P14415: Subsystem Design Review Patrick Morabito John Wilson Michael Coffey Nathan Conklin Samuel Svintozelsky

Agenda Background and Recap Information Engineering Requirement Flowdown Subsystems Proof of Concept o Prototyping o Economic Analysis Test Procedure & Risks Moving Forward

Background Information Inadequate sanitation is a major cause of preventable illnesses in children around the world. According to UNICEF, diarrhea alone causes over 1.6 million deaths in children under 5. These illnesses can easily be prevented by improving sanitation. However, cost is a major barrier limiting the adoption of sanitation in Haiti. Peter Morgan’s Arborloo is a simple latrine built over a small pit, which when filled is then moved to a new pit location. The old, filled pit then has vegetation planted on top of it, such as a fruit tree.

New Learnings Meeting with Johnny o Low-cost reaffirmed as critical constraint o Building capabilities explored Mock up build o Hole size requirement revisited o Platform size improvementsxxx

Engineering Requirements - Updates S4-Maximum squat hole diameter S8-Complexity of tools needed

Critical Requirements Recap Cost o Continuously surfaces as primary requirement Weight o Crucial to remote users Load Bearing Ability o Main functional requirement (From Engineering Requirements) ect%20Planning%20Phase/Engineering_Re quirements_14415.xls ect%20Planning%20Phase/Engineering_Re quirements_14415.xls

Highlighted Functions Guides Raw Sewage Supports Weight Separates User from the Pit Establishes Barrier Between User and Waste

Subsystems Manufacturing Process Material Selection Shape & Form

Manufacturing Processes

Materials Considered Cost Matrix Acquired Quotes for these materials are a little too costly.

Design #1 Explored Rib Design Models Built Full Scale Mockup Built Vacuum Formed Scale Model Two Directions

Design #1 Rib Design Set up 2000N Load Fixed at 4 corners Model Tensile Strength: 9.5 * 10 ^7 N/m^2 Fixed at 4 corners of base Load: 2000N Load *Refer to reports for mesh information

Design #1 Exploration

Design #1: Highlighted Beta Designs

Design 1 Rib Design Summary

Design #1 - Half Scale Model Purpose: ●Test ABS Plastic ●Test vacuum forming capabilities

Design #1 - Half Scale Model Cont.

Lessons Learned Weak/Thin Corners Poor edge draft/vacuum Strong ribs & durable top surface

Design #2 Full Scale Mockup Material Selections Cost Analysis

Design #2 Cost Analysis 1 x 6” Design o 11/16” thick o 14’ Plastic board o 10’ 2x2 ribbing o $43.7 total 10-¼ x ¼” o ¼” thick o ’ board o 10’ 2x2 ribbing o $35.66 total

Cost Analysis - Design #1 & #2 Full Scale Models

Designs #3 & #4 Not Feasible Designs Cardboard Models o Difficult to sit and stand o Scale required to cover hole required separate supporting base Better as Seats o Can easily be integrated with a bucket

Updated Risks Assessment (Technical)

Updated Risks Assessment (Project)

Updated Risks Assessment (Team)

Test Plan - Revisited

Updated Project Plan

Key Decisions from Subsystem Phase Design 1: Two Directions o Plastic Ribbing & Supports o Recycled/Repurposed Material Design 2: “Local Industry” Designs 3 & 4: No Longer Full Designs o Possible Seat Integration Possible Manufacturing Processes o Vacuum Forming o Rotational Molding o “Kit” o Recycled

Moving Forward - Next Phase Design 1: Repurposed Materials Method Design 2: Support Structure Lid Designs Seats (Upgradable) Cleanability

Questions?