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Alpha 6.5: The Great Alpha 6.5: The Great Moonbuggy Race 2006Moonbuggy Race 2006

Russell AlbertsRussell AlbertsScott CollScott Coll

Haison NguyenHaison NguyenJason ZaloudekJason Zaloudek

Sponsored bySponsored by::CBU Department of Mechanical CBU Department of Mechanical

EngineeringEngineering

Faculty AdvisorsFaculty Advisors::Dr. Bernard Beard, Ph.D.Dr. Bernard Beard, Ph.D.

Dr. Paul Shiue, Ph.D.Dr. Paul Shiue, Ph.D.

March 18th, 2006

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Presentation OverviewPresentation Overview

Race specificsRace specifics

Design requirementsDesign requirements

Vehicle improvementsVehicle improvements

Testing overviewTesting overview

Final design evaluationFinal design evaluation

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The Great Moonbuggy Race The Great Moonbuggy Race Entrants must “design a vehicle that addresses Entrants must “design a vehicle that addresses

a series of engineering problems similar to a series of engineering problems similar to problems faced by the original Moonbuggy problems faced by the original Moonbuggy team.”team.”

Vehicles will be human powered and carry two Vehicles will be human powered and carry two drivers over a half-mile of simulated lunar terrain drivers over a half-mile of simulated lunar terrain including "craters", rocks, "lava" ridges, inclines including "craters", rocks, "lava" ridges, inclines and "lunar" soil.and "lunar" soil.

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The CourseThe Course

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Design RequirementsDesign Requirements

Competition rules provide Competition rules provide the design requirements the design requirements of the vehicleof the vehicle

Must fit inside 4’ cube in Must fit inside 4’ cube in “stowed” configuration“stowed” configuration

No wider than 4’ in No wider than 4’ in operational configurationoperational configuration

Maximum turning radius Maximum turning radius of 15’of 15’

Minimum passenger Minimum passenger ground clearance of 15”ground clearance of 15”

Drivers must carry vehicle Drivers must carry vehicle 20’ unassisted20’ unassisted

Must be equipped with Must be equipped with simulated mission simulated mission equipment equipment

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Alpha 6 Lunar Roving VehicleAlpha 6 Lunar Roving Vehicle

Designed as proof-of-Designed as proof-of-concept vehicle to concept vehicle to navigate the lunar navigate the lunar surfacesurface

A human powered A human powered vehicle (HPV)vehicle (HPV)

Competed Competed successfully in successfully in NASA’s 2005 Great NASA’s 2005 Great Moonbuggy RaceMoonbuggy Race

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Alpha 6.5 Lunar Roving VehicleAlpha 6.5 Lunar Roving Vehicle

Redesign of the Alpha Redesign of the Alpha 6 LRV6 LRV

Eliminate previous Eliminate previous critical design failurescritical design failures

Transmission mounting Transmission mounting failurefailure

Difficult steering designDifficult steering design

Compete in the 2006 Compete in the 2006 Great Moonbuggy Great Moonbuggy RaceRace

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Major Design TasksMajor Design Tasks Steering controlSteering control

Steering links redesignedSteering links redesigned New driver controls New driver controls

improve ease of operationimprove ease of operation DrivetrainDrivetrain

Stronger design and built to Stronger design and built to eliminate structural failure eliminate structural failure

Durability of vehicle drive Durability of vehicle drive train improvedtrain improved

Race performanceRace performance Suspension system Suspension system

stiffened to improve stiffened to improve obstacle maneuverabilityobstacle maneuverability

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Overview of Previous Overview of Previous Suspension SystemSuspension System

The front and rear suspension are both independent The front and rear suspension are both independent systemssystems

Shock and spring combination used for dampeningShock and spring combination used for dampening Front assembly made of Chromoly steel and Front assembly made of Chromoly steel and

aluminumaluminum Upper and lower control arm (A-arm) mounts Upper and lower control arm (A-arm) mounts

spindlespindle Heim joints and ball joints link suspension Heim joints and ball joints link suspension

componentscomponents Steering system utilized pushrod mechanismSteering system utilized pushrod mechanism

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Geometry components of the Geometry components of the system reanalyzed system reanalyzed Camber and toe-outCamber and toe-out UndersteerUndersteer Affects of loadingAffects of loading

Improve suspension system Improve suspension system stabilitystability Unsteady hubsUnsteady hubs Poor dampening shocksPoor dampening shocks

Improve steering control for Improve steering control for improved driver interfaceimproved driver interface

Front assembly made of 4130 Front assembly made of 4130 Chromoly steel and aluminumChromoly steel and aluminum

Redesign of Front Suspension Redesign of Front Suspension

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Coilovers Improve Race Coilovers Improve Race PerformancePerformance

Front suspension Front suspension stiffened to improve stiffened to improve vehicle ability to vehicle ability to negotiate obstaclesnegotiate obstacles

Spring ConstantSpring Constant Old: 228 Old: 228 lbflbf//inin

New: 976 New: 976 lbflbf//inin

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Design of Wheel Hub Design of Wheel Hub New design is composed New design is composed

of three componentsof three components Hub is to be sleeved with Hub is to be sleeved with

stainless steel, which stainless steel, which serves as the bearingserves as the bearing

New hub provides ride New hub provides ride stability and precisionstability and precision

Solid one-piece design Solid one-piece design provides high structural provides high structural integrityintegrity

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Analysis of Front HubAnalysis of Front Hub

Static load multiplied by a factor of 3Static load multiplied by a factor of 3

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New Steering SystemNew Steering System

Old system uses a rotating T-Old system uses a rotating T-plate connected to solid links plate connected to solid links and a leverand a lever

Wire steering creates a system Wire steering creates a system that uses cables instead of that uses cables instead of rods or shaftsrods or shafts

steering system utilizes Heim steering system utilizes Heim joints on all linkagesjoints on all linkages Heim joints are multidirectional Heim joints are multidirectional

and more precise and more precise Implementing steering wheel Implementing steering wheel

provides more intuitive controlprovides more intuitive control Flexible wire cables adapt Flexible wire cables adapt

easily to folding frameeasily to folding frame

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Additional ModificationsAdditional Modifications

New driveshafts New driveshafts manufactured due to manufactured due to wear and tear of old wear and tear of old partsparts

CNC-machined out of CNC-machined out of heat treated stainless heat treated stainless steel and TIG welded steel and TIG welded

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Additional Modifications ContinuedAdditional Modifications Continued

Previous cantilever Previous cantilever support for seats show support for seats show signs of deflection signs of deflection

Modified circular cross Modified circular cross section and moment arm section and moment arm designed to increase designed to increase safety factorsafety factor

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Drive Train Reconstructed for Drive Train Reconstructed for Improved DurabilityImproved Durability

21 speed transmission21 speed transmission Low GearLow Gear

Torque: 357 ft lbTorque: 357 ft lb Speed: 2.0 mphSpeed: 2.0 mph

High GearHigh Gear Torque: 19 ft lbTorque: 19 ft lb Speed: 16.5 mphSpeed: 16.5 mph

Critical drive train failure Critical drive train failure prevented completion of 1 prevented completion of 1 heat in last year’s raceheat in last year’s race

Transmission mounting Transmission mounting plate redesignedplate redesigned Expected loading: 88.5 ft lbExpected loading: 88.5 ft lb

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Test PlanTest Plan

Alpha 6.5 will be more Alpha 6.5 will be more extensively tested extensively tested than past entriesthan past entries

Improved testing Improved testing sequence provides: sequence provides: Additional time for Additional time for

redesign redesign Reconstruction before Reconstruction before

competitioncompetition

Testing will exploreTesting will explore Vehicle frame Vehicle frame

strengthstrength Maximum sustainable Maximum sustainable

and operational and operational speedsspeeds

Control during Control during obstacle negotiationobstacle negotiation

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Design Verification – The “Drop” TestDesign Verification – The “Drop” Test

LRV designed to survive a 12” drop while LRV designed to survive a 12” drop while fully loaded fully loaded

Vehicle will be subjected to a fall of Vehicle will be subjected to a fall of equivalent forceequivalent force

Verifies frame designed and manufactured Verifies frame designed and manufactured strengthstrength

Verifies vehicle meets race guidelines for driver Verifies vehicle meets race guidelines for driver ground clearance ground clearance

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Design Verification – Operational Design Verification – Operational Speed TestSpeed Test

LRV designed with a maximum sustainable LRV designed with a maximum sustainable speed of 16 mphspeed of 16 mph

Design based on average human capabilityDesign based on average human capabilityMust be verified with selected driversMust be verified with selected driversMaximum sustained speed over smooth terrainMaximum sustained speed over smooth terrainOperational speed over rough terrainOperational speed over rough terrain

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Design Verification – Extreme Design Verification – Extreme SituationsSituations

The “Stair Flight” TestThe “Stair Flight” TestVerify vehicle control and strength during a Verify vehicle control and strength during a

trip down CBU’s library front staircasetrip down CBU’s library front staircaseThe “Sand Pit” TestThe “Sand Pit” Test

Will determine ability of vehicle to maneuver Will determine ability of vehicle to maneuver out of the CBU volleyball courtout of the CBU volleyball court

The “Lazy Driver” TestThe “Lazy Driver” TestTest transmission mountingTest transmission mounting

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Design Verification - RaceDesign Verification - Race

Ultimate success will be determined by Ultimate success will be determined by performance in the 13performance in the 13thth Annual Great Annual Great Moonbuggy Moonbuggy

Moonbuggy designed to give drivers the Moonbuggy designed to give drivers the best opportunity to winbest opportunity to win

Race is held on April 8, 2006 at U.S. Race is held on April 8, 2006 at U.S. Space and Rocket Center in HuntsvilleSpace and Rocket Center in HuntsvilleCome support us; you will be glad you didCome support us; you will be glad you did

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Project Goals RemainingProject Goals Remaining

Complete assembly of Alpha 6.5 Complete assembly of Alpha 6.5 transmissiontransmission

Test vehicleTest vehicle Increase driver familiarity with vehicle Increase driver familiarity with vehicle

operation under race conditionsoperation under race conditionsWin 2006 Great Moonbuggy RaceWin 2006 Great Moonbuggy Race

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QuestionsQuestions