team inasad members: jose medina joseph leone andrew merk alex sanders michael fox

Team INASAD

Members: Jose Medina Joseph

LeoneAndrew Merk Alex

SandersMichael Fox

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Midterm recapFinal design

modificationsFinal designSubsystem overviewEngineering analysisPrototyping modifications

Agenda:

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Project TopicFluorescent Light Changing System

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Problem StatementHundreds to thousands of fluorescent light bulbs in an

average building. Changing bulbs is dangerous and time consuming

To improve this process, an instrument which from the ground could:

grasp the lighttwist the bulb to unhook itremove it install a new light

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GoalThe overall goal of this project is to create a

tool that:

Simplifies the removing and installation of fluorescent light bulbs

Makes the overall task safer

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Customer NeedsOperators Needs:

Minimize the use of a ladderOperable by one person

minimal physical and mental effortDecrease the time to change a bulb by hand Reliable and easily maintained

Manager or Owners’ Needs Limits number of employees and time needed to perform

the task Decrease injuriesCost offset by decreased number of people and hours

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Midterm Concept

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Final Design

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Post Midterm ModificationsTilting mechanism

Safety Shield

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Bulb Collecting SubsystemInstallation/Removal System

Consists of: 2 U-shaped areas for bulb to fit

1 for bulb removal 1 for bulb installation

Using a cam, spring and pull cable the system will rotate 90 degrees

Simplifies removal and installation process

Improves alignment

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Bulb Rotating SubsystemRotation System

Consists of: Crescent shaped base Spring Pull cables Activation gripping handle

Suction Cup Gripping SystemConsists of:

3 suction cups for each sled Suction cups attached to a crescent

shaped base

Force needed to rotate a light bulb into removal position is 2.8 lbs.

Each suction cup can with stand an average force for 1.7 lbs

3 suction cups = 5.1 lbs of force

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Bulb Gripping Subsystem

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Safety SubsystemMaterial

Thin Polycarbonate

Flexible See through

Polycarbonate helps balance the tool during operations

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Trapezoidal Bowing System4 adjustable bars for

stability2, ¼ circle adjustable disks

15°-90° adjustment1 Lever adjustment bar

Bowing Subsystem

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Tripod baseRack and Pinion

height adjustmentAllows for large and

precise maneuveringHand crank or power

drill adjustable

Base/Raising and Lowering Subsystem

Normalizing SubsystemLeveling mounts

normalize tool on uneven surfaces

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Types of Engineering Analysis Implemented1. Material Selection 2. Strength of Materials 3. Stability During Operation 4. Kinematic Analysis 5. Spring Selection Analysis 6. Fatigue Analysis 7. Human Interface 8. Tolerances 9. Performance Analysis

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Engineering Analysis to be Discussed1. Material Selection 2. Strength of Materials 3. Stability During Operation 4. Kinematic Analysis

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Material Selection Baseline weight found using AluminumBaseline load calculations preformed (using Al as

material) Part most likely to fail was Bowing Mechanism Locking Pin Stress = 441.3 psi x safety factor 0f 3 = 1323.8 psi

Used CES EduPack 2008 Parameters

Yield Stress > 1323.8 psi Low Ductility

Elongation of 1020 HR steel = 36% High Hardness

Material Chosen Polystyrene (20% Glass Fiber)

Polystyrene (20% Glass Fiber)Yield strength (elastic limit) 8 kpsi (55.2 MPa)Tensile strength 10 kpsi (69 MPa)Elongation 1 - 1.3 %Hardness - Rockwell R 113 – 125Fatigue strength at 107 cycles 3.9 kpsi (26.6 MPa)Overall cost of Polystyrene material for tool body $58

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Material Selection

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Material SelectionPolystyrene (20% Glass Fiber) vs. Polystyrene

Polystyrene Elongation = 10-20% Rockwell Hardness R = 75-95

Polystyrene (20% Glass Fiber) Elongation = 1-1.3% Rockwell Hardness R = 113-125

93.5 % decrease in elongation (lower ductility)33.6% increase in hardness

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Strength of Materials Parts more prone to Failure

1. Rotation shaft 2. Bowing mechanism lock pin 3. Bowing mechanism top tilt pin 4. Bowing mechanism bottom tilt pin 5. Tilt plate teeth 6. Adjustable tilting bar

Overall results Bowing mechanism lock pin

Shear Stress experienced by part =191.8 psi Safety Factor = 41.8

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Strength of Materials

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Wbase = 54.6 lbs (needed not to tip) Wactual, base = 8.7 lbs. Wadded to base = Wbase - Wactual, base = 45.9 lbs

Stability During Operation

Distance the sled needs to travel to rotate the bulb 90 °S=Rθ

S=arc length R=radius of race θ=90°

S=2.3 in.

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Kinematic Analysis

Financial Analysis Material Cost

$256 (based on store prices) 15-20% reduction in cost from mass

production would be assumed

Labor/Production/Shipping Costs $ 60(approximate)

Total Cost $316 (based on store prices)

Sales Price $998

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Financial Analysis Georgia Institute Of

Technology Labor Cost $35/hour

Product Time Savings 30%

Company Savings $11.67/hr $0.391/light bulb

≈ 2 minutes to change a light bulb

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Financial Analysis Company savings

$11.67/hr. $0.391/light bulb

≈ 2 minutes to change a light bulb

Product Payoff Rate (PPR) *PPR = 85.5 hrs. (about 2 work

weeks) *PPR = 2,553 Light bulbs

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*( Estimates do not include savings from possible reductions in insurance cost as well as worker compensation claims.)

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Prototype ModificationTilt PlatesHousing SpringMaterial Selection

Added Weight to BasePull cables replaced

with fishing line hand pulled

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Tilt plate side panels

Prototype Modification

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Housing SpringsDue to size and strength

requirements the spring need to be fabricated

Replaced with badge retracting clips

Prototype Modification

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MaterialsHousings and rotation sleds

High density PolyethyleneRotation bar and Tilt

adjusting barHR Steel

Tilt PlatesAluminum

Tilting legs, and Rotation support Structure

PVC pipe

Prototype Modification

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Replace pull cables with fishing lineDue to cost of cables

($42/cable) fishing line was substituted and will be hand pulled to create the needed motion.

Prototype Modification

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Videohttp://helix.gatech.edu/Classes/

ME4182/2009S1/projects/Team_INASAD/gallery.html

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Future Improvements1. Storage Base

Provide base weight for stability Would hold replacement and old bulbs

2. Attachable Light Would illuminate areas of low lights as well

as areas with high ceilings

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Future Improvements3. Alignment Camera

Would provide images of the working area on a screen which would be at eye level.

4. Height increase Increasing the reachable height would

make the product more usable at all ceiling heights.

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INASADFluorescent Light Changing System