ProjectsCollection

2.007 Robot Competition

As part of MIT’s 2.007 Design and Manufacturing I course, I participated in the 2023 2.007 Robot Competition. This course is a core offering in the Department of Mechanical Engineering that focuses on developing students’ design and engineering skills, with a strong emphasis on the creative design process and the application of physical laws in real-world scenarios.

At the end of the course is a robot competition where students build and test their own robots, competing to score the most points. In the 2023 competition, my robot placed second out of 90 students.

2.007 Design Notebook

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The 2.007 Robot Competition was my first experience designing and building a robot for a competition, and with it being a solo project, it proved to be a great learning opportunity. I used CAD to visualize and iterate on my robot’s design, machined and fabricated all parts using both the mill and lathe, programmed the controls using C++, and rapidly prototyped concepts.

Looking back, one of the most important lessons was to not be afraid to fail. I learned that failing fast and iterating quickly often leads to significant improvements and that sometimes scrapping ideas entirely is necessary for progress. Additionally, I learned that reliability and repeatability are just as important as innovation, as this was the key to my success in the competition.

Takeaways

CAD
Mill/Lathe
Sheet metal design
Robotic design
C++
Rapid prototyping

Process

Motivation

The 2.007 Design and Manufacturing I course is considered a capstone experience for MIT Mechanical Engineering sophomores and is the inspiration for high school robotics competitions like the FRC. The competition format challenges students to design and build robots to score points by interacting with mechanisms during a two-minute match. Each robot had to operate within specific power, weight, material, and size constraints while executing a competition strategy.

Having never participated in a robotics competition before, I saw 2.007 as an exciting challenge to take on.

Goals

The goal of the robot competition was to design and build a robot that scored as many points as possible in a two-minute match. With many elements to score points from, I chose to score points by placing balls into three specific slots located high up on a spinning DNA structure.

This created my design requirements for my robot:

Dimensions within the starting box of 12"x12"x16"
Extension from an initial height of <16" to >42" to reach the target slots
A precise mechanism to place balls in slots
A secure and stable place for balls to be stored when robot moved
Has to pull 25 lbf to trigger the multiplier

Meeting these requirements maximized my robot’s scoring potential based on my strategy.

2023 Competition Rules

Progress

Strategy and Competition Table Evaluation
First, I picked a competition strategy by analyzing the scoring sheet and evaluating feasible ways the robot could accumulate points within the 2-minute time limit. I determined that I would focus on pulling the multiplier and placing three balls into specific slots on the rotating DNA structure, as it yielded high scores. This approach was feasible within the time limit, required fewer actions than alternatives, but demanded precision. This generated my functional requirements that guided the design and build of the robot.

Lift Mechanism
One of the main design requirements was to create a mechanism capable of lifting the balls from a height of less than 16" to a height of over 42". After brainstorming several ideas, including x-lifting systems, folding arms, and telescoping designs, I decided to pursue a telescoping mechanism for stability and feasability.

Key risks for the telescoping design included stability when the robot reached full height, proper weight distribution to avoid toppling, and ensuring the mechanism was both strong and light. I created a rough prototype using foam core and string to simulate the pulley system, which helped me determine the necessary dimensions, understand the forces involved, and informed my motor and winch selection.

The final design featured four aluminum telescoping beams connected with Delrin to reduce friction. The beams had pulleys on one side and rubber bands on the other to reduce the force needed to pull each arm up. This design provided the necessary height while staying relatively stable.

Ball Deployment
The next challenge was to create a mechanism that precisely dropped the balls into the slots on the rotating DNA structure. The mechanism needed to reach 10 inches from the robot’s base, be light to avoid raising the center of mass, and fit within the robot’s starting dimensions.

I designed a ball holder with a stopper that allowed one ball to pass through while holding the remaining balls but found the real challenge in finding a way to deploy this without using an extra motor. I initially attempted a hinge and torsion spring system, but the heavy load from the springs created instability in the robot due to the forces needed to counteract the large moment arm.

After scrapping that idea, I developed a more reliable solution using a linear spring system that automatically deployed the ball holder as the robot extended past a certain height. This mechanism was more stable, fit within the constraints, and ensured precise ball placement during the match.

Integration of Robot Mechanisms (Lank)
With the lift and ball deployment mechanisms designed, the next step was integrating them into a cohesive robot system. The robot, named Lank for its height, had to fit within the 12 x 12 x 16 inch starting box and be stable enough to perform all tasks without tipping or malfunctioning.

I initially built the integrated robot on a temporary wooden chassis to test the functionality of the mechanisms. Then, I transferred the design to a double-layered water-jetted metal chassis. The chassis had reinforced sections to prevent sinking or bending under the forces exerted by the telescoping lift.

Lank was tested multiple times on the game board, and through calibration and programming, I was able to consistently deploy the robot and drop a single ball with a button push. The automatic ball drop and stopper feature allowed me to focus on other aspects of the robot control during the competition .

Multiplier Puller (Tank)
The multiplier puller, named Tank, was a separate, smaller robot designed to pull the heavy multiplier ring to double my score. Tank needed to be detachable from the main chassis with its own battery and motor system, as I wanted to maximize my time for controlling Lank to place the balls.

I built a compact winch mechanism for Tank that could anchor onto the railing on the game board and use that leverage to pull the 25 lbf multiplier ring. Tank was on the main robot’s chassis at the start of the match and dropped off at the beginning to handle the multiplier task independently, freeing up Lank for ball placement.

Competition Day
The final product was the combination of Lank & Tank. After many rounds of testing and refinement, the robot performed consistently, meeting all of my initial design requirements and scoring strategies. I believe the focus on reliability and repeatability helped me succeed in the competition where I got second place out of 90 participants.