Detailed Design Phase Review: P14415 Patrick Morabito John
Wilson Michael Coffey Nathan Conklin Samuel Svintozelsky
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Agenda Requirements Review Prior Design 1 Design 1 Design 2
Test Plan Risks Moving Forward
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Customer Requirements
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Engineering Requirements
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Functional Decomposition Upper Level
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Functional Decomposition Mid Level
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Functional Decomposition Mid Level
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Functional Decomposition Mid Level
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Functional Decomposition Mid Level
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Functional Decomposition Sub System level
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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)
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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
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Design 1 - Vacuum forming at R.I.T
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Design 1 - Plastic Material Selection Material Selected: HDPE
Acrylic: Brittle Polycarbonate: Expensive relative to HDPE (2x the
cost for most sheets) ABS: Poor UV resistance
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Design 1 - Selected Design
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Design 1 -Assembly Drawing
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Design 1 -Lid Assembly Drawing
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Design 1 - Mold
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Design 1 -Mold Drawing
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Design 1 -Mold Assembly Drawing
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Design 1 - Rebar Design
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Design 1 - Rebar Length Optimization
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Design 1 - Proof of CR/ER Overview
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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)
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Design 1 - Analysis Assumptions Rebar supported by edge of hole
Load applied across 4in diameter circle Modified Goodman Failure
Theory Rebar is hot-rolled
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Design 1 - Ansys Analysis - Stress 270lbs
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Design 1 - Ansys Analysis - Displacement 270lbs
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Design 1 - Ansys Analysis - Stress 120lbs
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Design 1 - Ansys Analysis - Displacement 120lbs
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Design 1 - Ansys Analysis - Stress 270lbs
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Design 1 - Ansys Analysis - Displacement 270lbs
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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 Wont Fail Actual Design Stronger: Loading Distributed by
Plastic & Ribbing
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Design 1 - Proof of CR/ER: Dimensional
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(.61m)
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Design 1 - Proof of CR/ER: Dimensional (.23m) (.15m)
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Design 1 - Proof of CR/ER: Costs
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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 - 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
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Design 1 - Estimated Process Time Approximately 66 minutes
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Design 1 - Proof of CR/ER: Static coefficient of friction
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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
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Design 1 - Additional Customer Requirement: Possible Shelter
Attachment
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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)
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Design 2: Deck-Loo - Overview Design 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
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Design 2 - Material Selection 100% Recycled High Density
Polyethylene High Ultimate Strength Excellent environmental stress
crack resistance High Ductility
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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
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Design 2 - Prototype
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Design 2 - Proof of CR/ER Overview
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Main Concern is deflection Deflection between supports
Deflection of supports What is comfortable?
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Design 2 - Proof of CR/ER Overview Deflection between supports
Deflection of Supports
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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
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Design 2 - Proof of CR/ER Overview
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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 - Summary Cost in lots of 1000: $40.86 Weight per
base: 22.9lbs Worst case deflection:.44in Simple Construction
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Test Plan
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Highlighted Risks Risks 1.Not adoptable: high cost 1.Prototype
fails tests 1.Unable to manufacture in Haiti 1.Unacceptable
deflection Mitigation Strategy 1.Optimize cost through iteration
2.Modify design accordingly 1.Manufacture in the US 1.Increase the
number/material of ribs
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Limitations On campus manufacturability: machine may be unable
to form 1/4in sheets Advanced deadlines in MSDII Mold making
capabilities Shipping capabilities
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Future Project Recommendations Reiterate with only vacuum
formed plastic, without any added supports o Work with Faro
Industries Reiterate with a focus on recycled materials
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Future MSD Recommendations Less lecture content early on and
more work time 15 minutes for Subject Matter Expert meetings is
much too short
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Learning Experience Importance of project planning and
documentation Iterative design process
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MSDII Critical Path and Milestones
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Moving Forward Tasks Determine mold making capabilities Order
raw materials Manufacture mold Assemble Prototypes
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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