Engineering Design 100 Project 1

7/30/2019 Engineering Design 100 Project 1

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Engineering Design 100

Project 1

Claire Nowak

Sean Busko

Joel Croce

Changju Park

February 26, 2013

Design Team 1

Abstract:

The objective of this project was to design a more sustainable automated toothbrush. We were

first given a sample toothbrush to look at and analyze; we took into consideration everything

from the packaging to the size of the toothbrush head. We then assessed customer needs and

came up with a revised problem statement according to the customer needs. Next came the

research to find out more about the product we would be creating. We looked up various patents

and designs for products similar to the one we would be making. We used the information for the

competitors products to benchmark and assess what we liked and didnt like in the other

designs. Next we completely took apart out sample toothbrush and assessed the parts. After that,

we had to develop concepts for our product based on the customer needs. At this point in the

process, we decided to go with a rechargeable design as opposed to a battery-operated one. We

also made other decisions about the design through our analysis of the concepts we came up

with. To complete the project, we just had to make drawings of our design and explain in detail

how all the components came together in the finished product. This report outlines all the steps

we took in creating our finished product.


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1.0 Introduction1.1 Initial Problem Statement

We feel that todays electric toothbrushes could be more sustainable and environmentallyfriendly. Our task is to make a new electric toothbrush that is green and user friendly, while still

being a reasonable price. We are going to specifically focus on the power source to make the

toothbrush greener and assess customer needs to decide the final design for the product.

2.0 Customer Needs

2.1 Weighing Customer Needs

It is important to create a focus group to find out what specific needs customers are looking for.It is even more important to weigh these needs to determine what functions should appear in

your final design. We interviewed 20 people about what they were looking for in an electric

toothbrush and used their answers as the customer needs we were going to investigate.

Table 1. Initial Customer Needs List Obtained from Interviews

PortableLightweight

Comfortable to holdSafeAdjustableCompactCustomizableLow noiseEasy to operateCost of maintenanceBattery LifeStrengthGentle

Rechargeable BatteryEffective at CleaningDurableCost Effective


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Table 2. Hierarchal Customer Needs List Obtained from Interviews

1. Portable1.1 Lightweight1.2 Comfortable to hold

1.3 Adjustable Head1.4 Compact2. User friendly

2.1 Customizable2.2 Safe2.3 Easy to Operate2.4 Low noise

3. Durable3.1 Cost of maintenance3.2 Battery Life3.3 Strength

4. Functions4.1 Gentle4.2 Rechargeable4.3 Effective at cleaning

5. Cost Effective

Figure 1. AHP Pairwise Comparison Chart to Determine Weighting for Main Objective

Categories

Portable UserFriendly

Durable Functions CostEffective

Weighted

Portable 1 1/3 1/5 1/7 1/9 .03

Cost Effective 3 1 1/4 1/5 1/7 .079

Durable 5 4 1 1/3 1/5 .18

User Friendly 7 5 3 1 1/3 .28

Functions 9 7 5 3 1 .43


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Figure 2. AHP Pairwise Comparison Chart to Determine Weighting of Portable Sub-

Objectives

Lightweight Comfortableto Hold

Adjustable

HeadCompact Weighted

Lightweight 1 1/3 1/5 1/7 .052

Comfortable

to Hold3 1 1/3 1/6 .138

Adjustable

Head5 3 1 1/3 .287

Compact 7 6 3 1 .52

Figure 3. AHP Pairwise Comparison Chart to Determine Weighting of User Friendly

Sub-Objectives

Customizable Quiet Safe Easy to

Operate

Weighted

Customizable 1 1/3 1/5 1/7 .052

Quiet 3 1 1/4 1/5 .138

Safe 5 4 1 1/3 .317

Easy to

Operate

7 5 3 1 .49


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Figure 4. AHP Pairwise Comparison Chart to Determine Weighting of Durable Sub-

Objectives

Cost of

Maintenance

Battery

Life

Strength Weighted

Cost of

Maintenance

1 1/3 1/7 .08

Battery Life 3 1 1/5 .225

Strength 7 5 1 .695

Figure 5. AHP Pairwise Comparison Chart to Determine Weighting of Functions Sub-

Objectives

Gentle Rechargeable Effective at

Cleaning

Weighted

Gentle 1 1/5 1/7 .062

Rechargeable 5 1 1/6 .2868

Effective at

Cleaning

7 6 1 .65


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Table 3. Weighted Hierarchal Customer Needs List Obtained from Interviews

1. Portable (.03)1.1 Lightweight (.052)1.2 Comfortable to hold (.138)1.3 Adjustable (.287)1.4 Comfortable to hold (.52)

2. User friendly (.29)2.1 Customizable (.052)2.2 Safe (.138)2.3 Easy to Operate (.317)2.4 Low noise (.49)

3. Durable (.18)3.1 Cost of maintenance (.08)3.2 Battery Life (.225)3.3 Strength (.695)

4. Functions (.43)4.1 Gentle (.062)4.2 Rechargeable (.2868)4.3 Effective at cleaning (.65)

5. Cost Effective (.079)

3.0 Revised Problem Statement

Our original task was to create a more sustainable and user friendly toothbrush. We are goingto specifically focus on making a toothbrush that is rechargeable and does not require batteries.This will reduce waste and eliminate the need to spend money on batteries. We are also going tofocus on making a toothbrush that cleans well and is made out of durable material.

4.0 External Search


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4.1 Literature Review

4.2 Patent Search

Function Art

Kinetic Plate

Moveable

Head Sections

PoweredToothbrush Bristle

Pattern

Capacitive

on/off Switch

Motor Driven

Rotary

Rechargeable Battery US7140058

Toothbrush Head US7117555 USD477715

Toothbrush Body US5453644

Operating Mechanism US2124145

4.3 Benchmarking

Table 5. Benchmarking of Four Products

Feature Oral-B Advanced

Power 400 TX

Colgate 360 Sonic Oral-B Professional

Care 1000

Sonic Spin Brush

Packaging 3 3 4 3

Aesthetics 3 5 4 4

Ease to clean 4 4 4 4Convenience of on/offswitch

5 5 5 5

Effectiveness atcleaning teeth

4 2 5 4

Rechargeable 0 0 5 5

Gentle 3 3 5 4

Cost 0 4 3 4

Durability 4 2 5 3

Lightweight 4 5 3 3

4.4 Product Dissection


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4.4.1 Product Measurement

Location Noise Level

Brush Head 4 inches away 69.8 db

Brush head 3 inches away 70.2 dbBrush head 2 inches away 71.5 db

Brush head 1 inch away 72.1 db

DC motor 4 inches away 67.2 db




Approximate duration of daily brushing 4 minutes

Average noise during brushing 69.6 db

Part Number Material/ Function Weight

1 Bottom cover (covers batteries) 0.012 lb

2 Detachable Head (bristles and plastic with metal spring) 0.012 lb

3 Body (plastic with metal shaft) 0.158 lb

4 Battery (powers brush) 0.054 lb

5 Plastic (covers brush head) 0.006 lb

Total Voltage of Battery 1 and 2: 3.07V (connected in series)Mean Current Under Load: 0.259APower (under load) = 3.0V x 0.295A = 0.855 watts

-# of hours available per singlebattery under load conditions: 6.78 hours-Estimated duration for each brushing: 1/30 hours-# of days before battery replacement: 203 days

4.4.2 Dissection

Bill Of Materials

Bill of Materials


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Par

t #

Part

Name

QT

Y

SOP

Effec

t

Function Mas

s (lb)

Materia

l

Manuf.

Process

Dimension

s

Cost Time to

complete

Part

Dissectio

n

1 Spring 1 Yes Suspend

s Motor

.001 Metal Spring

Mold

0.6cm by

0.5cm

$0.1

5

2 minutes

2 Motor 1 No Moves

Metal

Rod

.074 Metal Metal

Casting

Assembl

y

4.5cm by

1.6cm

$0.0

7

2 minutes

3 Metal

Clip

1 Yes Makes

clip

connect

to

bottom

.002 Metal Casting 4.1cm by

1.5cm

$0.0

5

2 minutes

4 Black

andRed

Wires

2 No Connects

batteriesto motor

.001 Copper

plastic

Wiring 6cm long $0.0

8

2 minutes

5 Rotato

r

1 No Connects

to

motor;

moves

back and

forth

.002 Metal Casting

Assembl

y

0.5 long $0.0

5

2 minutes

6 Power

Button

1 No Push and

makes

brushwork

.002 Plastic Injection

assembly

0.3 long $0.0

2

2 minutes

7 Plastic

Case

1 Yes Covers

motor


Molding

2.5cm by

1.5cm

$0.0

4

3 minutes

8 Metal

Shaft

1 No Moves

brush

.010 Metal Casting 7.5cm $0.5

0

3 minutes

9 Brush 1 No Brushes

teeth


Molding

0.9cm $0.4

0

0 minutes

10 Body 1 Yes Covers

motor


Molding

14cm by

2.5cm

$0.3

0

1 minutes


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Component Subassembly Chart

Electric Toothbrush

Bottom BodyToothbrush Head

Brush Shaft HeadinternalsCasingBatteries

Motor MetalSh

aft

Rotator Base

Clip

Wires Spring Rod Cap


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Morphological Chart

Concept Generation Table

Power Source Brush Handle Switch Type Brush spin Other

1 AA Batteries Rubber One button Full Rotation Plays music

2 Rechargeable Rubber Slide Side to side Interchangeable head

3 AA Batteries Rubber Two buttons Up, down side

to side

Timer

4 Rechargeable Rubber One button Full Rotation Rechargeable Base

Power Source Brush

Handle

Switch Type Brushing

Direction

Other Functions


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Our new and improved design,

Our design is different from most because of its unique brush head. The brush head is not only

removable but the bristles themselves are unique. They are in a ring shape and they will rotate

360 degrees clockwise. The reason for them being in a ring shape is to make brushing around

the edges of your teeth easier and more effective.

The concept is powered by a rechargeable battery, which can be charged in an hour and will

work for half of the charging time or 30 minutes. This makes it easier to travel with your

toothbrush not worrying about bringing the charging station with you. We chose a rechargeable

battery because itseasy to use and doesnt take up as much space as batteries do in the

toothbrush. Batteries are hard to dispose of and not very good for the environment, which is

another reason why we chose rechargeable.

The toothbrush also has a very unique aspect to the grip and power module. The toothbrush will

start to work just by touching the grip. We decided that a push button can be difficult foryounger kids or older adults because sometimes they may be difficult to push. We eliminated

this by having the touch grip because all you have to do is hold onto the rubber comfortable grip

and the brush begins to rotate.

Review

There are many kinds of toothbrushes out there to choose from, including manual, battery-

powered, and rechargeable automated toothbrushes. Battery-powered toothbrushes are different

from electric toothbrushes, aside from being rechargeable. Battery-powered toothbrushes usuallyonly vibrate the bristles of the head to clean. Electric toothbrushes can oscillate, vibrate, or rotate

depending on which one you get. Although battery-powered toothbrushes are less expensive,

electric toothbrushes have to be replaced far less and you do not have to buy batteries for them.

Most battery- operated toothbrushes also dont give you the option to switch out heads. (1) Our

sample toothbrush was the Oral-B Advance Power 400TX. The actual retail price of our sample

toothbrush was $204.99. When looking through the website, we noticed that the rechargeable

toothbrushes were dramatically less expensive than the battery-powered toothbrushes. This

further encouraged us to design a more affordable rechargeable electric toothbrush. (2) We

researched the Colgate 360 Sonic toothbrush, which is automated. The average price of this

toothbrush is around $30. The toothbrush has a vibrating head and uses one AAA alkaline

battery and is not rechargeable and does not come with a warranty. The head cannot be replaced.

(3) The Oral-B Professional Care 1000 toothbrush is rechargeable and comes with a charging

stand. It has a two minute timer and pressure sensor to prevent gum damage, indicates when the

head needs to be changed, and has a two-year warranty. Its price is around $70. (4) The Sonic

Spinbrush (rechargeable) is a rechargeable toothbrush that features a two minute timer and


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Engineering Design 100 Project 1

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