Over IAP, I was sitting in a lab meeting and probably focusing a little less than I should have been. Instead I was thinking about MakeMIT. What were we gonna make? How would we do it? It wasn't a lightbulb moment, no sudden eureka, but the idea of a domino setting robot slowly formed. And the more I thought about it, the more I liked the idea. It would be novel, interesting, and require overcoming design challenges. When I messaged out to my team, another attribute got added to that list, profitable. One of my teammates had nearly been hired in highschool to construct a domino-setting robot for a person attempting to break the world-record of a longest domino chain. He never ended up constructing that robot and this would be a perfect chance. From then on, I was set on this project (though a lucky charms separator, to sort the marshmallows from the rest was a worthy challenger).
What it does
Our robot drives in a line and deposits dominos vertically, so that if one is knocked over, the whole chain will fall. It is also reloadable on the fly, meaning that one could walk along side the robot with a bunch of dominos, drop them in a chute, and have them placed vertically. Though this is not necessary, the robot itself can store more than 20 dominos.
How we built it
The design was our first priority. Once that was sorted out (which we will elaborate on later), the construction was fairly straightforward. We laser-cut acrylic, cut out foam, and assembled the bot. Superglue was our friend (though an enemy of our hands), and it all came together.
Challenges we ran into
The first challenge was simply coming up with a mechanism that would fit our specification. We wanted to be able to reload as it goes (which means dominos need to start in a stack of some sort), and we needed the dominos to end up standing vertically very consistently. Sub problems of this required changing the dominos orientation, a calm release mechanism, and a way to load from the queue. We believe that our solution is very elegant. We have a magazine, open at the top for reloading, connected to a disk with slots. As the disk turns, dominos slide into the slot from the magazine, thus separating the dominos from each other. From there, they slide down a simple ramp into a vertical position, a smooth change in orientation. And then the magic happens. The domino rests in a chute with no bottom, constrained so it must be vertical, but resting on the ground. Then a door opens and the domino is standing on its own. And its done. This design took lots of thought and we managed to simplify our solution, leaving us with a very elegant machine.
There were also challenges in the build. We had timing issues (many team members had other obligations to do). Near the end of the build, we superglued one piece slightly wrong and it caused the dominos to jam. This required furious sanding and to solve our problem. Luckily, that all worked out.
Accomplishments that we're proud of
We are very proud of our simple, elegant design. It is also flexible, though it only goes straight now, it would support turning and tracing designs. We hope to explore those options when we have the time. Additionally, we are proud of how well it turned out, considering our actual build period ended up being quite short.
What we learned
What's next for Dumbo: the Domino Bot
We have some more temporary fixes and parts that need to be replaced.
The next step for Dumbo is mostly in software. Our platform could do so much more than we have set it to do now. It could trace out paths, spirals, shapes, designs. This is purely a matter of implementation.