Jess Ong
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"operation" robot

A custom-designed RC robot for competition

2.007: design and Manufacturing I (spring 2013)
This was a semester-long individual project for 2.007, an introductory design class in which students fabricate their own robots for a competition similar to First Robotics or Botball. The theme for the year I took the class was the board game Operation. Each student was equipped a box of raw materials (aluminum, steel, ABS, delrin, etc.), a planetary gear motor, a couple of serovos, and other various components. We were also given access to a fully equipped machine shop and rapid prototyping machines. 
competition results
​In the two-day final competition, I ended up placing in the top 10 of nearly 100 students. Since this was one of my first exposures to design and manufacturing, I was very satisfied with the result. 2.007 was one of my favorite classes at MIT, and through it I gained many new skills including machining, CAD, and design intuition. ​
Picture
Main features of my robot: 
  • Custom gear-driven grippers
  • ​4-bar linkage crane allowed the robot claws to reach below "ground" and lift to about twice the height of the robot
  • Front-wheel drive provided good traction and control
  • All major parts were either off-the-shelf products or waterjetted, which made design iteration quick and easy
(Hover over images to see captions, click to enlarge.)
From the beginning I chose to focus on one aspect of the game: picking up the wrench and bones and placing them on a shelf. My first idea sketch was surprisingly similar to the concept that I ended up pursuing
A Solidwork sketch on top of a cross-section of the board. I used this interactive sketch to plan out the part dimensions to produce the desired 4-bar linkage lifting motion
Quick estimation of the torque the motor will need to provide
A simple foam core sketch model of the grippers, which were powered by the four-bar levers. This would eliminate the need for an additional servo. In this configuration, the claws are open when the lever is lowered, and close as it is lifted
This quick sketch model allowed me to experiment with grippers that would be actuated by a servo (by thumb in this photo). This is roughly the mechanism that I ended up using
Brainstorming different possible mechanisms to actuate the grippers
The Pugh chart I used to decide which type of gripper mechanism to use
Estimation of the energy required to lift the wrench. (There was an enforced energy budget for the competition)
Engineering drawing of the gripper design
The first set of claws that I fabricated. It was waterjetted from 1/4" ABS. The gear teeth fit together perfectly, with little catching or backlash. It took several iterations of different gripper sizes to find the optimal shape for lifting the wrench
The grippers were held in place by e-clips and washers. This made them easy to assemble and remove, which allowed me to experiment with different shapes and sizes to find the best design
Calculations of required component dimensions based on game board geometry
The rapid-prototyped parts. Almost all the parts were either off-the-shelf components like nuts and bots, or waterjetted. This made assembly and iteration quick, easy, and consistent
Side profile of CAD model
The final product, before being flipped to front wheel drive and fitted with counterweights and a controller and batteries
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  • HOME
  • PERSONAL PROJECTS
    • MACHINIST'S CUBE
    • MACHINED RESIN CANDLEHOLDER
    • LASER CUT PROJECTS
  • RESEARCH
    • MOBILE-ENABLED DIABETIC FOOT ANALYZER
    • BLOOD PRESSURE IMAGER
    • ROBOT FLOWER GARDEN
    • HYPOSURFACE
  • PROJECTS
    • DESKTOP LATHE
    • ANIMATION WHEEL PUZZLE
    • SOCCER JUGGLING ANALYSIS
    • DELTA LINEAR 3D PRINTER
    • GALAXY YOYO
    • "OPERATION" ROBOT
    • FIREFLY FOOTBALL
  • SPORTS
    • SOCCER FREESTYLE JUGGLING
    • ULTIMATE FRISBEE
  • CONTACT