1. Tilt N’ Store Design Analysis

2. Chain Hoist Support
Anchor
Frame
Frame Leg
Bike Support
Arm

3. Key Question:
What Factor of Safety do we get assuming the Tilt N’ Store is built from the materials proposed in the Bill of Materials? Or will the Tilt N’ Store survive if built with the materials suggested?

4. Tilt N’ Store - Arm L1 72in b1 1in h1 3in t1 0.120in c1 h1/2 d1
Figure 1: Free Body Diagram of Arm
Table 1: Design Parameters
Figure 2: Mechanical Advantage From Chain Hoist (MA = 25)

5. Tilt N’ Store - Arm Conclusions: Normal Stress:
Figure 3: Shear Diagram of Arm
Figure 4: Bending Moment Diagram of Arm
Conclusions:
Normal Stress:
The Maximum Normal Stress due to Bending on the arm has a magnitude of 25,382 psi
The Factor of Safety given this Normal Stress is 1.42
Shear Stress:
The Maximum Shear Stress on the arm has a magnitude of 1,000 psi
The Factor of Safety give this Shear Stress is 33.7

6. Tilt N’ Store - Chain Hoist Support
Figure 5: Free Body Diagram of Chain Hoist Support b2
3in h2 t2
1/8in c2
h2/2 d2
7in
Table 2: Design Parameters

7. Tilt N’ Store – Chain Hoist Support
Figure 6: Shear Diagram of Chain Hoist Support
Figure 7: Bending Moment Diagram of Chain Hoist Support
Conclusions:
Normal Stress:
The Maximum Normal Stress due to Bending on the support has a magnitude of 14,513 psi
The Factor of Safety given this Normal Stress is 2.48
Shear Stress:
The Maximum Shear Stress on the support has a magnitude of psi
The Factor of Safety give this Shear Stress is 38

8. Tilt N’ Store - Frame Leg
Figure 8: Free Body Diagram of Frame Leg b3
3in h3 t4
1/8in c4
b3/2 d1
1in
Table 3: Design Parameters

9. Tilt N’ Store – Frame Leg
Figure 9: Shear Diagram of Frame Leg
Figure 10: Bending Moment Diagram of Frame Leg
Conclusions:
Normal Stress:
The Maximum Normal Stress due to Bending on the frame leg has a magnitude of 0 psi
The Factor of Safety given this Normal Stress is Infinity
Shear Stress:
The Maximum Shear Stress on the frame leg has a magnitude of 0 psi
The Factor of Safety give this Shear Stress is Infinity

10. Tilt N’ Store - Anchor b4 3in h4 t5 1/8in t6 L2 12in L3 24in
Figure 11: Free Body Diagram of Anchor b4
3in h4 t5
1/8in t6 L2
12in L3
24in
Table 4: Design Parameters

11. Tilt N’ Store – Anchor (Vertical Support)
Figure 12: Shear Diagram of Anchor (Vertical Support)
Figure 13: Bending Moment Diagram of Anchor (Vertical Support)
Conclusions:
Normal Stress:
The Maximum Normal Stress due to Bending on the support has a magnitude of 1,712 psi
The Factor of Safety given this Normal Stress is 21
Shear Stress:
The Maximum Shear Stress on the support has a magnitude of 443 psi
The Factor of Safety give this Shear Stress is 76

12. Tilt N’ Store – Anchor (Horizontal Support)
Figure 14: Shear Diagram of Anchor (Horizontal Support)
Figure 15: Bending Moment Diagram of Anchor (Horizontal Support)
Conclusions:
Normal Stress:
The Maximum Normal Stress due to Bending on the support has a magnitude of 3,108 psi
The Factor of Safety given this Normal Stress is 11.6
Shear Stress:
The Maximum Shear Stress on the support has a magnitude of 1,658 psi
The Factor of Safety give this Shear Stress is 20

13. Tilt N’ Store - Frame L4 144”-b1 c3 h3/3 t3 1/8in
Figure 16: Free Body Diagram of Anchor L4
144”-b1 c3
h3/3 t3
1/8in
Table 5: Design Parameters

14. Tilt N’ Store – Frame Conclusions: Normal Stress:
Figure 17: Shear Diagram of Frame
Figure 18: Bending Moment Diagram of Frame
Conclusions:
Normal Stress:
The Maximum Normal Stress due to Bending on the frame has a magnitude of 13,530 psi
The Factor of Safety given this Normal Stress is 2.66
Shear Stress:
The Maximum Shear Stress on the frame has a magnitude of 835 psi
The Factor of Safety give this Shear Stress is 40.28

15. Tilt N’ Store – Pins
How large do the pins at the joints need to be in order to hold the weight?
The Maximum Shear Stress due to the reaction forces at the pins was calculated to be 4800psi using a steel bar with a 0.25” diameter. This yields a Factor of Safety of 7.
The Bearing Stress on the thinner beam is calculated to be 3000psi. A subject matter expert said a more in-depth approach to calculating bearing stress can be found in some more advanced literature.
Can we use a dry bearing or do we need to grease the pin?
After discussing this point with a subject matter expert, he recommended that we use a dry bearing. He believed the weight our system would encounter would not be enough to require a greased bearing.
He also recommended using bolts for cheaper cost and easier construction (More analysis to follow on the grade of bolt that needs to be selected). The evolution of the pins started at door hinges  self-fabricated gate hinges  Welded Rod  Bolts. t
Ry1 d D

16. Key Questions Answered:
What Factor of Safety do we get assuming the Tilt N’ Store is built from the materials proposed in the Bill of Materials? – Answered in previous slides
How large do the pins at the joints need to be in order to hold the weight?
-Answered in previous slides
Based on the material, can we use 3 beams?
Yes, the Factor of Safety is fine even with an exaggerated load.
What thickness do the steel walls need to be?
The analysis above was run assuming the arms have a wall thickness of 0.120” and the rest of the frame has a thickness of 1/8”. Both resulted in acceptable Factors of Safety
How much force do the safety ropes need to hold?
One safety rope holding a 100lb beam with 500lbs of Bikes at the end will need to hold ~2400lbs when attached at a 45 degree angle 2 feet from the pivot joint.
Rope
45deg
2ft W
Bike