Download - Detailed Design Phase Review: P14415
Detailed Design Phase Review: P14415
Patrick Morabito John Wilson Michael CoffeyNathan ConklinSamuel Svintozelsky
Agenda• Requirements Review• Prior Design 1• Design 1• Design 2• Test Plan• Risks• Moving Forward
Customer Requirements
Engineering Requirements
Functional DecompositionUpper Level
Functional DecompositionMid Level
Functional DecompositionMid Level
Functional DecompositionMid Level
Functional DecompositionMid Level
Functional DecompositionSub System level
Design 1 - Prior Design Iteration
• Overly Conservative Analysis Model
• Failed • Worst Case Loading
(6180psi): +150% of Ultimate Strength (4100psi)
• Value too high to justify moving forward
• (Arrows denote failure location)
Design 1 - Manufacturing Process
• Full production and prototype tooling costs for large dimension (32in x 32in) base too expensive to proceed.
• Prototype costs range in the $8,000 + range
• Full production run costs for lots of 100 = $50.00 o still relatively large for simplicity of
part• Have contacted Faro Industries for
additional vacuum forming support. Possibility to re-quote prototype using wooden mold. *Discussed in more detail later in powerpoint
• Wooden mold for large dimension part could cost ~ $3,000
Design 1 - Vacuum forming at R.I.T
Design 1 - Plastic Material SelectionMaterial Selected: HDPE
Acrylic: Brittle
Polycarbonate: Expensive relative to HDPE (2x the cost for most sheets)
ABS: Poor UV resistance
Design 1 - Selected Design
Design 1 -Assembly Drawing
Design 1 -Lid Assembly Drawing
Design 1 - Mold
Design 1 -Mold Drawing
Design 1 -Mold Assembly Drawing
Design 1 - Rebar Design
Design 1 - Rebar Design
Design 1 - Rebar Length Optimization
Design 1 - Rebar Length Optimization
Design 1 - Proof of CR/ER Overview
Design 1 - Proof of CR/ER: Strength
(Insert link to detailed calculations here?)
29600 Cycles => ~3.86 years(Family of 7, 3 times per day, 365 days a year)
Design 1 - Analysis Assumptions• Rebar supported by edge of hole• Load applied across 4in diameter circle• Modified Goodman Failure Theory• Rebar is hot-rolled
Design 1 - Ansys Analysis - Stress 270lbs
Design 1 - Ansys Analysis - Displacement 270lbs
Design 1 - Ansys Analysis - Stress 120lbs
Design 1 - Ansys Analysis - Displacement 120lbs
Design 1 - Ansys Analysis - Stress 270lbs
Design 1 - Ansys Analysis - Displacement 270lbs
Design 1 - Analysis Summary• Average Loading (120lbs): Infinite Life & No
Yield• High Loading (270lbs): Finite Life (29600
cycles) & No Yield; 3.86 years• Largest Unsupported Plastic Section Won’t
Fail• Actual Design Stronger: Loading Distributed
by Plastic & Ribbing
Design 1 - Proof of CR/ER: Dimensional
Design 1 - Proof of CR/ER: Dimensional
(.61m)
Design 1 - Proof of CR/ER: Dimensional
(.23m)
(.15m)
Design 1 - Proof of CR/ER: Costs
Design 1 - Cost Breakdown: Shipping
Assumptions:-One day storage before
loading and after unloading (2 days total)
-Weight does not affect shipping cost
-Arborloo will be assembled in Haiti (i.e. only raw material is shipped)
Cost to ship:
20’ Shipping Container Dimensions:
Design 1 - Cost Breakdown Cont.
Material Cost:
Shipping Cost:
Labor Cost:
Design 1 - Proof of CR/ER: Weight
Design 1 - Proof of CR/ER: Assembly
● Finished Purchased Product: Does not require on-site assembly● On-site installation requires the removal of surrounding surface to
allow the product to sit in the ground
● No complex tools required at use location
Design 1 - Estimated Process TimeApproximately 66 minutes
Design 1 - Proof of CR/ER: Static coefficient of friction
Design 1 - Proof of CR/ER: Misc
● Ease of Cleaning: Detachable lid, non porous material, lightweight dumpable design, smooth surface
● Aesthetically Pleasing: Pending focus group review
Design 1 - Additional Customer Requirement: Possible Shelter Attachment
Design 1 - Summary
• Cost in lots of 1000: $23.86
• Weight per base: 22.2lbs
• Infinite life for rebar at average load (120lbs)
• 3.86 years for rebar at high load (270lbs)
Design 2: Deck-Loo - OverviewDesign Advantages
● Robust material○ Designed for use outdoor○ Designed as walking surface
● Simple Construction○ Pre cut pieces can be assembled
with screws alone
● Lightweight Design○ 22.9 lbs
Design 2 - Material Selection100% Recycled High Density Polyethylene
• High Ultimate Strength
• Excellent environmental stress crack resistance
• High Ductility
Design 2 - Manufacturing Process• Delivery of “Kitted” plastic lumber to
village craftsman
• Assembled by screwing lumber together
• Purchased in village and carried to use sight fully assembled
Design 2 - Prototype
Design 2 - Proof of CR/ER Overview
Design 2 - Proof of CR/ER Overview
Main Concern is deflection• Deflection between supports
• Deflection of supports
• What is comfortable?
Design 2 - Proof of CR/ER Overview
Deflection between supports
Deflection of Supports
Design 2 - Proof of CR/ER Overview
This analysis is conservative because of point load assumption, so deflection should be less
Based on current Haitian sanitation solutions, the team agrees this deflection is sufficient. However, we have ordered more supports than needed, so we can adjust if necessary
Design 2 - Proof of CR/ER Overview
Design 2 - Proof of CR/ER Overview
Design 2 - Proof of CR/ER Overview
Design 2 - Proof of CR/ER Overview
Design 2 - Cost Breakdown: Shipping
Assumptions:-One day storage before
loading and after unloading (2 days total)
-Weight does not affect shipping cost
-Arborloo will be assembled in Haiti (i.e. only raw material is shipped)
Cost to ship:
20’ Shipping Container Dimensions:
Design 2 - Cost Breakdown Cont.
Material Cost:
Shipping Cost:
Labor Cost:
Design 2 - Summary
• Cost in lots of 1000: $40.86
• Weight per base: 22.9lbs
• Worst case deflection: .44in
• Simple Construction
Test Plan
Test Plan
Highlighted RisksRisks
1. Not adoptable: high cost
2. Prototype fails tests
3. Unable to manufacture in Haiti
4. Unacceptable deflection
Mitigation Strategy1. Optimize cost through
iteration2. Modify design accordingly
3. Manufacture in the US
4. Increase the number/material of ribs
Limitations• On campus manufacturability: machine
may be unable to form 1/4in sheets• Advanced deadlines in MSDII • Mold making capabilities• Shipping capabilities
Future Project Recommendations• Reiterate with only vacuum formed
plastic, without any added supportso Work with Faro Industries
• Reiterate with a focus on recycled materials
Future MSD Recommendations• Less lecture content early on and more
work time• 15 minutes for Subject Matter Expert
meetings is much too short
Learning Experience• Importance of project planning and
documentation• Iterative design process
MSDII Critical Path and Milestones
Moving ForwardTasks• Determine mold making capabilities• Order raw materials• Manufacture mold• Assemble Prototypes
Acknowledgements• A big thank you to Sarah, Pedro, Kevin,
Johnny, Dr. Thorn, Dr. Lam, Dr. Debartolo, and Dr. Boedo, Dr. Humphrey, and all other parties that have assisted us
Questions?