Let’s JAM Team 35: Jason Chen, Justin Ho, Andrew Wilkinson Presenting: The Jammer

Components of Robot Andrew Wilkinson

Objective Get balls onto own field White balls = 1 pt Yellow balls = 2 pts meh... Oooh! Shiny! Andrew Wilkinson

Robot in Three Pieces Friction Drive Arms Elevator Andrew Wilkinson

Step One: Getting In Position Increase vertical height starting position arms raise up robot at maximum height Controlled by one geared motor Justin Ho

Step Two: Driving to Balls Use friction drive to move forward Robot ready to get balls Justin Ho

Step Three: Dragging Off Balls Score points! Give me that! Mine mine mine I got one, but it’s not enough! Grasp balls using arms Drive backwards to pull ball back Ball falls onto soccer field! Justin Ho

In Real Life! Justin Ho

The Animation! Justin Ho

Initial Design: Scissor Lift Problems ●Difficult to extend scissor lift with only 1 motor ●Complex design; aiming for simplistic design ●prone to jamming After our risk reduction test, we decided to use an elevator mechanism to raise our robot instead. Jason Chen

Key Feature #1: A Reliable Improvement Initial Position Final Position Elevator for reaching yellow balls Walls removed to show inner workings small gears rotate against track Large gears mesh with each other so lifting force is equal on both sides of robot Jason Chen

Key Feature #2: Pivoting Arms Jason Chen

Key Feature #2: Pivoting Arms ●Pulling from top ●Requires less accuracy ●One geared motor ●Compact Design ●Simple ●One gear drives all Jason Chen

Key Feature #3: Drivetrain ●Front wheel friction drivetrain ●Two non-gear motors ●High gear ratio ●Medium torque ●Simple Friction drivetrain Inner workings of drive train Check out them shoes! Friction drive on front Jason Chen

Driving Around: An Analysis on the Drivetrain Left friction driveLeft friction drive schematic Jason Chen

Friction Drive: Force Analysis Given: ●Robot Weight: kg ●Distance from Rear Wheel to Center of Mass: 8.89 cm (2.5 inch) ●Distance from Front Wheel to Center of Mass: 6.35 cm (3.5 inch) Assumption: ●Quasi-Static Motion ●No Friction between acrylic and axles ●Non-geared motor does not slip ●Motor is strong enough to not stall Testing shows robot can actually push with 5.6 N! How much force can it actually output? Analysis Objective: How much force can our robot push with? Andrew Wilkinson Friction Drivetrain

Elevator Analysis: Rising Up Analysis Objective: Can one geared motor lift half our robot? Given: ●Robot Top half Weight: 0.44 kg ●Torque from motor: 0.32Nm ●Gravity: 9.81m/s^2 ●radius of gear: 0.6in=0.015m ●FS:2 Assumption: ●Energy loss to friction is negligible ●Quasi-Static analysis ●Gears do not jump Andrew Wilkinson

Final Performance Advantages: ●Easy to design and build ●Easy to maneuver ●Able to get whites on own side and yellow balls Disadvantages: ●Can’t get balls into own goal ●May accidentally knock balls to opponent’s side ●Elevator can jam sometimes Andrew Wilkinson Best Score: 10 points 4 white balls and 3 yellow balls on own side with no opponents

Robot in Action! Andrew Wilkinson