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

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 ptYellow 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 drive Left friction drive schematic

Jason Chen

Friction Drive: Force Analysis

Given:● Robot Weight: 1.444 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 UpAnalysis 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 PerformanceAdvantages:

● 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 points4 white balls and 3 yellow balls on own side with no opponents

Robot in Action!

Andrew Wilkinson