College make music work in harmony with movement, she said.

Georgia Tech
Basketball Practice Epiphany

One of the most valuable lessons of all came from the Georgia Tech men's basketball team, Srivatsan said. As part of her classmates' research into trick shots, the Harlem Globetrotters, and the mechanics of basketball, the students got to observe a Georgia Tech men's basketball team practice at McCamish Pavillion.

"What I noticed most were the different sounds that were made as the players practiced," she said. "For me, that was really exciting because I started connecting the dots between sound and this machine."

"We also got to see some of their training machines. They had something called a 'Passback' where you throw the ball and the machine rebounds it to you. They also had something called 'Dr. Dish,' that throws a ball back to you after you throw the ball into a hoop. Those specialty products definitely influenced our design."

Harper said studying the rudimentary movements of passing warmups was also an influence on the complication designs. It was difficult to faithfully reproduce some of the players' ball handling or any of the more acrobatic moves, but the fun and entertainment of the sport inspired most of the machine's actions, he said. Especially the trebuchet at the end of the machine.

"It turned out to be powerful enough that it put a crack in the backboard of the hoop that we were using. Those guys did a really good job with that!" he said.

Storyboard sketch for the conveyor belt complication. Credit: School of Industrial Design

Storyboard sketch for the dribbling machine complication. Credit: School of Industrial Design

Storyboard sketch for the ball kick complication. Credit: School of Industrial Design

Storyboard sketch for the passing machine and drum descender complications. Credit: School of Industrial Design

Storyboard sketch for the wave complication. Credit: School of Industrial Design

Storyboard sketch for the mannequin pass complication. Credit: School of Industrial Design

Storyboard sketch for the ball spinner complication. Credit: School of Industrial Design

Storyboard sketch for the hamster wheel complication. Credit: School of Industrial Design

Storyboard sketch for the face ramp complication. Credit: School of Industrial Design

Storyboard sketch for the rotating baskets complication. Credit: School of Industrial Design

Storyboard sketch for the levitating ball complication. Credit: School of Industrial Design

Storyboard sketch for the catapult complication. Credit: School of Industrial Design

Teamwork Conquers Failure

Basketballs aren't small, and a machine that can throw a basketball into a hoop needs to be large. Shankwiler and Hsu knew the scale of this project would be larger than any they had ever assigned. Even the parametric modeling classes Shankwiler teaches only produce items a fraction of the scale of this trick shot machine.

Choosing the Digital Fabrication Lab as the location for the machine -- a 13,000 square-foot high-bay shop owned by the College of Design -- was key, Shankwiler said. Even so, he and Hsu both chose to have their students start by designing tiny models. Instead of a basketball, the industrial design students worked with ping pong balls.

"To get us acquainted with the idea of a simple machine, Dr. Hsu had us create little mini Rube Goldberg machines in one of the rooms in the Couch building. We had all kinds of weird stuff going on. My team had balloons flying on ramps all over the room," Kate Bosen said. "It was a good primer for the trick shot machine."

The trick shot machine had 12 complications:

  • Intro and Conveyor Belt
  • Dribbling Machine
  • Ball Kick
  • Passing Machine and Drum Descender
  • The Wave
  • Mannequin Pass
  • Ball Spinner
  • Hamster Wheel
  • Face Ramp
  • Rotating Baskets
  • Levitation Machine
  • Catapult

In total, the project took 12 weeks to complete. The completion is what made this project more challenging than most, Hsu said.

"Most of the time you have a project at the end of the semester and it's kind of half-baked," he said. "Maybe it takes 45 minutes to set up, and it only works 15 percent of the time. The fact that we had to deliver a machine that would work so that it could be filmed forced the students to get to a point of completion that we as professors never see."

"We got to see the iteration, the trial and error. The Hamster Wheel, I don't know how many iterations we went through to get the bucket to work and the wheel to not spin out of control. Maybe a dozen? It was nice to see something go beyond the first prototype," Hsu said.

The design iteration of the trick shot machine was heavily influenced by learning how to work on a team, Carter Culwell said.

Parts for the trick shot machine wait to be assembled in the Digital Fabrication Lab. Credit: Andy Harper

The trick shot machine spanned two stories of the Digital Fabrication Lab, as well as half the length of the building. Credit: School of Music

Students work on a complication of the trick shot machine that moves a basketball along by using authentic Harlem Globetrotter sneakers to kick the ball. Credit: School of Music

This pinball board moves a mini basketball from one complication to the next. Credit: Himani Deshpande

A mini basketball bounces on three drums as it progresses to the wave complication of the trick shot machine. Credit: School of Music

Each complication of the trick shot machine included sensors that trigger sounds and parts of the soundtrack. Credit: School of Music

Students work on the ball pass complication of the trick shot machine. Credit: School of Music

The ball spin complication is designed to spin a basketball so that a Harlem Globetrotter can knock it into the next complication of the machine with a giant boxing glove. Credit: School of Music

The hamster wheel complication is powered by a Harlem Globetrotter, whose effort raises a pulley carrying a basketball to the next part of the trick shot machine. Credit: School of Industrial Design

Students fine tune the angle of metal rails so that a basketball lands in the next complication of the machine at the right time. Credit: School of Industrial Design

A leaf blower powers the hovering ball complication. Credit: School of Music

The last complication of the trick shot machine is a catapult that shoots a basketball through a standard sized portable basketball hoop. Credit: School of Music

"We do a lot of failing at Tech, and it makes learning somewhat more like the real world. There are hard deadlines, things you've got to do within a certain amount of time, you've got to cooperate with other people, and if some people don't do their parts then other people fall short," he said.

"This project was giant, with lots of moving pieces. When some people had minor failures, those created ripple effects and hurt other people in different groups. We had to quickly learn that it wasn't just about us doing our part. It was about us doing our part and fixing the failures of other people because we were all working on the same project."

Bosen agreed. "I think we've all experienced how many Georgia Tech group projects can turn out, so we all braced for the worst. But it all ended up going really smoothly."

'Buckets' Blakes
Makes It Work

When the trick shot machine was fully set up the morning of the video shoot, the students were in good spirits. After a long weekend of heavy testing, the complications of the machine were working predictably.

"It's funny," Harper said. "It was one of those things where the trebuchet was working perfectly in practice sessions, and on shooting day, you get Murphy's Law. Something was a bit off."

And then, in walked "Buckets" Blakes, the Harlem Globetrotter who would operate the trick shot machine. As the students tried -- and tried, and tried, again -- to coax the complication back into working order, Blakes brought their fighting spirit back.

"He offered good advice on being able to pinpoint where the ball fell short. He suggested trying to move the trebuchet forward a few inches or work with the angle that the ball was leaving the trebuchet, and where that fell with the basket. He became like one of the students at that point because he was willing to keep going with the trial and error."

"It was amazing to see what these students designed and built," Blakes said. "The way the machine sent the basketballs through the different parts was mesmerizing. It made my job easy!"

The trick shot machine team poses with 'Buckets' after a day of filming.Credit: School of Music

When the cameras were on, Blakes was clearly a pro. "To see this person up close is pretty cool," Harper said. "When the cameras start rolling, he's got a ball spinning on his finger and he's operating three different things in a span of 20 seconds. He came into this room with the giant contraption we'd made, and he was able to operate the different facets in minutes. It showed me the importance of spatial intelligence for someone like a Harlem Globetrotter."

Sahana Srivatsan thought it was beyond cool. She fully admitted to fan-girling.

"Before Buckets came in, when we knew a Globetrotter was coming to the Digital Fabrication Lab, I was super excited. I didn't know which one we were going to meet. I saw the Harlem Globetrotters on The Amazing Race when I was a kid, and that's how I came to know about them," she said.

"During every meeting with Kevin, I'd ask, 'So, is a Globetrotter going to be in our video? Are we going to get to meet one?' And at first, we thought maybe they would only be there behind the scenes, or come in and shoot the machine without us."

"He brought a very fun energy. He could do all these tricks and have fun with the basketball. It made me realize that this was important to another group of people. We had been working in isolation for so long, and it felt really good to see that our work had value to another group of people," she said.

But she was also nervous. Since she was on the team that built the first complication of the trick shot machine, she feared that if the Conveyor Belt didn't work, the basketball wouldn't go anywhere, let alone into the basket at the end of it all.

"Is this whole thing going to work? Is the first part going to work? Is it going to get stuck? We had no idea, and there's this famous basketball player here," Srivatsan said. "There was a lot of anxiety."

"But since I know him somewhat personally, now, Buckets is my favorite Harlem Globetrotter," she said. "I follow the Globetrotters on Instagram, and every time he's on it I watch."