ADJUSTABLE MECHANICAL

STILTS

INTRODUCTION

1

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

GROUP MEMBERSTrent HilliardIan JuurlinkBrad PoirierMitchell Weir

SUPERVISORDr. Marek Kujath

INTRODUCTION

2

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

CURRENT STILTS:

1. Used for tasks requiring small rises in elevation

2. Difficult to get stilts on

3. Difficult to adjust

4. Difficult to pick up objects

PROBLEM

3

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

THE ORIGINAL STILTS

4

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

PROBLEM

CONCLUSION

PROBLEM

5

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

LIFTING DEVICE: THE SCISSOR LIFT

DESIGN

6

• Fabrication• Snap rings• Bushings• Spacers

• Operations• Sliders• Pivots

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

LIFTING DEVICE: THE SCISSOR LIFT

DESIGN

7

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

• 4 lockable heights

• 15 inches of extension height available

• Height from ground to foot:• Min = 8”• Max = 23”

15”

LOCKING MECHANISM:

DESIGN

8

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

“LOCKED” “UNLOCKED”

0

1 2

3

CLOSED POSITION

INTERMEDIATE POSITIONS

EXTENDED POSITION

GAS SPRING DAMPER:

DESIGN

9

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

• Purpose: to overcome friction loss

• Damper applies continuous extending force

LATERAL LEG SUPPORT:

DESIGN

10

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

• Provides lateral stability• Ankle support• Extends with top foot plate

DIMENSION VERIFICATION:

TESTING

11

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

• Several design requirements based on physical dimensions and weight

Dimension Length Base Width Max Width Max Height

Average 12” 4.25” 6.8” 23.075”

Dimension Upper Step Lower Step Closed Height Weight

Average 19.825” 15.425” 7.875” 13.8 lb

STRAIN GAUGE TESTING:

TESTING

12

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

• Strain gauge installation• DAQ and VI system• Acquires voltage readings

STRAIN GAUGE TESTING:

TESTING

13

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

0.5 1 1.5 2 2.5 3 3.50.0

0.5

1.0

1.5

2.0

2.5

3.0

Stress at Various Heights (50 lbs)

Locker Side TopLocker Side BottomNon-Locker Side

LOCATION

STR

ES

S (

MP

a)

STRAIN GAUGE TESTING:

TESTING

14

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

40 50 60 70 80 90 100 1100.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

Stress At Lowest Height

Locker Top SideLocker Bottom SideNon-Locker Side

LOAD (lbs)

STR

ES

S (

MP

a)

FINAL PRODUCT VIDEO:

TESTING

15

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

DESIGN REQ.INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

1. Stilts can be attached in the ‘collapsed’ position.

2. Stilts must be able to extend 12” above the ‘collapsed’ position height.

3. Operator can walk on stilts while in the ‘extended’ position.

4. Operator must be able to extend and contract the stilts while stilts attached to operator’s feet. 9

CONCLUSION

DESIGN REQ.

17

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

5. The weight of each stilt will not exceed 25 lbs.

6. The stilts will fit foot sizes up to size 12.

7. The stilts will be operational for a total load of 220 pounds

8. Stilts will have non slip surface on the bottom to simulate normal footwear traction.

CONCLUSION

DESIGN REQ.

18

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

9. Base of stilt will fit in 6”x14” footprint.

10.Prototype stilts will have a maximum cost of $2500

CONCLUSION

BUDGET

19

Item Total CostStilts $412.50Hardware $192.40Aluminum Plating $265.55Aluminum Flat Bars $ 27.12Aluminum Round Bar $ 4.52Steel Round Bar $ 5.51Concept Prototype $ 50.00Actuator $ 22.40Locking Mechanism $ 8.25Damper $172.40Miscellaneous $ 24.56

TOTAL $1,185.21

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

DECEMBER BUDGET $1,274.16

CONCLUSION

20

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

POSITIVE FEATURES:

• Easy to obtain sitting and standing position while wearing stilts

• Quicker to adjust heights

• Safer to pick up objects

• No external energy input

FUTURE RECOMMENDATIONS:

• Reduce weight

• Install wire-less actuator

• Tuned Damper

• Redesign lateral leg support

CONCLUSION

21

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION

QUESTIONS?

CONCLUSION

22

INTRO

DESIGN

PROBLEM

TESTING

DESIGN REQ

BUDGET

CONCLUSION