1. Senior Design Ideas Team INASAD Members: Jose Medina Joseph Leone
Andrew Merk Alex Sanders
Michael Fox

2. Agenda: Midterm recap Final design modifications Final design
Subsystem overview
Engineering analysis
Prototyping modifications 2

3. Project Topic
Fluorescent Light Changing System 3

4. Problem Statement
Hundreds 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 light
twist the bulb to unhook it
remove it
install a new light 4 4

5. Goal The 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 5 5

6. Customer Needs Operators Needs: Manager or Owners’ Needs
Minimize the use of a ladder
Operable by one person
minimal physical and mental effort
Decrease 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 injuries
Cost offset by decreased number of people and hours 6 6

7. Midterm Concept 7

8. Final Design 8

9. Post Midterm Modifications
Tilting mechanism
Safety Shield 9

10. Bulb Collecting Subsystem
Installation/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

11. Bulb Rotating Subsystem
Rotation System
Consists of:
Crescent shaped base
Spring
Pull cables
Activation gripping handle

12. Bulb Gripping Subsystem
Suction Cup Gripping System
Consists 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

13. Safety Subsystem Material Thin Polycarbonate
Flexible
See through
Polycarbonate helps balance the tool during operations 13

14. Bowing Subsystem Trapezoidal Bowing System
4 adjustable bars for stability
2, ¼ circle adjustable disks
15°-90° adjustment
1 Lever adjustment bar

15. Base/Raising and Lowering Subsystem
Tripod base
Rack and Pinion height adjustment
Allows for large and precise maneuvering
Hand crank or power drill adjustable 15

16. Normalizing Subsystem
Leveling mounts normalize tool on uneven surfaces 16

17. Types of Engineering Analysis Implemented
Material Selection
Strength of Materials
Stability During Operation
Kinematic Analysis
Spring Selection Analysis
Fatigue Analysis
Human Interface
Tolerances
Performance Analysis 17

18. Engineering Analysis to be Discussed
Material Selection
Strength of Materials
Stability During Operation
Kinematic Analysis 18

19. Material Selection Baseline weight found using Aluminum
Baseline load calculations preformed (using Al as material)
Part most likely to fail was Bowing Mechanism Locking Pin
Stress = psi x safety factor 0f 3 = psi
Used CES EduPack 2008
Parameters
Yield Stress > psi
Low Ductility
Elongation of 1020 HR steel = 36%
High Hardness
Material Chosen
Polystyrene (20% Glass Fiber)
Mention that the calculations were redone using the chosen material and will be shown later. 19

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

21. Material Selection Polystyrene (20% Glass Fiber) vs. Polystyrene
Elongation = 10-20%
Rockwell Hardness R = 75-95
Polystyrene (20% Glass Fiber)
Elongation = 1-1.3%
Rockwell Hardness R =
93.5 % decrease in elongation (lower ductility)
33.6% increase in hardness
Don’t forget to mention that the Polystyrene (20% glass fibers) was chosen over basic polystyrene even though the strength is way to high. 21

22. Strength of Materials Parts more prone to Failure Rotation shaft
Bowing mechanism lock pin
Bowing mechanism top tilt pin
Bowing mechanism bottom tilt pin
Tilt plate teeth
Adjustable tilting bar 22

23. Strength of Materials Overall results Bowing mechanism lock pin
Shear Stress experienced by part =191.8 psi
Safety Factor = 41.8 23

24. Stability During Operation
Wbase = 54.6 lbs (needed not to tip)
Wactual, base = 8.7 lbs.
Wadded to base = Wbase - Wactual, base = 45.9 lbs 24

25. Kinematic Analysis
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. 25

26. Financial Analysis Material Cost Labor/Production/Shipping Costs
$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

27. 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

28. Financial Analysis Company savings Product Payoff Rate (PPR)
$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
*( Estimates do not include savings from possible reductions in insurance cost as well as worker compensation claims.)

29. Prototype Modification
Tilt Plates
Housing Spring
Material Selection
Added Weight to Base
Pull cables replaced with fishing line hand pulled 29

30. Prototype Modification
Tilt plate side panels 30

31. Prototype Modification
Housing Springs
Due to size and strength requirements the spring need to be fabricated
Replaced with badge retracting clips 31

32. Prototype Modification
Materials
Housings and rotation sleds
High density Polyethylene
Rotation bar and Tilt adjusting bar
HR Steel
Tilt Plates
Aluminum
Tilting legs, and Rotation support Structure
PVC pipe 32

33. Prototype Modification
Replace pull cables with fishing line
Due to cost of cables ($42/cable) fishing line was substituted and will be hand pulled to create the needed motion. 33

34. Video 34

35. Future Improvements Storage Base Attachable Light
Provide base weight for stability
Would hold replacement and old bulbs
Attachable Light
Would illuminate areas of low lights as well as areas with high ceilings 35

36. Future Improvements Alignment Camera Height increase
Would provide images of the working area on a screen which would be at eye level.
Height increase
Increasing the reachable height would make the product more usable at all ceiling heights. 36

37. Fluorescent Light Changing System
INASAD
Fluorescent Light Changing System 37