P14417: B9 Plastics - Particle FilterDetailed Design Review
Dan Anderson / Thomas Heberle / Perry Hosmer / Karina Roundtree / Kelly Stover
December 10, 2013
Agenda
• Problem Definition (5 minutes)
• Updated Design and Bill of Materials Justification (15
minutes)
• Assembly Procedure (5 minutes)
• Technical Analysis of Design (20 minutes)
• Test Plans (20 minutes)
• Project Management (10 minutes)
Problem Definition
Problem Statement
Current State:
• In order to use the Better Water Maker (BWM) users must first pour the water through a
cloth before being treated.
Desired State:
• The device should clear particles from water to allow the BWM to operate more effectively.
• The device should be simple to use and operable by both women and children.
Project Goals:
• Analyze the design selected by P13418
• Decrease Turbidity and Total Suspended Solidso Improve the effectiveness of the Better Water Maker
Notable Constraints:
• Must be usable by both women and children
• Only locally available materials may be consumed
• Must not negatively impact the smell and taste of water
Project Scope & Deliverables
• Project Scopeo Eliminate particles greater than 5 microns in size
o Produce a design that is economically viable for use in developing countries
o Design the device to be reusable, and use only consumable parts that are
locally available
• Deliverables to dateo Functional prototype
o Bill of Materials
o Design Drawings
o Assembly and manufacturing plan
o Test plan and results
Customer RequirementsCustomer
Requirement
Category Description Importance
CR1 Ease of Use Easy to prepare for use 9
CR2 Ease of Use Lightweight for user transport / shipping 3
CR3 Ease of Use Has a minimal startup period 3
CR4 Ease of Use Operates using only naturally available energy 9
CR5 Economics Inexpensive 9
CR6 EconomicsUsable by a family of 5, for 2-5 years without full replacement
9
CR7 EconomicsRequires no consumables for operation (other than cheap and locally available materials)
9
CR8Functionality
Improves UV transmission 9
CR9Functionality
Decreases turbidity 9
CR10Functionality
Decreases total suspended solids 9
CR11Functionality
Does not negatively affect taste 3
CR12 Safety Does not negatively affect safety of water 9
CR13Functionality
Filters enough water for a family of 5, daily 3
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Updated Design and Bill of Materials
Updated Drawing – CAD Drawing
Updated Drawing – Exploded BOM
1
2
4
3
No. Item Vendor
1 Bottomless bucket The Cary Company2 Lid The Cary Company
3 5 Micron Mesh Macro Specialty Steel
4 Bucket The Cary Company
Bottomless Bucket
Bottomless Bucket
• Bucket in BOM chosen was inexpensive
• Most buckets would work
No. Item Vendor Vendor item number/description
Qty Price per item
price per unit
tools to make
1 Bottomless bucket The Cary Company 57WCU5 1.00 2.97 2.97 saw to cut out hole
Lid
Lid
• Matches bucket bottom, reusable
• Inexpensive
No. Item Vendor Vendor item number/description
Qty Price per item
price per unit
tools to make
2 Lid The Cary Company 57WCUP 1.00 1.47 1.47 drill for holes
5 Micron Mesh
5 Micron Mesh
• Stainless steel- limits corrosion
• Material often used in filters
No. Item VendorVendor item
number/descriptionQty
Price per item/Sq
ft
price per unit
tools to make
3 5 Micron Mesh Macro Specialty Steel200x1400 Twill Dutch
Weave 316ss1.00 11.75 6.32 cut to size
Bucket
Bucket
• Inexpensive
• 5 gallon deemed a good size
• Same as bottomless bucket
No. Item Vendor Vendor item number/description
Qty Price per item
price per unit
tools to make
4 Bucket The Cary Company 57WCU5 1.00 2.97 2.97 N/A
Spacer
Rod
Spacer and Rods
• Used to seal in mesh in assembly and to provide space
between mesh and lid
No. Item VendorVendor item
number/descriptionQty
Price per item/Sq
ft
price per unit
tools to make
6 Spacers N/AMade from cut out
portion of bottomless 44.00 0.00 0.00 Some type of shear to cut
7 Rods N/AMade from cut out
portion of bottomless bucket
20.00 0.00 0.00 Some type of shear to cut
Indented BOMNo. Item Vendor
Vendor item number/description
QtyPrice per item/Sq
ft
price per unit
tools to make
1 Bottomless bucket The Cary Company 57WCU5 1.00 2.97 2.97 saw to cut out hole2 Lid The Cary Company 57WCUP 1.00 1.47 1.47 drill for holes
3 5 Micron Mesh Macro Specialty Steel200x1400 Twill Dutch
Weave 316ss1.00 11.75 6.32 cut to size
4 Bucket The Cary Company 57WCU5 1.00 2.97 2.97 N/A
5 Nylon Brush Home DepotQuickie Original Iron
Handle Curved Plastic Scrub Brush
1.00 2.19 2.19 N/A
6 Spacers N/AMade from cut out
portion of bottomless 44.00 0.00 0.00 Some type of shear to cut
7 Rods N/AMade from cut out
portion of bottomless bucket
20.00 0.00 0.00 Some type of shear to cut
total 15.92
Assembly Procedure
Technical Analysis of Design
Mesh Corrosion
• Stainless steel is in a family of alloy steels containing a minimum of
10.5% chromium. All stainless steels have a higher resistance to
corrosion than their mild steel counterparts.
• This resistance to attack is due to the naturally occurring chromium-rich
oxide film formed on the surface of the steel.
• The film is rapidly self-repairing in the presence of oxygen. Damage by
abrasion, cutting or machining is quickly repaired.
Stress Analysis
• Establisho Contact Regions
o Pressure and Structural Support
• Mesho Establish and then Refine
• Von Mises
• Displacement
Contact Regions
Pressure and Supports
Mesh
Von Mises
Displacement
Engineering Requirements
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Time to Clean
• Pilot study: select 30 participants, provide cleaning instructions,
time the process
• Hypothesis test (95% confidence) on the average time to clean
product
o H0: µ >= 5 minutes
o HA: µ < 5 minutes
• Adjustments in sample size (i.e. additional observations) may be
necessary depending on the variance in the observed results
• If the cleaning time is over the target value of 5 minutes, test for
marginal success of 10 minutes
Category
Score Customer Requirement Function Metric Units Marginal
Target
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Engineering Requirements
Number of Tools Required for Cleaning
• Count of tools required
• Nylon sponge or brush is best material to clean stainless
steel mesh
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Weight
Component Quantity Weight/assembly (lbs)
Bucket 2 3.60
Lid 1 .38
5 micron mesh 1 .35
Total 4.33
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Start-up Time
• Pilot study: collect 30 observations of start up time
• Hypothesis test (95% confidence) on the average start up
time
o H0: µ >= 10 seconds
o HA: µ < 10 seconds
• Adjustments in sample size (i.e. additional observations)
may be necessary depending on the variance in the
observed results
• If the cleaning time is over the target value of 10 seconds,
test for marginal success of 30 seconds
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
No Power Source Needed
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Labor Cost Estimations
• Machining Bucketo Cut out bottom of bucket: ~5 minutes
o Drilling holes (with template): ~ 5 minutes
• Cutting Mesh: ~ 1 minute
• Hot air welding: ~ 5 minutes
• Total time: 16 minutes
• Assuming a $15 / hr wage, total cost is $4
Total Cost of Components
Component Quantity Cost/assembly
Bucket 2 $5.94
Lid 1 $1.47
5 micron mesh 1 $6.32
Brush 1 $2.19
Labor Cost n/a $4.00
Total $19.92
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Mean Time to Failure
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Operating Costs
• All components will last longer than the required 2 years.
• Operating costs will be $0/year
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Turbidity
• Turbidity is caused by particles suspended or dissolved in
water that scatter light making the water appear cloudy or
murky
• Particulate matter such as clay, silt, and fine organic and
inorganic matter contribute to a high turbidity value
• Turbidity measurements are often made using optical
equipment in the field or lab
• Sediment often tops the list of substances or pollutants
causing turbidityhttp://www.pca.state.mn.us/index.php/view-document.html?gid=7854
Percentage Decrease in Turbidity
• Pilot study: collect 30 observations of turbidityo Collect before/after, compute % difference
• Hypothesis test (95% confidence) on the average % difference
o H0: µ >= .75
o HA: µ > .75
• Adjustments in sample size (i.e. additional observations) may be
necessary depending on the variance in the observed results
• If turbidity does not meet target, test at 50% for marginal
success
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Percentage Decrease in Total Suspended Solids• Pilot study: collect 30 observations of TSS
o Collect before/after, compute % difference
• Hypothesis test (95% confidence) on the average % difference
o H0: µ >= .75
o HA: µ > .75
• Adjustments in sample size (i.e. additional observations) may be
necessary depending on the variance in the observed results
• If turbidity does not meet target, test at 50% for marginal
success
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Taste of Water
• Recruit at least 100 RIT students
• Have each drink tap water that has not been treated with
the filter and water that has been treated by the filter
(blind)
• Ask each student if the water tastes better, worse, or about
the same
• Target: 75% respond with better or about the same
• Marginal: 50% respond with better or about the same
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Hazardous Releases
Engineering RequirementsCategor
yScore Customer Requirement Function Metric Units Margina
lTarget
Ease of Use 3 Easy to clean / rechargeEasy to prepare for use Time to clean minutes 10 5
Ease of Use 3 Easy to clean / recharge Easy to prepare for use
Number of tools required for cleaning by the end user
- 2 1
Ease of Use 3 Lightweight for transportMinimize weight of filter Weight in lbs lbs 10 5
Ease of Use 3 Has a minimal start-up period. Minimize start-up
Time elapsed between beginning of pour and first water that enters the bucket
seconds 30 10
Ease of Use 3Operates using only energy available naturally (gravity, human power, etc.)
Doesn't need power source
Binary (Yes/No) - - No
Economics 3 Filter is inexpensive Minimize cost of filter Total cost to produce US $ 25 20
Economics 3Usable by a family of 5, for 2-5 years w/out full replacement
Maximize durability of filter Mean Time To Failure
# of uses 730 3650
Economics 9
Requires no consumables for operation, except for very cheap & locally available materials (salt, soap, sand, etc.)
Minimize cost to maintain Annual cost to operate US $ 2 0
Functionality 9 Decreases turbidity
Turbidity is decreased Percentage Decrease % >50% >75%
Functionality
9 Decreases total suspended solids
Total suspended solids decreased
Percentage Decrease % >50% >75%
Functionality
3 Does not negatively affect the taste of the water
No negative taste of water
Percent of people who say water tastes the same or better
% >50% >75%
Safety 3 No hazardous releasesDoesn't produce hazardous release, no chemicals added
Binary (Yes/No) - - No
Functionality 3 Use Scenarios
Provides enough water for family of 5, daily Flowrate lpm 0.0394 0.6309
Mock Up Flow Testing
• Water was collected and used at different times from the
Genesee River to drive flow in a replica gravitational, 5-
gallon filter
• In an effort to replicate the flow of river water through the
particle filter, a mock up was made to see how effective the
mesh is
• The created mockup uses a mesh diameter of
approximately 2.5 in with 18 fl ounces of water put in the
filter
• The max pressure scenario here is about that of 2.5 gallon
over an 8.5 in diameter mesh
Mock Up Flow Testing
Mock Up Flow Testing
Low Turbidity Flow Calculations
oz/minfor
D=2.5infor D=8.5in
4.50 0.13 1.597.50 0.22 2.658.76 0.26 3.10
Flow Rate (L/min)
Some leakage between underside of mesh and jar
No leakage at all
Max pressure scenario in testing is only represntative of about 2.5 gallons over 8.5 inch
diameter mesh.
Notes:
Mock Up Flow Testing
High Turbidity Flow Testing
• In a very high turbidity scenario, the water put into the
system had a turbidity value of 210 NTU, about 7 times the
worst water turbidity used in the low turbidity flow testing.
• The flow rate in this scenario was 0.61 ounces per minute,
which extrapolates to 0.22 L/min, which still meets our
marginal flow rate target.
• The final turbidity was reduced by about 85 percent, in
this scenario, which meets our target requirement.
Flowrate
• Pilot study: collect 30 observations of the flow of 5 gallons of
water through the filtero Collect time elapsed to filter all 5 gallons, compute flow rate in lpm
• Hypothesis test (95% confidence) on the flow rate
o H0: µ >= .6309 lpm
o HA: µ > .6309 lpm
• Adjustments in sample size (i.e. additional observations) may be
necessary depending on the variance in the observed results
• If turbidity does not meet target, test at .0394 lpm for marginal
success
Project Management
Risk Assessment
ID Risk Item Importance Action to Minimize Risk Owner Date OpenedDate Closed (or expected)
1 Cleaning is difficult 9 Supply cleaning instruction, minimize number of parts, error-proof up/down instructions. Tom 9/17/13 2/14/14
2 Costs more than $25/unit 9 Cost is < $20. Kelly 9/17/13 11/28/133 Stress concentration 6 Spread load out around edge of filter Perry 9/17/13 11/21/134 Load Bearing Capacity 6 Calculate necessary force rating Perry 9/17/13 11/21/13
5 Flow rate is too slow 6Increase surface area of filter, find more porous materials, define minimum flow rate to test against (use scenario) Test Plan Perry 10/1/13 2/25/14
6 User not detecting tear in filter4
Instruct user to inspect both sides of the filter and closely examine the filtered water. Dan 10/1/13 2/17/14
7 Corrosion 3 Stainless steel is not going to corrode. Karina 9/17/13 10/16/138 Weight is too much 3 At under 5lbs, weight is not a risk item. Kelly 9/17/13 10/21/13
9Incorrect usage, sandwich inserted upside-down 3 Use visuals whenever possible, minimize text, poka-yoke Dan 10/3/13 12/5/13
10 Stability issues with bucket 2Design proper attachments, make sure surface is level prior to use, worse case - will the bucket withstand that? Prototype will be tested. Dan 9/17/13 3/3/14
11Filter introduces bad taste to water
2 Design is made of non-corrosive materials, test plan will determine taste results. Perry 10/24/13 3/7/14
12 Leakage 1 Hot-Air Welding significantly reduces the likelihood of leakage occuring Perry 9/17/13 11/19/13
Plan for MSD II
Next Steps
Immediate Actions from DDR
• Address by Tuesday, 12/10/13Review & Finalize Prototype
BOM
• Already completed, pending DDR feedback 12/10/13
Complete & Submit Purchase Orders for
Prototype
• By or before Wednesday, 12/11/13
Continue Experiments & Testing
• Through the start of break
Begin Statistical Analysis of Experimental & Test Data
Best Case Scenario
• To have all the components for a prototype by January 28th. (Start of
next semester)
• Have prototype built by by Friday, 2/14/13. (End of Week 3)
We feel this timeframe is feasible, due to the highly available components that make
up our Bill of Materials. In addition, our experiences from testing and
experimentation show that the machining and assembly is not very time consuming.
• By having a completed prototype by this date, we have plenty of time to
experiment with it and get real usage information to compare to our
Engineering Metrics and Specifications.
Senior Design Process & Lessons Learned
Possible Improvements
• Accessing SMEs sooner would have been helpful
• Clearer expectations at times would have helped
• More planned workshop time for groups during class in the beginning
Positives
• Guides gave plenty of feedback, both good and bad
• Overall structure is well-organized
Follow-On Suggestion
• Start working on mock ups sooner and order parts as soon as possible
• Encourage groups to contact industry professionals
Action ItemsItems Owner Due Date
Post DDR Feedback Action Items Kelly Stover 12/10/13
Finalize Prototype Bill of Materials Thomas Heberle 12/10/13
Complete Purchase Orders Kelly Stover 12/12/13
Statistical Analysis of Collected Data Daniel Anderson, Kelly Stover Continuous
Continuing Turbidity & Total Suspended Solids Testing Perry Hosmer Continuous
Continuing Mesh Durability and Cleaning Testing Karina Roundtree Continuous
Build Prototype Thomas Heberle 2/14/13
Update assembly drawings Thomas Heberle 12/12/13
Define “clean” Kelly Stover, Karina Roundtree 12/15/13
Work with Kate to better define B9 assembly operation Daniel Anderson 1/27/14
FMECA on assembly Daniel Anderson 1/27/14
Life analysis of entire assembly Karina Roundtree 2/11/14
Life analysis of nylon brush Karina Roundtree 2/11/14
Include temp of hot air weld on the assembly procedure Daniel Anderson 12/12/13
Include cleaning instructions in assembly procedure Daniel Anderson 12/12/13
Add probability of water circumventing mesh to FMEA Daniel Anderson 12/12/13
Add an engineering requirement for shipping cost Kelly Stover 12/12/13
Talk to Liz from P14418 for cheaper buckets and lids Kelly Stover 12/18/13Cost/Benefit of using screwcap vs snap fit bucket lid (durability wise) Karina Roundtree 3/1/14
Create Risk Curve Daniel Anderson, Kelly Stover 1/27/14
Questions