Three Legs are Better than Four

Joseph CaluzaAerospace Engineering

Daniel KaminskiMechanical Engineering

Tyler StearsEnvironmental Engineering

ℜSDRSℜΧ

Tyler Stears

But First…

…DEPLOY!!!!!!Tyler Stears

Tyler Stears

Project Objective

• Simplicity: As a team of three, we did not want a risky design.

• Reproducibility: Controlling the robot is kept simple with just two degrees of freedom.

• Exceptional Fabrication: Implementation of Design for Manufacture methods

Tyler Stears

Lock and Load

• The shim stock component acts as a high-powered spring to deploy the robot arm. The small rubber band aids in auxiliary deployment of the arm and deploys the reaping fork.

Tyler Stears

Compressed Shim stock

Stretched small rubber band

Small rubber band puts fork under tension

On Your Mark’s, Get Set…

Daniel Kaminski

….RELEASE!!

Fork slips out from friction drive shaft when the wheel make a small rotation

Small rubber band aids the shim stock pin to lock in place

Decompressing Shim stock

Fork rotates out of position

Fork held in place by rubber band

Shim locks into rear arm notch

Daniel Kaminski

Reaper’s Deployment

• The shim reverts to its original straight position to release the Reaper.

Sliding Screw locks into notch in the slide

Arm Locks into place with linear slider with help of rubber band

Shim fixed on upper portion of arm

Notch locks the arm in place

Rubber band tension holds pin in notch

Rubber band keeps fork forward

Daniel Kaminski

Parts of the Design Process: Design for Manufacturability

Slots

Universal width to interchange forks

Clearance Holes

Rotating WheelFore arm

Daniel Kaminski

Fork Evolution

Daniel Kaminski

Friction Driven

Joseph Caluza

You’ll Get a Kick Out of This

How to get the tree monkeys?

Get Lifted!!

Kick slips out and reaper claims ground monkeys

Get Un-lifted!!

Joseph Caluza

Wheel Torque Analysis

Tfriction = A*(umg/A)*r = umg*rTfriction = (0.8)(0.186 kg)(9.81m/s^2)(0.0813m) = 0.119 N*mTfriction needed = F.S. * Tfriction = 1.5 * 0.119 N*m = 0.179 N*mActual Torque Generated = (.75N)*(.235m) = 0.176 N*m

Motor FBD Friction Normal FBD Wheel FBD

Mass of robot arm with max load of three monkeys (m) = 0.186 kgRadius of Circle Piece (r) = 3.2 in = 0.0813 mCoefficient of friction of acrylic on acrylic (u) = 0.8Factor of Safety = 1.5 Note: Lubricant reduces coefficient

friction value

Joseph Caluza

ℜSDRSℜ Χ in Action

Scores 60 points max!!Reaping occurs in 20-30 seconds

Joseph Caluza