NASA moon buggy projectNASA moon buggy project

Team Members:Team Members: Brent Brent

MorelloMorelloNicholas KapesNicholas KapesAnthony ReeserAnthony Reeser

Faculty Advisor:Faculty Advisor: Dr. Quamrul Dr. Quamrul

MazumderMazumderEngineering ScienceEngineering Science

University of Michigan-FlintUniversity of Michigan-Flint

May 1, 2007

Nicholas KapesNicholas Kapes

Brent MorelloBrent Morello Anthony ReeserAnthony ReeserDr. Quamrul MazumderDr. Quamrul Mazumder

IntroductionIntroductionOur team built a competitive moon buggy according to NASA Our team built a competitive moon buggy according to NASA specificationsspecificationsTo efficiently build a moon buggy, three main roles were To efficiently build a moon buggy, three main roles were formed, (design/project management, purchasing and formed, (design/project management, purchasing and manufacturing)manufacturing)The team’s basic functions are very separate, however they The team’s basic functions are very separate, however they end up overlapping and as a result it turns out that we all end up overlapping and as a result it turns out that we all participated in each of these roles in some way. As a result our participated in each of these roles in some way. As a result our team worked well because we were able to form structure, but team worked well because we were able to form structure, but also be flexible.also be flexible.Structure was also found by separating the moon buggy build, Structure was also found by separating the moon buggy build, into sections, such chassis, steering, etc.into sections, such chassis, steering, etc.Flexibility and design efficiency was achieved by allowing Flexibility and design efficiency was achieved by allowing manufacturing to place and purchase components onto the manufacturing to place and purchase components onto the moon buggy.moon buggy.

Baseline Plan Vs. Actual Project Baseline Plan Vs. Actual Project ProgressProgress

The baseline plan only allowed for one week for each design The baseline plan only allowed for one week for each design task (chassis, steering, etc)task (chassis, steering, etc)The actual project performance proved that manufacturing The actual project performance proved that manufacturing needed around two weeks for each design taskneeded around two weeks for each design taskIt should be noted that had manufacturing not been late that It should be noted that had manufacturing not been late that design would only be slightly late on a few of the tasksdesign would only be slightly late on a few of the tasksNumerically evaluating project timeliness is around 80% Numerically evaluating project timeliness is around 80% because 1/3 (design) + 1/3 (purchasing) + 1/6 (manufacturing) because 1/3 (design) + 1/3 (purchasing) + 1/6 (manufacturing) approximately 83%approximately 83%

Projected CostProjected CostProjected cost estimate

DescriptionQuantit

y Cost

6061-T6 Al Sq. Tubing (1.5" x 1/8" thk) 24ft

1 $184.32

1018 Steel Tubing(0.5" OD x 1/8" thk.) 12ft

1 $75.68

Cable for Brakes 2 $8.00

Bike Drive Chain 30ft 1 $30.00

4 Wheels 2 $30.00

Handle Bars w/ Hand Brakes 2 $15.00

Pedals 2 $15.00

Chain 2 $10.00

Seat 2 $10.00

Front and Rear Brakes 2 $10.00

Suspension 2 $10.00

Gearing 2 $10.00

Forks 2 $10.00

Machining - $72.00

Sheet Steel(2" x 2" x 1/4") 1 $134.00

Total $624.00

Actual CostActual CostActual project cost

Description:Quantity

: Cost:

6061-T6 Al Sq. Tubing (1.5" x 1/8" thk.) 24ft

1 $184.32

1018 Steel Tubing(0.5" OD x 1/8" thk..) 12ft

1 $75.68

Boys 20" Turbo Bike 2 $119.56

Home Depot (Misc. hardware) - $98.42

Welding - $40.00

Bike Chain 4.5 ft 6 $54.00

Bike Chain Cutting Tool 1 $9.00

University of Michigan Car Flag 1 $9.99

metal blades 1 $4.42

welding 1 $40.00

rod hot roll 1 $11.64

bric brac 1 $10.60

bearings, angle stock, idler bearings 1 $49.65

flat plate, sq tube, combo pk, hex nuts/bolts

1 $21.26

Total $728.54

Projected Cost Vs. Actual Cost Projected Cost Vs. Actual Cost (cont.)(cont.)

Our biggest cost saving success in purchasing was achieved by Our biggest cost saving success in purchasing was achieved by buying bikes from Wal-Mart, because the bikes were relatively cheap buying bikes from Wal-Mart, because the bikes were relatively cheap compared to buying all of the individual components.compared to buying all of the individual components.Another success with purchasing was that we caught a break on the Another success with purchasing was that we caught a break on the purchasing of aluminum square tubing.purchasing of aluminum square tubing.Our biggest opportunity for improvement would have been the Our biggest opportunity for improvement would have been the purchasing of the steel tubing, because it was over priced.purchasing of the steel tubing, because it was over priced.It should be noted, that we did not account for all of the It should be noted, that we did not account for all of the miscellaneous hardware (nuts, bolts, tools, etc), however the budget miscellaneous hardware (nuts, bolts, tools, etc), however the budget had enough miscellaneous charges such as machining and sheet had enough miscellaneous charges such as machining and sheet metal.metal.Numerically evaluating project cost we are roughly 16% over Numerically evaluating project cost we are roughly 16% over budget, thus we achieve an 84% meeting cost targetsbudget, thus we achieve an 84% meeting cost targets

Actual Moon Buggy Vs. Model Actual Moon Buggy Vs. Model Moon BuggyMoon Buggy

Mechanical DesignMechanical Design

150 LBF

Ra, Ma

Statics:

Cantilever beam150lbf

4ft

lb600ft4ft150lbfFLMa

150lb150lbfFR a

Mechanical Design (cont.)Mechanical Design (cont.)

4333

a

n0.2184244i12

1.25in1.25in

12

1.5in1.5in

12

bhI

150lbfM

150lbfRV

Von misses stress and safety calculation:

1.449453psi

70,000psi

σ

Sn

49453psi37132.772.7749448494483τσσσσσ

2.77psi49448psi,3712

049445

2

049445τ

2

σσ

2

σσσ,σ

371psi0.25inn0.2184244i

0.125in1.5in.6875in0.75in21

150lbf

IB

VQτ

49445psin0.2184244i

1.5inftin

12lb600ft

I

MCσ

y

2222xy

2yyx

2x

22

2xy

2

yxyx21

4

4

1.25 in

0.25 in

0.685in

The beam has a safety factor of 1.4The beam has a safety factor of 1.4

Mechanical Design (cont.)Mechanical Design (cont.)

An FEA (finite element analysis) is used in cases where the cross section An FEA (finite element analysis) is used in cases where the cross section of an object is non uniform and complex to evaluate Von Misses stress, of an object is non uniform and complex to evaluate Von Misses stress, deformation and the safety factor.deformation and the safety factor.

300lbf remote load

Restraints

FEA Statics:

Mechanical Design (cont.)Mechanical Design (cont.)

FEA is using solid mesh elements with a 0.010 inch global mesh, with a 0.005 inch small feature refinement mesh, a Jacobian mesh matrix check and smoothly meshed surfaces

FEA Mesh:

Mechanical Design (cont.)Mechanical Design (cont.)FEA Von misses stress safety calculation :

The support beam has a safety factor of 2.4, due to the edge restraintsThe support beam has a safety factor of 2.4, due to the edge restraints

Mechanical Design (cont.)Mechanical Design (cont.)FEA Deformation calculation :

The support beam has a maximum deformation in the y axis of 2.8 The support beam has a maximum deformation in the y axis of 2.8 microns, which is negligiblemicrons, which is negligible

Moon Buggy CompetitivenessMoon Buggy Competitiveness

16.6

By manually adjusting the caster to 16.6 By manually adjusting the caster to 16.6 we achieve a tighter cornering radius

By using aluminum for the frame, the moon buggy weighs under 100lbf

By making the overall frame dimensions 8ft X 4ft the moon buggy is very stable

The moon buggy performance met our design targets, thus we evaluate competitiveness as 100%The moon buggy performance met our design targets, thus we evaluate competitiveness as 100%

Competition requirements Competition requirements The moon buggy completion requirements that were the most difficult

to achieve were the 4ft cube packaging requirement and the no passenger may be below 15” from the ground.

We achieved all of the moon buggy race requirements and thus the evaluation on this section is satisfactory.

The moon buggy meets all competition requirements, thus we The moon buggy meets all competition requirements, thus we evaluate this as 100% successevaluate this as 100% success Foot pedal is the

limiting factor for the 15” ground clearance

requirementSplit in frame,

accompanied with a support block helps

achieve 4ft cube packaging requirement

Overall project EvaluationOverall project Evaluation

Evaluation Categories Performance

Cost 83%

Timing 84%

Competition requirements 100%

Competitiveness 100%

Average performance 91.75%

To completely evaluate the overall project success though To completely evaluate the overall project success though achieving the goals and tasks a numerical evaluation must take achieving the goals and tasks a numerical evaluation must take place.place.

All of the categories are equally important, so they will be All of the categories are equally important, so they will be considered to be weighted equally and percentages will be considered to be weighted equally and percentages will be assigned to cost targets, timing targets, moon buggy competition assigned to cost targets, timing targets, moon buggy competition requirements and moon buggy competitiveness goalsrequirements and moon buggy competitiveness goals .

The table below shows the evaluation for each of these categories and as you may see overall, our project ends up being a 91.75% success.