PENNSTATE

Fork and Spoon Holder

Final Report

May 4, 2015

Jennifer Kohler

Brian Leap

JD Maguire

Grace Warkulwiz

Evan Witmer

No - Intellectual Property Rights Agreement

No - Non-Disclosure Agreement

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Executive Summary The objective of this project was to design a device that would allow the client, who has a

muscular/neurological disability, to eat independently. The client suffers from Charcot-Marie-Tooth

(CMT) disease, which affects the peripheral nerves and leads to muscular weakening, making eating

and holding utensils difficult. The device the client used in the past was created by previous Penn

State students. It was permanently attached to the client’s wrist brace and was used during three

meals a day, offering a more dynamic eating experience. The device accepted utensils of specific

sizes and locked them into place. The past design functioned like a ball-point pen; with each click of

the device’s bottom button on a surface, the utensil rotated 45 degrees in one direction.

Current products on the market do not meet the client’s needs as a user with CMT disease. The

devices do not accept a variety of eating utensil sizes, and they do not angle or rotate the utensil to

ease the transition from plate to mouth. Additionally, some of the products that would actually meet

the client’s primary needs are too bulky and technologically advanced; the client wishes to feel as

normal as possible while eating with his device. The past Penn State-designed product is preferred

over the competition because it permits utensils to rotate, allowing the client to feed himself.

Although it is preferred, the past design causes user dissatisfaction due to difficulties that arise when

exchanging the utensils. In addition, the client has complications with pushing the rotation button as

well as concerns with durability.

The three concerns of the client were addressed through the design of a new eating assistive

device. After talking to the client and watching him use the device, the team decided the primary

goal: improve upon the past rotational mechanism to increase the device’s durability and ease of use.

To accomplish this, a new rotation mechanism was implemented to freely rotate a utensil 360

degrees in both directions to any desired angle without using debilitating hardware. The team

implemented the new rotation mechanism through two different prototypes. The first included a

mechanism by which a key block on the terminal device fit into a key hole on a separate piece

attached to the client’s opposite wrist. Once the key block was inserted into the hole, the client could

rotate the utensil using his shoulder and upper arm strength. However, the client did not prefer this

design because the turning motion required of his shoulder was too strenuous. The second prototype

excluded the key hole piece and instead included an attachable wheel on the bottom of the key

block. When the wheel was rolled on any surface, including the client’s hand, the utensil rotated

freely. This roller device was preferred by the client and was customized to fit his needs. The team

made adjustments to the device’s dimensions to make the rolling mechanism more comfortable and

convenient. The final design shortened the device’s overall length and moved the wheel up closer to

the end of the client’s wrist brace.

To successfully develop a working prototype, the team was given a budget of $1000.00 that was

allocated strategically to successfully accommodate the client’s needs. The prototypes were 3D

printed in ABS plastic at the Learning Factory. The team finished the project with about a tenth of

their budget remaining. The total cost to manufacture one roller device, based on the final design,

was ~ $40.00. The team actively engaged with the client and sponsor to plan deadlines and set goals

for prototypes. The initial prototype of the terminal device was brought to the client and sponsor for

testing and feedback by the March 1, 2015, deadline. Since early March, the team has made three

additional trips back to the client and sponsor with modified versions of the two prototypes as they

either failed or progressed. The final design will be delivered to our sponsor and client on May 4,

2015, for permanent attachment to the client’s wrist brace for immediate use.

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Table of Contents 1.0 Introduction ................................................................................................................................... 5

1.1 Initial Problem Statement ......................................................................................................... 5

1.2 Objectives ................................................................................................................................... 5

2.0 Customer Needs Assessment ........................................................................................................ 6

2.1 Gathering Customer Input ....................................................................................................... 6

2.2 Weighting of Customer Needs .................................................................................................. 6

3.0 External Search ............................................................................................................................. 8

3.1 Patents......................................................................................................................................... 8

3.2 Existing Products ....................................................................................................................... 9

4.0 Engineering Specifications ......................................................................................................... 10

4.1 Establishing Target Specifications ......................................................................................... 10

4.2 Relating Specifications to Customer Needs ........................................................................... 12

5.0 Concept Generation and Selection ............................................................................................ 12

5.1 Problem Clarification .............................................................................................................. 12

5.2 Concept Generation ................................................................................................................. 14

5.3 Concept Selection ..................................................................................................................... 17

6.0 System Level Design ................................................................................................................... 18

7.0 Special Topics .............................................................................................................................. 21

7.1 Preliminary Economic Analyses - Budget and Vendor Purchase Information ................. 21

7.2 Project Management ............................................................................................................... 21

7.3 Risk Plan and Safety................................................................................................................ 21

7.4 Ethics Statement ...................................................................................................................... 23

7.5 Environmental Statement ....................................................................................................... 23

7.6 Regulatory Considerations ..................................................................................................... 23

7.7 Communication and Coordination with Sponsor ................................................................. 23

8.0 Detailed Design ............................................................................................................................ 24

8.1 Manufacturing Process Plan................................................................................................... 25

8.2 Analysis ..................................................................................................................................... 34

8.3 Material and Material Selection Process ............................................................................... 35

8.4 Component and Component Selection Process..................................................................... 36

8.4.1 Component and Component Selection Process for Key Hole and Key Block Device ...... 36

8.4.2 Component and Component Selection Process for Rolling Device .................................. 36

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8.5 CAD Drawings ......................................................................................................................... 37

8.6 Test Procedure ......................................................................................................................... 38

8.7 Economic Analyses - Budget and Vendor Purchase Information ....................................... 38

9.0 Final Discussion ........................................................................................................................... 39

9.1 Construction Process ............................................................................................................... 40

9.2 Test Results and Discussion .................................................................................................... 44

10.0 Conclusions and Recommendations ........................................................................................ 47

11.0 Self-Assessment (Design Criteria Satisfaction) ...................................................................... 48

11.1 Customer Needs Assessment................................................................................................. 48

11.2 Global and Societal Needs Assessment ................................................................................ 48

References .......................................................................................................................................... 49

Appendices ......................................................................................................................................... 50

Appendix A: Patent Descriptions ................................................................................................. 50

Appendix B: Detailed Existing Product Summary ..................................................................... 51

Appendix C: Budget Table ........................................................................................................... 54

Appendix D: Bill of Materials....................................................................................................... 54

Appendix E: Gantt Chart ............................................................................................................. 55

Appendix F: Resumes .................................................................................................................... 56

Appendix G: Deliverables Agreement ......................................................................................... 61

Appendix H: Design Changes since the SOW Report ................................................................ 62

Engineering Specifications ......................................................................................................... 62

Concept Generation and Selection .............................................................................................. 62

System Level Design .................................................................................................................. 65

Appendix I: Design Changes since the DSR ................................................................................ 67

Engineering Specifications ......................................................................................................... 67

Concept Generation and Selection .............................................................................................. 67

System Level Design .................................................................................................................. 68

Appendix J: Past CAD Drawings ................................................................................................. 70

Appendix K: Final CAD Drawings .............................................................................................. 74

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1.0 Introduction Charcot-Marie-Tooth disease (CMT) is a genetically inherited disorder that affects the peripheral

nerves and is one of the most common neurological disorders in the United States, affecting

approximately one in every 2,500 people. People affected by CMT have mutations in the genes that

produce proteins involved in myelin sheaths and peripheral nerve function. The nerves affected by

these mutations are unable to communicate electrical signals and slowly degenerate as the patient

ages. Because both the motor and sensory nerves are affected, the patient may have difficulty

walking. As the disease progresses, the hand and wrist muscles weaken causing the patient to have

difficulty carrying out fine motor skills [1].

There is currently no cure for CMT, so doctors focus their efforts on rehabilitation and therapy,

which help the patients with managing physical challenges. Occupational therapists work with CMT

patients to help them maintain fine finger movements, while physical therapists develop

strengthening exercises to help maintain mobility [2]. Braces and orthopedic devices can be used to

prevent injury and to help manage the disability, but no device currently exists for CMT patients that

allows them to eat happily and normally on their own. The current products on the market lack the

ability to hold a variety of silverware sizes, while also rotating the silverware to various angles to

make feeding oneself easiest. A device needs to be created that can hold and stabilize a utensil so

that these patients can regain some independence and confidence.

1.1 Initial Problem Statement While therapy helps patients with CMT to maintain some mobility, very little has been done to

help patients maintain independence with everyday tasks, such as eating. The goal of this project is

to design a device that will allow a person lacking finger strength to eat independently. The team

will be provided past prototypes and designs and will be given the freedom to completely redesign a

device or modify a past design. The device must be able to hold a fork or spoon securely while the

patient eats, and the utensils must be removable and switched easily. The client desires to eat in

restaurants using the provided utensils; therefore, the device must be able to accommodate a broad

range of shapes and sizes. The utensil also needs to be able to rotate within the device, to mimic the

natural rotation of the hand while eating.

The sponsor for this project is the Central Pennsylvania Spinal Cord Injury (SCI) Support Group,

which consists of a team of doctors and therapists from the Penn State Milton S. Hershey Medical

Center. The Central Pennsylvania SCI Support Group helps individuals cope emotionally and

physically with their disease diagnosis, specializing on those affected by spinal cord injuries [3].

1.2 Objectives Through discussions with the client and the sponsor, many problems with the past PSU device

were conveyed. However, due to time and budget restrictions, some of these issues will not be

addressed in the proposed design, and only the primary issues will be addressed as stated above. The

team’s design will be different than past PSU prototypes in terms of internal hardware but will not

be significantly different in size, shape, or overall function. The device currently utilized by the

client is wearing out due to frequent use and mechanical imperfections. The mechanical wear is

mainly due to the rotating mechanism that is implemented in the device. The client also becomes

easily frustrated with the fact that he needs to rotate the utensil to a neutral position to remove it. The

new design will utilize a different rotation mechanism to increase the durability and to alleviate this

frustration. In addition, the client expressed that a device that could fit a more versatile range of

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utensil widths would be beneficial. The team will decrease the column thickness in order to increase

the possible utensil width, keeping in mind that this might limit the structural integrity.

While examining the past PSU designs after meeting with the client, the team decided that the

utensil could fit more securely into the fork/spoon holder. To better meet this need, slight

modifications will be made to the internal pin. In addition to a more efficient rotation mechanism, a

more natural eating experience could result if the device were able to angle up and down vertically.

However, this would require some form of lever and clamp system and is therefore out of the scope

of the team’s work.

2.0 Customer Needs Assessment

2.1 Gathering Customer Input The needs of our client were acquired in a few different ways. Initially, the team discussed the

needs of the proposed device over a video call with our client, Marty. We also met with Dr. Hills and

Marty in person to discuss previous design prototypes and deliverables. To further develop the list of

customer needs, the client was observed using previous designs, while the team took note of

particular aspects that could be improved with the previous device. Through question and answer

sessions with the sponsor and client, the team was able to determine all of the needs that must be met

for this project. The client expressed a handful of requests, some being outside the scope of the

project. After some discussion, the primary focus of the device is to be functional and durable.

2.2 Weighting of Customer Needs Analytical Hierarchy Process (AHP) is a method used for multiple criteria decision-making.

Using an AHP matrix has numerous benefits. For one, an AHP derives priorities among criteria and

alternatives while keeping the judgment consistent. By using pair-wise comparisons, the team can

decompose the decision-making problem into a hierarchy. Once a hierarchy is established, the pair-

wise comparisons between each criterion can be made. By developing a scale of importance, values

can be assigned to a given relationship. For this AHP comparison, the team will use the following

scale:

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Table 1: AHP weighting scale

Scale Degree of Preference

1 Equal importance

3 Moderate importance of one factor over another

5 Strong or essential importance

7 Very strong importance

9 Extreme importance

Table 1 shows the possible ratings of comparisons between two factors. The scale includes

integers from 1 (equal value) to 9 (extreme difference) where the higher number represents that the

chosen factor is considered more important in greater degree than the other factor being compared.

The upper triangular matrix uses the following rules:

1. If the judgment value is on the left side of 1, actual judgment value is used.

2. If the judgment value is on the right side of 1, the reciprocal value is used.

First, a hierarchy of needs was developed to get a general idea of what categories were most

important in our design. Next, pair-wise comparisons were made according to the scale above to

“weight” each criterion. To compute the entire AHP matrix, different degrees of preference were

given to each pair-wise comparison. We came up with eight different categories that applied to our

project.

The matrix below shows that “Ease of use” was our top priority in the design of the device. This

characteristic was equally important to the next two important categories: “Functional” and

“Durable”. The client stressed the importance of these three categories due to his condition. We

decided “Ease of use” was nine times more important than “Adaptable” and “Cost” because the

device will be used exclusively by one person, daily. Hence, “Cost” was our lowest rated criteria, as

we thought the price was irrelevant for a device that will be used habitually. The “Function” and

“Durable” criterion were weighted equally, and were much more important than being reproducible.

We determined that if we made the device more durable, the reproducibility of the product is

unnecessary. The “Safety” of the device received a median weight, as we established it to be of some

importance, but not a priority.

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Table 2: AHP Pairwise Comparison Chart to Determine Weighting for

Main Objective Categories

3.0 External Search

3.1 Patents Patents pertaining to the past Penn State fork and spoon holder are summarized in Table 2. Patent

US 3288115 A describes a ballpoint pen mechanism and the concept of protracting and retracting the

ink cartridge within it. US 5630276 A describes a self-leveling eating utensil made for people with

disabilities so that they can feed themselves. US 659341 A is a patent that focuses on a utensil’s

ability to self-stabilize using a clamp. Patent US 4389777 A pertains to a device that secures an

eating utensil to an instrument base. Additionally, patents that are relevant to the team’s new device

are charted in Table 3. A key and chuck mechanism is described in patent US 2012147 A. Each

patent focuses on a function and is categorized as affecting the mechanical, aesthetic, or technical

design for the two different devices. Additional information on all of the patents can be found in

Appendix A.

Table 3: Art-Function Matrix of Patents for Past Fork and Spoon Device

Function Mechanical Design Aesthetic Design Technical Design

Pen mechanism:

US 3288115 A

X X

Internal rotating

hardware:

US 5630276 A

X

X

Utensil clamp:

US 659341 A

X

Attachment:

US 4389777 A

X

Functional Durable Adaptable Cost Weight Reproducible Safe Ease of use Total Weight

Functional 1.00 1.00 5.00 7.00 3.00 7.00 1.00 1.00 26.00 0.19

Durable 1.00 1.00 5.00 7.00 3.00 7.00 1.00 1.00 26.00 0.19

Adaptable 0.20 0.20 1.00 3.00 0.33 1.00 0.33 0.11 6.18 0.05

Cost 0.14 0.14 0.33 1.00 0.14 0.33 0.20 0.11 2.41 0.02

Weight 0.33 0.33 3.00 7.00 1.00 3.00 1.00 0.33 16.00 0.12

Reproducabile 0.14 0.14 1.00 3.00 0.33 1.00 0.33 0.11 6.06 0.05

Safe 1.00 1.00 3.00 5.00 1.00 3.00 1.00 0.33 15.33 0.11

Ease of use 1.00 1.00 9.00 9.00 3.00 9.00 3.00 1.00 36.00 0.27

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Table 4: Art-Function Matrix of Patents for New Fork and Spoon Device

Function Mechanical Design Aesthetic Design Technical Design

Internal rotating

hardware:

US 5630276 A

X

X

Utensil clamp:

US 659341 A

X

Key hole and key

block mechanism:

US 2012147 A

X

X

3.2 Existing Products There are a number of assistive eating devices currently available, each with its own specific

design to make eating easier for the individual end users. As shown in Figure 1, the products vary

from device cuffs that attach to the hand or arm and accept silverware (A) to adaptive utensils with

larger, softer grips that are sometimes angled or curved (B). Robotic devices also exist (C). These

three groups of products are designed in mind for a specific customer. For example, cuffs that wrap

around the palm or wrist are designed for individuals with some arm strength but little to no gripping

ability in their hands or fingers. Adaptive utensils are designed for individuals with conditions like

moderate arthritis. Robotic devices exist for individuals with limited muscle strength in their arms,

hands, and fingers. On average, attachment cuffs can cost anywhere from $5 to $30 [4-8]. Adaptive

utensils are in the $10 range [9], and robotic assistive devices are a much more expensive option,

costing hundreds to thousands of dollars [10]. An extensive summary of all research products can be

found in Appendix B.

Figure 1: A summary of the varied assistive eating devices currently on the market. Slip-on

utensil cuffs (A) and adaptive utensils (B) are some of the most common. High-tech solutions

such as robotic devices (C) are also available [5,9,10].

Although a wide range of assistive eating devices exists on the market today, similarities can be

drawn amongst the various designs. One of the most common features is an opening into which the

utensil can be inserted and held into place. This concept is seen in all of the attachment cuff products

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and even in some adaptive silverware devices. This opening is usually a flap made out of leather,

nylon, or other materials. Most of the attachment cuff devices have utensil openings that fix the fork

or spoon parallel to the palm [4-7]. The robotic devices require purchasing customized silverware to

use with the product [10]. Specific silverware is also sometimes needed with the attachment cuffs or

adaptive utensil devices [6, 9, 10]. All of the adaptive silverware, as well as some of the attachment

cuffs, are designed to be robust and round in order to help patients maintain a firm grip during meals

[4, 7, 9].

Assistive eating devices include a broad range of products for individuals of varying disabilities.

However, there are several disadvantages specific to the Fork & Spoon semester project with the

current designs. As a result of these disadvantages, the devices do not meet the needs of individuals

with CMT disease who wish to continue to be independent eaters both at and away from home. The

first disadvantage is a lack of universal acceptance for utensil types. The existing products on the

market are not universal and usually fit only a specific type of fork or spoon. In fact, grip solutions’

“Hand Grip” is the only product that includes several differently sized slits [7]. Because of this

problem, the client with CMT disease is limited to the type of silverware he can use with these

devices, making it difficult when he goes out for meals at restaurants or friends’ houses. The second

major flaw with the current devices on the market is that most of the utensils are held in a fixed

position without the ability to rotate to additional positions once inserted. An individual utilizes

multiple rotations and anglings of the wrist while eating, and these devices do not allow for that. The

cuff products fix utensils parallel to the palm. The product “Right Angle Eating Utensil Holder” is

one of the only stationary devices that allow users to eat at an angle normal to the palm, rather than

parallel [8]. Robotic products, such as “iArm,” are large and robust [10]. Additionally, these devices

cause quite a scene for individuals. These individuals, as well as the team’s client, want to gain a

better sense of independence while staying inconspicuous.

4.0 Engineering Specifications

4.1 Establishing Target Specifications

The team redesigned the original model of the device to satisfy the new needs of the client. The

client expressed three major needs: an increase in durability, an improved rotating mechanism, and a

wider insert to fit a variety of forks and spoon sizes.

Table 4 below displays the target dimensions of the device components. The dimensions of the

key hole and key block are the most important because they need to be big enough for the client to

make the connection between the key hole and key block. These changes correspond to improving

the rotating mechanism. Another important factor is the width of the pin. The width of the pin, which

holds the utensils inside the device, must be big enough to accommodate different sizes of forks and

spoons.

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Table 5: Initial Target Specifications and Values

Metric Importance Target Value Units

Cylinder Length 3 5.5 cm

Cylinder Outer Diameter 1 2.8 cm

Cylinder Inner Diameter 1 2.6 cm

Top Cap Length 1 1.8 cm

Top Cap Outer Diameter 1 3.5 cm

Top Cap Inner Diameter 1 3.2 cm

Bottom Cap Length 1 1.8 cm

Bottom Cap Outer Diameter 1 3.5 cm

Bottom Cap Inner Diameter 1 3.5 cm

Key Block Length 5 1.5 cm

Key Block Width 5 1.5 cm

Key Block Thickness 9 2 cm

Key Hole Length 5 3 cm

Key Hole Width 5 3 cm

Key Hole Thickness 9 3 cm

Pin Length 3 8 cm

Pin Width 7 3 cm

Area of Fabric 5 50 cm2

Spring Length 1 2.5 cm

Spring Diameter 1 2.5 cm

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4.2 Relating Specifications to Customer Needs The team developed the Needs Metric Matrix found in Table 5. The Needs Metric Matrix

displays the client’s needs and the specification metrics that are affected by these needs. The matrix

is a tool that helped the team determine how each part of the device will be tested based off of the

specific need that it corresponds to.

Table 6: Needs Metrics Matrix

Met

ric

Cy

lin

der

Len

gth

Cy

lin

der

Ou

ter

Dia

met

er

Cy

lin

der

In

ner

Dia

met

er

To

p C

ap L

eng

th

To

p C

ap O

ute

r D

iam

eter

To

p C

ap I

nn

er D

iam

eter

Bo

tto

m C

ap L

eng

th

Bo

tto

m C

ap O

ute

r D

iam

eter

Bo

tto

m C

ap I

nn

er D

iam

eter

Key

Blo

ck L

eng

th

Key

Blo

ck W

idth

Key

Blo

ck T

hic

kn

ess

Key

Ho

le L

eng

th

Key

Ho

le W

idth

Key

Ho

le T

hic

kn

ess

Pin

Len

gth

Pin

Wid

th

Are

a o

f F

abri

c

Sp

rin

g L

eng

th

Sp

rin

g D

iam

eter

Need

Utensil stability

while eating X X X X X X X X X X X

Utensil stability

while locked X X X X X X

Internal hard-ware

can withstand

long-term use

X X X X X X X X X X X X X X X X X

Light weight X X X X X X X X X X X

Angle of fork and

spoon can be

changed

X X X X X X X X X X

Widening insert to

accept varies of

forks and spoon

X X X X X X X X X

5.0 Concept Generation and Selection

5.1 Problem Clarification

The “black-box” model and sub-function diagram of the fork and spoon holder device are shown

in Figures 2 and 3, respectively. The “black-box” model displays the inputs entering into the fork

and spoon holder device to achieve the output of the client being able to eat independently. The fork

and spoon holder device is being modified to accommodate various fork and spoon sizes. A spandex

material is used to fasten the silverware to the pin, adding overall security. The remaining parts of

the device are made out of acrylonitrile butadiene styrene (ABS) plastic, adding overall durability.

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Figure 2: The “black-box” model graphically depicts the five inputs of the fork and spoon

holder device, outputting the overall ability to eat independently.

The sub-function diagram displays the individual functions that occur inside the device while the

client is using it. For the client to successfully eat independently, the device must be able to change

the angles of the fork and spoon easily. To ensure that the angle of the fork and spoon can change

easily, a rotating key hole and block mechanism now exists. This mechanism is ideal because the

client has limited strength to produce a force strong enough to turn the fork or spoon independently.

All the various inputs for the fork and spoon holder are necessary to achieve the required output.

Figure 3: The sub-function diagram shows how various inputs affect the individual functions

of the device and how they work together to allow the client to eat independently with the

product.

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5.2 Concept Generation After interviewing the sponsor and client extensively, the design team has decided to focus on

tackling three primary functions. These include increasing versatility of the device to fit a broader

range of utensils, increasing durability for a longer-lasting device, and increasing security and hold

of the utensil in the terminal device. For each function, two concepts were brainstormed as possible

solutions as shown in the morphological chart in Table 6. Each of these concepts is outlined below.

Table 7: Morphological Chart for Sub-Function Concept Generation

Function Concept A Concept B

Fit a broader range of

utensils

Increase all dimensions of the

terminal device

Decrease the thickness of the

cylinder

Increase Durability Use a different material Eliminate spring/clicking action for

rotation mechanism

Create a more secure

hold for utensils

Modify slightly the shape of the

clamp to increase contact points

Add an elastic-like fabric that can

better hold utensil onto clamp

For the function of versatility, two possible solutions were brainstormed. In order to accept a

wider utensil, the team initially suggested increasing all dimensions of the terminal device. Although

this concept would expand the opening to accept larger silverware, the client expressed that he is

satisfied with the overall shape and size of the device. Therefore, this idea was eliminated. The

second solution for increased versatility was to decrease the thickness of the cylinder slightly. This

change would increase the width of the pin to hold wider utensils, while keeping the overall shape

and size of the design the same. The team decided attempt to make this change; however, a possible

limitation is negatively affecting the structural integrity of the device. A basic figure for this concept

is shown in Figure 4.

Figure 4: Decreasing the thickness of the outer cylindrical casing will be explored to

improve the overall versatility of the device.

Through the investigation of old internal hardware of a recent device that failed, the team

concluded that the materials were subject to wear due to high usage of the device by the client daily.

The metal spring wore down the plastic casing and gears. In order to alleviate some of these

degradations, the team suggested using a tougher material for the device. A tougher material will

help the product last longer with time; however, hard plastics used in 3D printing are costly and

would greatly affect the team’s budget. Another concept to address the function of durability was to

include reducing the stress that the spring exerts on the terminal device. The team proposed changing

the rotation mechanism in order to (1) make it easier for the client to change the utensil angle and (2)

increase durability. The proposed rotation mechanism is a key hole and key block set, where the

client would place the device end into a hole and rotate his shoulder/arm to rotate the utensil. The

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key hole would need to be attached to a firm surface - either the table, client’s other hand, or the

client’s thigh. This new mechanism would decrease the action of the spring and also address the

issue of having to click the button 180 degrees if the desired angle was passed. However, the client

may not prefer using his shoulder strength to rotate the device and could have difficulty inserting the

key block into the key hole. As a result, the team will test every single prototype with the client as

soon as they are 3D printed to obtain all feedback.

Figure 5: Increased durability will be addressed in the new design by altering the rotation

mechanism of the device using a key hole and key block concept.

Modifications could also be made to the current device to improve the security of the utensil and

decrease any wiggling while eating. The past device has a pin whose shape is displayed in Figure 6.

With that design, there is only one primary contact point when the utensil is locked into place. By

altering the shape of the pin, as shown in Figure 7, the team would increase the number of contact

points and therefore increase the stability of the utensil overall. The flaw with altering the pin in this

way is that the plastic material provides no stretch or give when utensils of larger sizes are inserted

into the opening. Therefore, the team might need to investigate using a more rubber based material,

which can be 3D printed.

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Figure 6: The current shape of the pin exhibits one primary contact point with the utensil,

decreasing silverware security during use.

Figure 7: The proposed new shape of the pin will increase contact points with the utensil,

offering better overall silverware security during meal time.

An additional concept for increasing utensil stability is adding an elastic/spandex material to a

one sided pin to better hold the fork/spoon onto a clamp. This concept is depicted in Figure 8. The

material would need to conform to varying shapes and sizes and be tight enough to prevent wiggling

while eating. The fabric would line the top of the pin with an additional piece tightly fastened on top.

The two fabric surfaces would provide friction when the utensil is inserted. A spandex material

could be used for this application because it can be fastened tightly but also has the ability to stretch

to accommodate various sizes. However, the team will be challenged by this concept when attaching

the material so that it exhibits a specific tightness that accepts and holds firmly in place very thin and

flat utensils as well as large and round ones.

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Figure 8: A spandex fabric sleeve on top of the pin has the potential to add utensil stability

due to friction, stretch, and tightness.

5.3 Concept Selection Through discussions and brainstorming sessions, the least favored ideas from Section 5.2 were

eliminated, and the remaining concepts were added to the Pugh Scoring Matrix (Table 7). Concept A

for the function of versatility is not favored because the client expressed that the current size of the

device is satisfactory. Concept B will be attempted in the final design but may limit the structural

integrity of the device; therefore, it is not a primary concern.

The concept of a new rotation mechanism (key hole and key block) had a higher rating than the

current reference. The shape of the pin that had the highest rating was the angled pin, with the fabric

sleeve pin coming in a close second. The angled pin will increase the number of contact points with

the utensil, increasing the stability of the fork/spoon. While the fabric sleeve will also increase the

security of the utensil, it will increase the cost of the device.

18

Table 8: Pugh Scoring Matrix

Concepts

Overall Design Shape of Pin

Key Hole and

Block

Spring and Gear

(Reference Device)

Angled Pin to

Increase

Contact

Fabric Sleeve

Current Shape of

Pin

(Reference)

Selection

Criteria Weight Rating

Wgtd.

Score Rating

Wgtd.

Score Rating

Wgtd.

Score Rating

Wgtd.

Score Rating

Wgtd.

Score

Functional 0.194 4 0.776 3 0.582 5 0.970 4 0.776 3 0.582

Durable 0.194 5 0.970 3 0.582 3 0.582 3 0.582 3 0.582

Adaptable 0.046 3 0.138 3 0.138 3 0.138 3 0.138 3 0.138

Cost 0.018 3 0.054 3 0.054 3 0.054 2 0.036 3 0.054

Weight 0.119 2 0.239 3 0.358 3 0.358 4 0.477 3 0.358

Reproducible 0.045 3 0.135 3 0.135 3 0.135 3 0.135 3 0.135

Safe 0.114 3 0.343 3 0.343 3 0.343 3 0.343 3 0.343

Ease of use 0.269 5 1.343 3 0.806 3 0.806 3 0.806 3 0.806

Total

Score 3.999 2.999 3.387 3.294 2.999

Rank 1 2 1 2 3

Continu

e Yes No

Yes, primary

design Yes, alt. design No

Relative Performance Rating

Much worse than

reference 1

Worse than reference 2

Same as reference 3

Better than reference 4

Much better than reference 5

6.0 System Level Design The overall design will require the use of a “key hole and block” system to rotate the piece

holding the silverware. The key block, which is attached to the bottom gear (A), protrudes through

the bottom opening of the outer shell (B). When the utensil needs to be rotated, the block is placed

into the key hole (C) and pivoted, engaging the gears and rotating the pin (D) that holds the utensil.

The key hole can be attached to the opposite hand or leg for stabilization by use of Velcro straps or

elastic bands. The spring (E) is compressed over the utensil holder pin when the cap (F) is tightened

onto the outer shell.

19

Figure 10: Assembled View of

“Keyhole and Block Device”

Within the concept above, there are two inserts that can be used to hold the utensil. The first

insert, shown as (D) in Figures 9 and 10, resembles that of a clothespin. The utensil slides between

the two jaws, and when the spring collapses, the jaws clamp onto the utensil. The jaws are tapered

outward, so that when the jaws tighten, they apply even pressure linearly along the utensil handle. A

close-up of this design shows the tapered jaws in Figure 11 below.

The second insert, shown below in Figure 12, uses fabric to enclose the utensil inside the device.

The fabric, which is elastic in nature, can adapt to a wide variety of silverware sizes and provides

360 degrees of pressure to keep the utensil steady within the device. The fabric insert and clothespin-

style insert can be interchangeable within the device and will not require any special tools or skills to

swap out. Figure 13 shows the specification drawings, and the assembly of the proposed device.

Figure 9: Exploded View of “Keyhole and

Block Device”

20

Figure 13: Specification Drawing of Clothespin Insert Assembly in Inches

Figure 11: Clothespin Style Insert Figure 12: Fabric Style Insert

21

7.0 Special Topics

7.1 Preliminary Economic Analyses - Budget and Vendor Purchase Information A budget has been developed to properly distribute the funds needed to successfully complete the

fork and spoon holder design. The initial budget, found in Appendix C, is split into four categories:

bill of materials, equipment cost, travel, and contingency. A portion of our budget (20%) will be

allotted for any contingencies that may occur. As for travel, the use of a team member’s personal car

will minimize the team’s expenses as well as being reimbursed for gas receipts instead of mileage.

The majority of the team’s expenses will come from 3D printing different prototypes for the client.

Following the initial budget is the team’s estimated bill of materials, found in Appendix D. The bill

of materials contains the estimated prices of each material used to design the fork and spoon holder.

7.2 Project Management The project Gantt chart can be seen in Appendix E. The chart is broken down into four main

categories, the “Final Report”, the “Working Prototype”, the “Weekly Progress Reports” and

“Other”. Under the “Final Report” category, there are subsections including the “Statement of Work

(SOW) and the “Design Specification Report (DSR)”. This Gantt chart was created to keep the team

on track with major deadline and to make it easy to track progress along the way.

With the team’s technical and management skills, the customer needs will be fulfilled by the end

of the semester. A resume of each team member can be found in Appendix F. The deadlines set forth

in the Deliverables Agreement can be found in Appendix G. The major work that needs to be

completed by the end of the semester includes three major reports: (the SOW, the DSR, and the final

report. In addition, the team must present the details of the SOW to the class, assemble and test an

initial prototype, construct a final working prototype, give a final presentation, and attend the

College of Engineering design showcase.

7.3 Risk Plan and Safety The device the team is designing does not cause any safety concerns for the user. Because the

device will contact both solid and liquid food at varying temperatures, the device will be made of a

plastic that will not be altered by the temperature of the food. The team’s primary focus is to design

a device that has minimal risks.

The team identified seven risks that were ranked high, moderate, or low as displayed in Table 9.

The highest risks that the team identified were scheduling delays and the product not functioning

properly for the client. Scheduling delays are high risk because on any given day, something can

occur that can cause the team to deviate from schedule and risk missing a deadline. The way the

team will handle that is by strictly following the Gantt chart and constantly staying in

communication with one another. In addition, the device not functioning properly for the client is a

high risk because it is difficult to mimic the client’s disability while testing the prototype among the

team. The way the team is handling this is by ensuring that the client tests the device as often as

possible as the team makes the appropriate modifications to the device.

The team identified not meeting client’s needs, a change in the client’s needs, a delay in

manufacturing and assembling the device, and the device having minimal longevity as moderate

22

risk. These are moderate minimal risks because the team has several strategies set in place to

minimize these risks.

As for low risk, the team only identified the device not being reproducible for this level. The

reason for this risk being low is the device is made a minimal parts and thorough documentation of

the design will ensure easy reproduction. At the end of the semester, the team must make sure the

design is saved and given to the sponsor as well as every team member future reference.

Table 9. Risk Management Plan

Risk Level Actions to Minimize Fall Back Strategy

Not meeting client’s

needs Moderate Testing prototypes

early and often

Listening to the

client’s exact needs

Focus on one main need

rather than multiple needs at a

time

Ensuring that team can print

old device in case new device

does not meet needs

Change in client’s

needs Moderate Constantly be in

contact with sponsor

and client

Making a device that

is adaptable to the

client’s needs

Make small modifications to

device to meet needs

Adjust budget for

modification and rush

assembly

Scheduling delays High Utilize Gantt chart

Working ahead of

scheduled due dates

Keep in constant contact with

team members

Include extra time before

deadlines

Delay in

manufacturing and

assembling

Moderate Provide 3D sketches

for printing two days

in advance to

Learning Factory

Make sure all parts

are correctly

measured and fit

properly

Use secondary 3D printer in

Hammond Building

Use past parts to successfully

assemble a working device

Device does not

function properly

for client

High Allowing client to

test prototypes in

advance to ensure

functionality

Keeping in mind

client’s disability as

prototypes are being

assembled

Make small modifications to

past design so client at least

has a working device

Rush to clients house to make

small repairs to device so that

it functions properly

Device has minimal

longevity Moderate Assuring that the

device is made from

Producing multiple

prototypes so if one breaks,

23

a durable material

Testing material to

ensure that it can

withstand forces

client puts on it

client will have extras

Have a back-up material if

current material used is not

durable enough

Device is not

reproducible Low Proper

documentation and

saving of all files for

future use

Having 3D prints

readily available

Ensure sponsor’s personal 3D

printer has all files relating to

device’s design

Give design files to Dr. Hills

to have future groups

reproduce device

7.4 Ethics Statement The team will conduct our research in a manner that is consistent with accepted scientific

methods, maintaining the highest standards of honesty and integrity in all professional endeavors.

All sources of inspiration, information, and assistance with the project design will be recognized and

stated. The safety of the design for the user will be guaranteed and will always be the top priority of

the team. All progress, ideas, and concerns regarding the design will be shared immediately between

team members, the user, and the team’s sponsor. Current patents will not be infringed upon. The

team’s intentions and concerns will never veer from improving the life and daily habits of the

disabled user.

7.5 Environmental Statement The team does not expect major environmental concerns in the manufacture of the design or its

materials. The team will abide by environmental regulations and standards in the creation of its

design. Environmental impact will be strongly considered with each of the team’s decisions. The

processes selected for the manufacture of the design will produce the minimum environmental

impact achievable. There will be an emphasis on using recycled and biodegradable materials

whenever the option is available.

7.6 Regulatory Considerations FDA review will not be necessary as the device is categorized as a low-risk medical device since

it is not inserted into the user’s body. Low-risk medical devices do not require premarket review

when they are for the same use as an already legally-marketed device. Splints and gloves for helping

users with difficulty using their fingers already legally exist on the market place. Of the four major

forms of certification (UL, CSA, ETL or CE), the only certification that would apply to the design

would be UL. Due to the low safety risk of the design, a UL certification does not seem necessary.

The device will most likely be assumed safe by any user familiar with splints and other assistive

living devices.

7.7 Communication and Coordination with Sponsor The team communicates with the primary contact, Dr. Hills, and the client via different methods

dependent on the purpose of the interaction. Email is used in order to quickly send the sponsor

documentation such as progress reports, design ideas, and other important documentation involved

in the creation of the team’s design. Email is also used in order to set up the site visits to the sponsor.

The site visits occur whenever new prototypes need to be tested by the user or when supplies and

24

models from past designs need to be collected and analyzed. When the team wants to have an

interactive discussion with the client, a Skype session is set up.

8.0 Detailed Design

Section 8.0.1 Modifications to Statement of Work Sections

8.0.1.1. Introduction – no change

8.0.1.2. Customer Needs – no change

8.0.1.3. External Search An additional patent has been found that is relevant to the roller wheel of the rolling device’s

design. Information on this patent can be found in Appendix A.

8.0.1.4. Engineering Specifications

At the request of the client, several changes have been made to the engineering specifications of

the initial prototype designs. The importance of the cylinder length was changed from a 3 to a 6 due

to new concerns from Marty. The client’s thumb was dragging through his food on a daily basis, and

as a result, the team revised the length of the cylinder to attempt to fix this issue. The original

cylinder’s length value of 5.5 cm was changed to 9.2 cm. In order to accommodate for the added 2

cm to the cylinder length value, 2 cm was added to the original key block length as well. The target

value of 1.5 cm was changed to 3.5 cm. The original key hole width target value was changed from 3

cm to 1.5 cm to match the key block width target value of 1.5 cm.

Several metrics and values have been removed from the target specifications because some

aspects of the original prototype are longer relevant or present in the team’s new prototypes. The

spring length and spring diameter target values were removed because the team decided to not

incorporate a spring into the design. The area of fabric target value was removed because the team is

no longer pursuing the fabric pin insert. Revisions to the target specifications can be seen in Table

H.1 in Appendix H.

8.0.1.5. Concept Generation and Selection

The primary design concept has been modified to include an additional prototype design with a

rolling rotation mechanism. In addition, the key hole piece of the key block and hole prototype has

been redesigned to more comfortably fit the client’s wrist during use. Details of these modifications

are described in Appendix H along with Figures H.1-H.3.

8.0.1.6. System Level Design

A revised exploded view of the system is shown in Appendix H in Figures H.4-H.6. The changes

include a modified pin insert, an extended outer shell, a different key hole attachment, and an

additional roller prototype.

8.0.1.7. Special Topics The Gantt Chart has been updated to reflect current timeline of deliverables as seen in Appendix

E. The Bill of Materials in Appendix D has been updated to include material purchased since the

SOW Report. These materials include fabric, Velcro, suction cups, Dycem, and 3D printed

prototypes.

25

8.1 Manufacturing Process Plan If the device was to be manufactured by a non-Fork & Spoon team member, the team will provide

the party with the proper STL files. The necessary files were finalized by the team in SolidWorks

and converted to STL files in March 2015. The team will share the files via email with those

manufacturing the device. The manufacturing process currently takes place at the Penn State

Learning Factory. All one needs to do is provide the Learning Factory employees with the Fork &

Spoon STL files obtained from the team. The employees take care of uploading the files to the

printer, programming the printer with various settings, and removing support material. As a result,

the team cannot contribute any details regarding the printing process since they rely on an outside

source for printing.

The following materials are needed to successfully manufacture the key hole and key block

device: a total of five STL files (one for each piece of the device), Dimension 1200es 3D printer,

ABS plastic (to be printed), ½” thick blue open-cell T-stick foam*, superglue, and 1” wide non-

industrial Velcro. The following steps are summarized in Table 10:

1. Upload the five STL files at the Penn State Learning factory to the Dimension 1200es 3D

printer with the help of an employee.

2. Print all five pieces on the Dimension 1200es 3D printer using ABS plastic (~ nine hours

total). The pieces include the outer casing, key block piece, pin, cap, and radial key hole

piece.

3. Prepare the foam piece: cut a piece of ½” thick blue open-cell T-foam 2 inches (48 mm) long

and 0.8 inches (21 mm) wide. Leave the adhesive backing on the foam. Seal the front edge of

the foam completely with a layer of superglue. Let it dry until it hardens. See reference image

below.

4. Prepare the pin piece: cut a piece of ½” thick blue open-cell T-foam 2 inches (48 mm) long

and 0.8 inches (21 mm) wide. Secure the piece of foam with superglue to one of the pin

sides. Be sure to superglue the piece foam side down. Keep the adhesive backing on the foam

and unsecured. See reference imagine below.

26

5. Hold the outer casing with the large opening facing upwards and the small opening facing

downwards. Drop the key block piece to the bottom with the gears facing up. Pull on the

block to ensure that the piece is as far down as it can go inside of the casing. See reference

image below.

27

6. Drop the pin insert with the gears facing down into the outer casing so that it falls on top of

the key block piece. See reference image below.

7. Locate the circular knobs on the outside of the outer casing piece. Place the cap onto the top

of the outer casing, making sure that the knob enters the opening of the cap’s “L” slit. Once

the knob has made it to the back of the “L” slit opening, turn the cap piece so that the knob

slides along the horizontal length of the “L” slit. One will know when the knobs are securely

in the slits because the cap will not rotate further. Although the material is durable, take

caution with this step and be gentle so that the cap piece does not break. See reference

images below.

28

8. Cut a piece of the 1” wide Velcro 8 inches (203 mm) long. Insert it through the openings of

the radial key hole piece with the Velcro side facing upwards.

* The color of open-cell T-foam in medical applications corresponds to different resistances. This is

universal. For example, blue open-cell T-foam is more resistive than pink, yet less resistive than

black.

The following materials are needed to successfully manufacture the rolling device: a total of five

STL files (one for each piece of the device), Dimension 1200es 3D printer, ABS plastic (to be

printed), ½” thick blue open-cell T-stick foam, superglue, and Dycem. The following steps are

summarized in Table 11:

1. Upload the five STL files at the Penn State Learning factory to the Dimension 1200es 3D

printer with the help of an employee.

2. Print all five pieces on the Dimension 1200es 3D printer using ABS plastic (~ nine hours

total). The pieces include the outer casing, key block piece, pin, cap, and roller wheel.

3. Prepare the foam piece: cut a piece of ½” thick blue open-cell T-foam 2 inches (48 mm) long

and 0.8 inches (21 mm) wide. Leave the adhesive backing on the foam. Seal the front edge of

the foam completely with a layer of superglue. Let it dry until it hardens. See reference image

below.

29

4. Prepare the pin piece: cut a piece of ½” thick blue open-cell T-foam 2 inches (48 mm) long

and 0.8 inches (21 mm) wide. Secure the piece of foam with superglue to one of the pin

sides. Be sure to superglue the piece foam side down. Keep the adhesive backing on the foam

and unsecured. See reference imagine below.

5. Prepare the roller wheel: cut a piece of Dycem 1.4 inches (35 mm) long and 0.3 inches (6.5

mm) wide. Superglue it to the outer rim of the roller wheel.

6. Hold the outer casing with the large opening facing upwards and the small opening facing

downwards. Drop the key block piece to the bottom with the gears facing up. Pull on the

block to ensure that the piece is as far down as it can go inside of the casing. See reference

30

image below.

7. Drop the pin insert with the gears facing down into the outer casing so that it falls on top of

the key block piece. See reference image below.

31

8. Locate the circular knobs on the outside of the outer casing piece. Place the cap onto the top

of the outer casing, making sure that the knob enters the opening of the cap’s “L” slit. Once

the knob has made it to the back of the “L” slit opening, turn the cap piece so that the knob

slides along the horizontal length of the “L” slit. One will know when the knobs are securely

in the slits because the cap will not rotate further. Although the material is durable, take

caution with this step and be gentle so that the cap piece does not break. See reference

images below.

9. Put a layer of superglue in the circular indent on the roller piece. Snap the roller wheel onto

the key block by lining up the circular block with the circular indent on the roller piece and

pushing down.

Table 10. Manufacturing Process Plan for Key Hole and Key Block Device

ASSEMBLY NAME MATERIAL

TYPE

RAW

STOCK

SIZE

OPERATIONS

Outer casing ABS plastic N/A Load STL file and print piece on

Dimension 3D printer.

Check for the circular knobs – are there

four raised printed circles?

Key block ABS plastic N/A Load STL file and print piece on

Dimension 3D printer.

32

Check gears - are there 3D rectangles all

the way around the top of the piece? Are

any of the gears missing or not fully

printed?

Key hole ABS plastic

N/A

Load STL file and print piece on

Dimension 3D printer.

Velcro 12’ x ¾”

roll

Cut an 8 inch piece - insert through

straps with Velcro side facing up.

Pin ABS plastic

N/A

Load STL file and print piece on

Dimension 3D printer.

Check gears - are there 3D rectangles all

the way around the bottom of the piece?

Are any of the gears missing or not fully

printed?

½” thick blue

open-cell T-stick

foam

Superglue

1/2" x 6" x

72" sheet

Cut a piece of foam 2 inches long and

0.8 inches wide. Secure the pieces with

superglue to either side of the pin.

Cap ABS plastic N/A Load STL file and print piece on

Dimension 3D printer.

ASSEMBLY NAME MATERIAL

TYPE

RAW

STOCK

SIZE

OPERATIONS

Terminal device

(everything excluding

the key hole piece)

Obtain outer casing - large opening

facing upwards.

Drop the key block into casing with

gears facing up.

Drop the pin into casing with gears

facing down.

Lock cap onto casing using slits and

knobs.

33

Table 11. Manufacturing Process Plan for Rolling Device

ASSEMBLY

NAME

MATERIAL

TYPE

RAW

STOCK

SIZE

OPERATIONS

Outer casing ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

Check that locking knobs on the outside of

the case were printed successfully.

Key block ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

Check gears to make sure that they were

printed successfully.

Roller wheel ABC plastic

N/A

Load STL file and print piece on Dimension

3D printer.

Dycem

Superglue

16’ x 1-⅛”

strip

Cut a strip 1.4 inches long and 0.3 inches

wide. Superglue to the outer edge of the

wheel.

Pin ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

Check gears to make sure that they were

printed successfully.

½” thick blue open-

cell T-stick foam

Superglue

1

1/2" x 6" x

72" sheet

Cut a piece of foam 2 inches long and 0.8

inches wide. Secure the pieces with

superglue to either side of the pin.

Cap ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

ASSEMBLY

NAME

MATERIAL

TYPE

RAW

STOCK

SIZE

OPERATIONS

34

Terminal

device

Superglue Obtain outer casing - large opening facing

upwards.

Drop the key block into casing with gears

facing up.

Drop the pin into casing with gears facing

down.

Lock the cap onto casing using slits and

knobs.

Fasten the roller wheel to the bottom of the

key block piece with superglue.

8.2 Analysis The team did not find it necessary to do any Finite Element Analysis to prove our design. The

initial prototype designs were modeled after past working Penn State prototypes that the client is

currently using. Because the client has had successful experiences with the past Penn State

prototypes that were printed using ABS plastic, the material was assumed to be strong enough to

withstand any stresses or forces exerted on it during use.

Because the team was unsure as to how the new assembly and rotation mechanism would work,

the group was careful not to waste part of the budget by printing a full prototype in ABS plastic.

Therefore, experimentation of the preliminary printing of the main parts was carried out using the

MakerBot printer in the Learning Factory. The MakerBot printer was free to use; however, the

quality was very poor. The MakerBot only printed one piece before the machine broke. The team

analyzed what was printed and consulted the Learning Factory employees. During the consultation,

the employees notified the team that the MakerBot breaks down almost every time a user tries to

print on it. As a result, the team came up with a plan B.

The team decided to print some of the pieces from the initial prototype using a more reliable

printing machine: the Dimension 1200es 3D printer. Only the pin insert, the key block, and the key

hole pieces were printed to save material and money because they were the only new or modified

pieces. The group obtained past prototype pieces from the sponsor and used them in combination

with the newly printed pieces to test the assembly method and rotation mechanism. Through this

experiment, the team found that some of the pieces needed to be redimensioned slightly in order to

fit together properly and carry out the desired functionality. Initially, the team spent some time in the

Learning Factory filing the plastic and eventually redimensioned the SolidWorks drawings to

finalize the design dimensions. These new dimensions are reflected in the Engineering Specification

section.

The rotation of the two prototypes was analyzed for functionality and ease of rotation. The

rotation of the key hole and key block device resulted from friction between the gearing pieces and

the outer casing. Therefore, the force needed to rotate the utensil could not be directly measured.

Through initial testing, the team was able to rotate the utensil with minimal shoulder force.

Subsequent testing was carried out with the client. A greater force was required when using the key

hole piece that was attached to the table compared to the key hole piece attached to the client’s

opposing hand. Movement with both hands afforded by attachment to the opposing hand allowed for

easier rotation; however, the team felt that the client exerted too much energy and effort in order to

35

turn the utensil a small angle. The team simulated Marty’s motions while using the device and

determined that the utensil would rotate at most 45 degrees with each shoulder movement. The client

would then need to reposition the device to continue rotating the utensil.

During the team’s meeting with the client and during testing of the key hole and key block

prototype, a new idea for a different rotation mechanism was created. A rotation mechanism that

could be implemented by the client by simply rolling the block piece along the table edge or a pant

leg would require less effort from the client. After the prototype was designed and 3D printed, the

team analyzed its ease of rotation by measuring the distance it needed to be rolled along the table

edge in order to rotate 180 degrees which measured approximately 2.7 inches (68.6 mm). Because

the rotation of the utensil is solely dependent on the rotation of the gear piece, the relationship was

linear, and minimal rolling was necessary to rotate the utensil.

8.3 Material and Material Selection Process To successfully design a prototype tailored to the team’s client, three major needs must be

satisfied – versatility, security, and durability. Material selection for the prototype was used to

satisfy the need for durability. To ensure that the team’s prototype was durable, a relatively strong

material was essential. Because the team intended to 3D print the prototype, a specific type of

thermoplastic polymer had to be chosen. Due to the constraints of 3D printing in the Penn State

Learning Factory, the team had to choose from three different materials – acrylonitrile butadiene

styrene (ABS), polylactic acid (PLA), and high impact polystyrene (HIPS). After thoroughly

researching these materials, the team decided to print the prototypes with ABS. ABS is the strongest

and cheapest of the three, exhibiting high temperature resistance. HIPS is dissolvable in most

liquids, which is unacceptable for a device that comes in close contact with liquids during meals.

PLA stores moisture from the air, diminishing the strength of the material over time.

All three prototypes constructed to date have been printed with ABS. There are only two

components of the prototypes that include other materials adhered to them. The first is the pin that

holds the utensil in place. Because the client stressed that he liked the foam inserts in the model he

uses now, it was obvious to insert foam into the team’s newly designed pin. Marty’s occupational

therapist placed closed-cell foam in the model he uses now; therefore, the team reached out to her to

obtain similar materials for the new prototypes. The team experimented with both open-cell and

closed-cell foam in the new pin insert. After many tests, the team decided to use the open-cell foam

because it had better memory than the closed-cell foam allowing the foam to mold better around the

utensil.

The second part of the new prototype design that has material adhered to it is the wheel

attachment at the bottom of the roller prototype. Because the wheel must be in contact with another

surface and the coefficient of friction must be high in order to rotate the wheel, the team researched

non-slip materials. A material that is commonly used by physical therapists is Dycem. Dycem is

non-slip, rubber-like plastic. The team decided to purchase Dycem and adhere it to the entire wheel,

increasing the coefficient of friction when the wheel comes in contact with a surface. With much

research and trial of materials, the team has decided that the prototypes will be constructed from

three different materials: ABS, open-cell foam, and Dycem.

36

8.4 Component and Component Selection Process 8.4.1 Component and Component Selection Process for Key Hole and Key Block Device

There are five main components for the key hole and key block device. These include the outer

casing, the key block/gear piece, the key hole, the pin, and the cap. Due to the ease of

manufacturing, availability, cost, and time, all components were designed in SolidWorks and printed

on a 3D printer.

The outer casing of the device was designed to be cylindrical, with an overall length of 3.63

inches (92.20 mm) and a diameter of 0.886 inches (22.50 mm). This shape and size were based on

those of the past Penn State device, due to previous client satisfaction with the size of device. The

outer casing in combination with the cap has an indentation that allows for easy attachment of the

device to a splint worn by the client. The cap has grooves that align with knobs on the outer casing,

and when twisted, the cap is securely fastened into place. The cap holds the pin securely in the

device.

The pin shape was also kept similar to past Penn State designs, because it has proven to hold a

utensil securely in place. The pin resembles a clothespin, in which a utensil can be inserted and

removed with ease. The team has attached one open-cell foam insert to one side of the pin in order to

cushion and hold the utensil in place. The team also experimented with Dycem, a non-stick material,

to see how well it held the utensil in place. However, the group found that the hold would be too

strong for the client to manipulate, and he would not be able to remove the utensil from the Dycem.

For this particular prototype design, a key hole and key block were designed together in order to

enable rotation of the utensil. The gear piece that previously had a button on the end (used in the past

Penn State prototype) was redesigned to have a rectangular block on the end. This block was

designed with the client in mind and is fairly large and simple in shape to ensure easy insertion into

the key hole piece. The key hole piece was designed with a semi-circle shape to comfortably fit on

the side of the client’s wrist. There is a large rectangular hole for insertion of the key block. This

wrist piece has slots for Velcro to be attached and used for attachment to the client’s wrist. Velcro

was chosen for this design because the client can successfully attach and detach the Velcro on his

splint using his mouth.

8.4.2 Component and Component Selection Process for Rolling Device There are five main components for the rolling device. These include the outer casing, the pin, the

cap, the gear piece/roller cylinder, and the wheel attachment. The pin, outer casing, and cap designs

were all chosen for the same factors described in the section 8.4.1.

This prototype was designed to have a different rotation mechanism, where the client can roll a

wheel along a table edge or pant leg to rotate the utensil. The gear piece that previously had a button

on the end (used in the past Penn State prototype) was redesigned to be a simple cylinder. An

attachable wheel with a circular cut-out can be secured onto the end of the gear piece/cylinder block.

This wheel was designed to be the same diameter as the base of the outer casing. The wheel has been

made detachable so that during the prototyping process, it can be reprinted in different sizes without

having to re-print the entire gear piece. Dycem, a readily available and low-cost material, will be

added to the wheel surfaces to increase friction between the wheel and table edge.

37

There were minimal tradeoffs created by modifying the design to a roller. By changing the key

block to a cylinder with a wheel, we decreased the contact point for rotation. The ease of wheel

rotation depends slightly on the shape and thickness of the table it will be used on. However, the

client can easily rotate the wheel on his opposite hand. Moreover, there is an additional material and

cost necessary for assembly (Dycem). This new design also requires more ABS plastic to be printed

due to elongation of the device and an added wheel piece.

8.5 CAD Drawings The assembled view of the key block device can be seen in Figure 14 below. This prototype uses

the square key and key hole to rotate the inner pin that holds the utensil. Within this prototype, the

inner pin that holds the utensil has been expanded and fitted with compressive foam to better secure

the fork or spoon. The key hole at the bottom of the picture has been designed with an arc to be

strapped to the user’s wrist.

Figure 14: Assembled view of key hole and block device

The assembled view and drawing of the wheel roller device can be seen below in Figure 15. This

prototype uses the same internal pieces as the key block device. However, there is a cylinder that

extends below the casing with a rotational wheel at the end. The wheel rotates the inner pin when

rolled along a table edge or pant leg. This wheel is covered with Dycem to increase the coefficient of

friction between the wheel and the material it comes in contact with to induce rotation.

Figure 15: Assembled view of roller device

38

All individual dimensioned component drawings are shown in Appendix J in Figures J.1-J.8.

8.6 Test Procedure All prototypes and final designs will be tested for the following characteristics: ease of utensil

rotation, ease of inserting and removing utensils, and stability of the utensil while eating. All designs

will be tested by our client Marty at his home for convenience.

Ease of rotation will assess how easy it is to use the key hole and key block or roller components.

Our client will rotate a utensil in the holder to three positions he finds essential for his daily eating

habits and judge how difficult it was to accomplish. Ease of insertion/removal will assess the

versatility of utensils capable of being used in the new design. Our client will attempt to insert then

remove three different forks with varying sized handles ranging from thin to thick. He will then

judge how difficult each fork was inserted and then removed. Stability of the utensil will test how

still and secure the utensils remain within the holder during dining. Our client will cut and eat a roll

with a fork inserted into the holder. The client will judge how steady the fork felt within the holder

while dining.

The client will rate each of these three tests on a scale of 1 to 5; 1 being much worse than his

current holder, 3 being the same, and 5 being much better. An example of the evaluation form can be

seen in Table 12.

Table 12. Sample Design Evaluation Form

Design Evaluation Sheet Design Creator: Fork & Spoon Holder Capstone Project

Tested By: Marty Kester

Prototype with Key Hole and Key Block Mechanism

Name of Test Ease of

rotation test

Ease of

insertion/removal test

Stability of the

utensil test

Rating (1-5)

Comments (Suggestions,

Improvements, etc.)

8.7 Economic Analyses - Budget and Vendor Purchase Information The budget and Bill of Materials (BOM) tables have been updated in Appendix C and D. The

team spent a majority of the budget on developing different prototypes to meet the client’s needs.

Materials such as Velcro, Dycem, foam, adhesives, fabrics, and suction cups were also purchased to

test different ways to improve the team’s prototype. After travel expenses were calculated, the team

has approximately 65% of the budget remaining. The budget contains some rough estimates for how

much money the team will spend on each category.

39

9.0 Final Discussion Section 9.0.1 Modifications to Statement of Work and DSR Sections

9.0.1.1. Introduction – no change

9.0.1.2. Customer Needs – no change

9.0.1.3. External Search – no change

9.0.1.4. Engineering Specifications

Several changes were made to the engineering specifications to achieve a final prototype as a

result of client and team discussions. Some specifications were deleted from the table, including the

key block and key hole components as they are no longer relevant to the final design. Due to

Marty’s concerns with the device sticking out too far and being too close to his hand, the team

modified the outer casing. An extension length of approximately 1.0 cm was attached to the top of

the outer casing. To address the device being too long, the outer casing was shortened to 6.4 cm.

Lastly, the team decided to simplify the device’s design by combining the two original pieces for the

pin and key block into one long pin piece with a longer mouth. Doing so effectively increased the

security of the utensil because the utensil could then be inserted farther into the device. The

importance of the pin length was changed from a 3 to a 6. The length of the pin is now much longer

due to combining the pin piece and the lower gear block piece. The entire pin length is now 14.5 cm.

Lastly, a roller wheel was added as a metric in the target specifications table. The wheel has a

diameter of 3.2 cm. All revisions to target specifications can be seen in Table I.1 in Appendix I.

9.0.1.5. Concept Generation and Selection

The general concept of a roller wheel rotation mechanism did not change since the DSR.

However, the team did design a thumb rest cap attachment piece for added comfort to the client. The

client ended up not liking the thumb rest, and the design concept was disregarded in the final device.

Details regarding the thumb rest cap can be found in Appendix I.

9.0.1.6. System Level Design

A revised exploded view and assembled view of the system is shown in Appendix I in Figures

I.3-I.4. New CAD specification drawings can be found in Appendix K, Figures K.1-K.8. The final

prototype utilizes the roller wheel rotation mechanism. It has been shortened to better satisfy the

client and a dropdown component has been added to the outer shell to drop the device away from the

palm for a more comfortable thumb position. The pin piece has been combined with the key block

gear piece to simplify the design and to elongate the pin gap. This allows the client to insert the

utensils further into the device and for better security of the utensil. In addition, the wheel

attachment hole has been modified to a square shape to minimize slipping between the cylinder

block and the wheel.

9.0.1.7. Special Topics

The Gantt Chart has been updated to reflect the complete timeline of deliverables as seen in

Appendix E. Appendix C and D contain the finalized budget and Bill of Materials (BOM). The

majority of the budget (~50%) was spent on 3D printing the team’s prototypes. It was important that

the team develop the best prototype to fit the client’s changing needs. A total of fourteen prototypes

were printed to ensure that the client was satisfied with the team’s final prototype. Of the $1000

allotted to the team, all but $88.61 was used. The budget breakdown is as followed: $65 for the

showcase poster, $192.25 for traveling to and from the team’s client/sponsor at Hershey Medical,

40

$112.30 for materials used to construct the final prototype, and $541.84 for 3D printing all of the

prototypes.

9.0.1.8 Detailed Design

The key hole and key block device was not changed or modified. As a result of the feedback from

the client, the team concluded to leave this design behind and continue further with the roller device.

The manufacturing and construction process for the final roller device can be found in Section 9.1.

9.1 Construction Process

If the device was to be constructed by a non-Fork & Spoon team member, the team will provide

the party with the proper STL files. The necessary files were finalized by the team in SolidWorks

and converted to STL files in April 2015. The team will share the files via email with those

manufacturing the device. The manufacturing process currently takes place at the Penn State

Learning Factory. All one needs to do is provide the Learning Factory employees with the Fork &

Spoon STL files obtained from the team. The employees take care of uploading the files to the

printer, programming the printer with various settings, and removing support material. As a result,

the team cannot contribute any details regarding the printing process since they rely on an outside

source for printing.

The following materials are needed to successfully manufacture and construct the finalized roller

device: a total of four STL files (one for each piece of the device), Dimension 1200es 3D printer,

ABS plastic (to be printed), ½” thick blue open-cell T-stick foam*, superglue, and Dycem. The

following steps are summarized in Table 13:

1. Upload the four STL files at the Penn State Learning factory to the Dimension 1200es 3D

printer with the help of an employee.

2. Print all five pieces on the Dimension 1200es 3D printer using ABS plastic (~ nine hours

total). The pieces include the outer casing, key block piece, pin, cap, and roller wheel.

3. Prepare the foam piece: cut a piece of ½” thick blue open-cell T-foam 2 inches (48 mm) long

and 0.8 inches (21mm) wide. Leave the adhesive backing on the foam. Seal the front edge of

the foam completely with a layer of superglue. Let it dry until it hardens. See reference

images below.

41

4. Prepare the pin piece: Slide the foam piece from Step 3 into the pin mouth until is it

completely inserted (no adhesive is needed).

5. Prepare the roller wheel: cut a piece of Dycem 1.4 inches (35 mm) long and 0.3 inches (6.5

mm) wide. Superglue it to the outer rim of the roller wheel. See reference imagine below.

6. Hold the outer casing with the large opening facing upwards and the small opening facing

downwards. Drop the pin piece to the bottom with the mouth of the pin facing up. Pull on the

cylindrical extension to ensure that the piece is as far down as it can go inside of the casing.

See reference image below.

42

7. Locate the circular knobs on the outside of the outer casing piece. Place the cap onto the top

of the outer casing, making sure that the knob enters the opening of the cap’s “L” slit. Once

the knob has made it to the back of the “L” slit opening, turn the cap piece so that the knob

slides along the horizontal length of the “L” slit. One will know when the knobs are securely

in the slits because the cap will not rotate further. Although the material is durable, take

caution with this step and be gentle so that the cap piece does not break. See reference

images below.

8. Put a layer of superglue in the circular indent on the roller piece. Snap the roller wheel onto

the key block by lining up the circular block with the circular indent on the roller piece and

pushing down. See reference image below.

43

Table 13. Manufacturing/Construction Process Plan for Final Roller Device

ASSEMBLY

NAME

MATERIAL

TYPE

RAW

STOCK

SIZE

OPERATIONS

Outer casing ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

Check that locking knobs on the outside of the

case were printed successfully.

Roller wheel ABC plastic

N/A

Load STL file and print piece on Dimension

3D printer.

Dycem

Superglue

16’ x 1-⅛”

strip

Cut a strip 1.4 inches long and 0.3 inches

wide. Superglue to the outer edge of the

wheel.

44

Pin ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

½” thick blue open

cell T-stick foam

1

1/2" x 6" x

72" sheet

Cut a piece of foam 2 inches long and 0.8

inches wide. Slide the foam piece into the pin,

keeping the white adhesive backing attached.

Cap ABS plastic N/A Load STL file and print piece on Dimension

3D printer.

Complete roller

device

Superglue Obtain outer casing - large opening facing

upwards.

Drop the pin into casing with the mouth facing

upwards.

Lock the cap onto casing using “L” slits and

knobs.

Fasten the roller wheel to the bottom of the

key block piece with superglue.

A picture of the final assembled roller device can be seen below in Figure 16:

Figure 16: Assembled roller device

* The color of open-cell T-foam in medical applications corresponds to different resistances. This is

universal. For example, blue open-cell T-foam is more resistive than pink, yet less resistive than

black.

9.2 Test Results and Discussion The team identified five possible modes of failure to test. These modes of failure include

component stress due to rotation, breakage or slipping of Dycem, decreased friction between the

wheel and block (slipping), versatility of utensils that can be inserted/removed, and foam security on

utensil. The team designed tests to analyse each of these modes of failure, and these included three

45

durability tests, a utensil versatility test, and a foam security test. Table 14 briefly describes each of

the tests and their results.

Table 14. Failure Modes and Test Results Failure mode Test Results

1. Component stress due

to rotation

Screw gun rotation test Rotated 1,805 times without failure

2. Breakage or slipping of

Dycem

Grip strength test Did not break or slip with team

member’s greatest strength

3. Friction between block

and wheel

Rotation test Minimal slipping occurred; team

changed attachment shape from a

circle to a square

4. Versatility of utensil

width

Tested widest/thickest

and thinnest forks in the

device

Thick fork is held tightly and is

more difficult to insert; thin fork is

easy to insert with minimal sliding

5. Foam security Added weight to utensil

and held upside down in

device

Foam held up to 54.1 grams, which

is more than the heaviest spoon on

the market

The first test that was conducted was a rotation test to determine how many times the device

could be rotated prior to failure due to component stress. The team attached the device to a setup

with a screw gun drilled into a wooden peg that was attached to the wheel of the device. The outer

casing of the device was held in place with duct tape. This setup can be seen below in Figure 17.

Figure 17: Screw gun setup with device for rotation testing

The screw gun was set to a continuous speed, and the team calculated the rpm by counting the

number of rotations in 15 seconds and multiplying this value by 4. The screw gun was then left on

for a set period of time, and the number of rotations was calculated by multiplying the rpm by the

time in minutes. The utensil was rotated a total number of 1,805 times before the prototype was

damaged by the speed of the drill and could no longer rotate. After these rotations, the device was

still functional. Failure occurred when the drill was set on too high of a speed. The ABS plastic of

46

the device melted the cap shut onto the outer casing. This would not happen during client use as he

would never rotate the pin at such a high speed. The team is confident that minimal wear occurs on

the device as it is rotated, and the stress put on the device by the client is considerably less than that

of the drill.

The second test was to test the durability of the Dycem on the wheel. To ensure that the Dycem

that is glued to the end of the wheel will not rip or slip off, a strength test was conducted. A member

of the team used a device to measure his grip strength. The wheel was then taken and dragged

against a table. The wheel took a lot of force before it slipped on the pin, and the Dycem did not rip

off. This confirms that the Dycem on the end of the wheel would withstand the force that the client

would exert on the Dycem.

During a second rotation test, the friction between the wheel and the cylinder block piece was

tested. The block was held steady, and the wheel was rotated by itself. After approximately 10

minutes of rotating the wheel on high speed with the screw gun, the wheel began to slip off of the

cylinder block. In order to address this potential issue, the team modified the base of the cylinder

block and changed the shape of the hole in the wheel from a circle to a square. That way, the wheel

would not slip off of the block after an extended duration of use. A picture of the modified block

attachment hole is shown below in Figure 18. In addition to the altered shape of the wheel

attachment hole, the team designed an additional wheel shape to further increase ease of rotation.

The new wheel was designed with four spokes, which allows the user to hook his or her finger in

between the spokes and rotate the device. The spoked wheel was mainly designed with

manufacturing purposes in mind (i.e. for a universal device). However, the client will receive a

spoked wheel as well as a regular wheel, and he will chose which wheel he wishes to have on his

device. The client will be provided multiple wheels with Dycem in case of failure of either the

Dycem or of the wheel slipping off.

Figure 18: Modified square wheel holes to prevent slipping

The overall versatility of the device was tested using the client’s thickest/widest fork and the

thinnest fork that the team could find. These utensils were inserted into the device, and the ease of

rotation was observed. The thick fork was more difficult to insert and remove than the thin fork but

was held tighter in the foam. The thin fork was easily inserted and removed and only had minimal

sliding within the device during use. The test also showed that thicker forks require slightly more

work to rotate the pin.

The final test was to determine how well the foam would secure the utensils in within the device.

A 24.1 gram spoon was inserted into the foam. Weights were tied to the head of spoon, and the

device was held upside down to test if the spoon would slip from the grip of the foam. The foam

47

held up to a total of 54.1 grams before the spoon fell. The heaviest spoon found on the market was

45.6 grams, so the foam should sustain a secure hold on utensils of any weight. In addition, the client

never holds the device directly vertical during use, so the added balancing force of the bottom pin

further secures the utensil during use. After testing the device for possible modes of failure, the team

is confident that the final device satisfies all client needs and will hold up after being used daily for a

long duration.

10.0 Conclusions and Recommendations The Fork and Spoon design team set out to create a device that would assist our client with CMT

disease in eating independently despite his lack of finger and wrist mobility. Assistive eating devices

on the market are not universal and only fit specific utensils. Additionally, they are held in a fixed

position without the ability to rotate as required by our client. At the start of the project, the client

used a device designed by past Penn State students. It rotated via a spring and gear mechanism,

which lead to internal wear on the components. The utensil could only be inserted and removed

when the pin piece was in a neutral position. In addition, it only rotated in one direction in 45 degree

increments and produced a loud clicking noise with each rotation. The team’s objectives for the

semester were to increase the durability of the device by introducing a new rotation mechanism,

increase the versatility of utensils that could be inserted into the device, and to increase the security

of the utensil within the device to reduce wiggling.

The team implemented a new rotation mechanism to freely rotate a utensil 360 degrees in both

directions to any desired angle and to increase the durability of the device. The new rotation

mechanism was applied through two different prototypes. The first included a mechanism by which

a key block on the terminal device fit into a key hole on a separate piece attached to the client’s

opposite wrist. The second prototype excluded the key hole piece and instead included an attachable

wheel on the bottom of the key block. The client could roll the wheel on the base of the device on his

opposite hand to easily rotate the utensil to a desired position. The client preferred the roller device

as the turning motion required for the key block model was too strenuous on his shoulder.

Additionally, to increase utensil versatility and security, the team incorporated medical foam and

widened the pin to keep utensils in place and to accept a greater variety.

The client and the sponsor have both showed high satisfaction with the solution that the final

design proposes. Further additions to the design could over-complicate an overall simple design for a

complex problem. If improvements are made, a rest for the clients thumb could be implemented. The

team attempted to create a thumb rest, but it was too uncomfortable for the client so it was removed.

A new version could be created that better suit the customer needs. In addition, the ABS plastic

primarily used in the design’s structure is able to be 3D printed and is durable and cost effective;

however, higher quality materials could be used to increase the longevity of the device even further.

Lastly, other materials could be added to the device to increase friction of the rotation mechanism.

The team discussed with the sponsor the potentiality of marketing the device in the future. Four

main considerations were formulated. The first was coating the roller wheel with rubber dip instead

of Dycem. The second was coating the foam with latex instead of superglue. Both the first and

second considerations would speed up the manufacturing process and eliminate tedious tasks that

currently exist. The third consideration was selling the device with differently shaped wheels (i.e.

smoothed versus spoked). Depending on the condition, potential customers who would be using this

48

device could vary in their mobility and find one wheel easier to use than another. The final

consideration made by the team and the sponsor was selling the device along with a specific fork and

spoon. By doing so, the device would be guaranteed to securely hold this set of utensils, despite

being fairly versatile with others on the market.

In conclusion, the roller device and was customized to fit the client’s specific needs. The team

made adjustments to the device’s dimensions to make the rolling mechanism more comfortable and

convenient. The new device is easy to use, durable, and quiet, while offering multidirectional

rotation in 360 degrees. Furthermore, it includes no neutral position necessary for insertion and

removal of the utensil, and it secures utensils of all sizes. The total cost to manufacture the final

design is ~ $40.00. The client is happily using this device as of April 2015 for daily meals both at

home and in public.

* The team would like to note that Marty made a last minute request to remove the dropdown

extension piece on the outer casing. After he began to use the device, he decided that he could not

get used to the device being further away from his palm. As a result the team provided him with a

new device without the dropdown piece to satisfy his needs. CAD drawings of the assembled model

without the dropdown piece can be seen in Appendix K.

11.0 Self-Assessment (Design Criteria Satisfaction)

11.1 Customer Needs Assessment

Throughout the entirety of the project, our team has focused on refining and satisfying the needs

of our customer. Our number one priority was to make the device easy to use for our client. In

addition, we focused our efforts on the functionality and durability of the device. To self-assess our

team on meeting these customer needs, 9 out of 10 would be appropriate. From an ease of use

standpoint, the device allows the user to insert and remove silverware almost effortlessly. Once the

silverware is inserted, the utensil can be rotated with a minimal amount of work by rolling the wheel

along the customer’s opposite hand. The functionality of the device has also been met. The fork and

spoon holder allows various sizes of utensils to be held securely while still being able to rotate the

way it was designed. The removal of gearing previously used to rotate the device has also made the

device much more durable than previous designs. All in all, the customer needs have been met on a 9

out of 10 basis; the device satisfies all needs with the exception that all designs can be improved.

11.2 Global and Societal Needs Assessment

As stated in Section 11.1, our team has made our client, Marty, our main priority. His happiness

with us and with our device was extremely important to our project’s success. We prioritized

listening to his needs and noting each one because our team truly wanted to provide him with a

device that he would enjoy using by the end of the semester. Because we kept Marty always at the

front of every new design choice, we excelled in meeting the basic human needs and safety for the

project. Additionally, we found ourselves solving problems involving bioethics. At times Marty

would suggest problems with the design that were very specific for his needs - sometimes these

suggestions would cause us to start from scratch (i.e. a new method for smooth multidirectional

rotation) or make changes that could put us weeks behind as a team (i.e. a method for lowering or

raising the utensil). As a team facing these challenges, we had to weigh the pros and cons and make

the most ethical choice for Marty and for ourselves - what was worth the risk, time, and money

49

versus what was not. Could we still provide Marty with a device that satisfied most of his needs, and

kept us from failing as a team? We overcame those bioethical issues, and succeeded. Unfortunately,

we failed to think much about the environment. We printed over $500 worth of plastic throughout

our prototyping stage, utilizing energy and material that might not have been as necessary if we were

more careful and tedious with our concept generations and modifications. As a result of it all, our

team would give ourselves 9 out of 10 for meeting global and societal needs.

References

[1] NIH, “Charcot-Marie-Tooth Disease Fact Sheet,” National Institute of Neurological Disorders

and Stroke. June 2013.Retrieved February 5, 2015 from

http://www.ninds.nih.gov/disorders/charcot_marie_tooth/charcot-marie-tooth_fs.pdf,

[2] POSNA, “Charcot-Marie-Tooth Disease,” American Academy of Orthopaedic Surgeons. Feb.

2014. Retrieved February 5, 2015 from

http://orthoinfo.aaos.org/topic.cfm?topic=A00706

[3] Milton S. Hershey Medical Center, “Support Groups,” 2013. Retrieved February 5, 2015 from

http://www.pennstatehershey.org/web/guest/community/classessupportgroups

[4] Palmar Clip ADL Cuff. Retrieved February 2, 2015, from

http://www.alimed.com/palmar-clip-adl-cuff.html

[5] Fabrication Enterprises Utensil Holder. (n.d.). Retrieved February 2, 2015, from

http://www.devinemedical.com/Fabrication-Enterprises-Inc-61-0112

Utensil-Holder-p/fab1-61-0112.htm

[6] Utensil Holder With Elastic Opening. (n.d.). Retrieved February 2, 2015, from

http://healthproductsforyou.com/p-28265-utensil-holder-with-elastic

opening.html

[7] Grip Solutions Hand Grip. Retrieved February 2, 2015, from

http://www.wrightstuff.biz/grip-solutions-hand-grip.html

[8] Right Angle Utensil Pocket. Retrieved February 2, 2015, from

http://www.allegromedical.com//daily-living-aids-c519/right-angle-pocket

[9] Utensils. Retrieved February 2, 2015, from

http://www.especialneeds.com/dining-utensils.html?page=2

[10] iArm. Retrieved February 2, 2015, from

http://www.assistiveinnovations.com/index.php/en/ourproducts/robotics/iarm

50

Appendices Appendix A: Patent Descriptions

The following patents are relevant to the Penn State fork and spoon devices:

1) US 3288115 A: Ball-point pen mechanism

This patent describes a ball-point pen mechanism, and more importantly, the concept of

protracting and retracting the ink cartridge within it. This patent is relevant to the past design

because the rotating mechanism of the utensil is based on the protracting and retracting

events that occur with a retractable pen.

2) US 5630276 A: Eating utensil

This patent describes an eating utensil that is made for people with disabilities so that they

can feed themselves. It maintains the idea of a self-leveling spoon. This patent is relevant

because the idea for the internal rotating hardware is based off of the gears in this eating

utensil.

3) US 659341 A: Self-leveling spoon

This patent describes a utensil’s ability to self-stabilize. Due to its weighted bottom, the bowl

of the spoon maintains its level when the device is held. This patent is relevant because the

clamp with which the utensils are fastened is similar in shape to the self-leveling spoon.

4) US 4389777 A: Eating utensil for use by the manually impaired

This patent describes a device that allows a utensil to be secured into an instrument base.

This patent is relevant the entire attachment concept of the past design is based on this

invention.

5) US 2012147 A: Chuck operating key

This patent relates to the key and chuck mechanism seen in drills. The invention involves

inserting a key into a chuck, causing rotation within the drill. This patent is relevant because

it explains the concept that the rotating mechanism is based off of for the new design.

6) US 1136839 A: Car wheel

This patent describes a car wheel that rotates when a center bar, perpendicular to the wheel,

is moved by inner mechanics of the car. As far as the art-function matrix goes, this patent

affects the mechanical, aesthetic, and technical design of the device.

Patents 1 through 4 are relevant to the past fork and spoon device. Patents 2,3, and 5 are relevant

to the new fork and spoon device. Patent 6 is relevant to the rolling rotation mechanism.

51

Appendix B: Detailed Existing Product Summary

These are the major assistive eating devices currently on the market today. Each one is classified

as a cuff, adaptive utensil, or robot. The prices are listed if applicable and available.

1) Alimed - “Palmar Clip ADL Cuff” [4]

Classification: Cuff

Cost: $25.75 This device is a strapless device that slides onto the hand

and uses spring action to hold utensils. The pivoting

pocket permits more effective utensil position than

devices with a fixed pocket.

2) Fabrication Enterprises – “Utensil Holder” [5]

Classification: Cuff

Cost: $5.00

This device is an eating aid for people who have trouble

grasping and holding small utensils. The spring action

plastic clip fits the hand snugly without pinching, and

the utensil is held in a fixed position through a slit in the

cuff fabric.

3) “Utensil holder with elastic opening” [6]

Classification: Cuff

Cost: $12

Allows all utensils with hooks to be inserted into the

cuff. The Velcro hook and loop provide easy closure.

The beige cotton webbing is durable for long-term use.

52

4) Grip Solutions – “Hand Grip” [7]

Classification: Cuff

Cost: $37.95

The material of the device is a no slip, non-sticky one.

There are four different slits of various sizes, which

eliminate the need to ever have to adjust. It can fit a

variety of items, ranging in size from a pen to a

hairbrush.

5) “Right Angle Eating Utensil” [8]

Classification: Cuff

Cost: $20

This device allows an inserted utensil to be positioned at

a right angle to the palm. It accommodates standard

eating utensils, but not all sizes. The device is fabricated

using a combination of leather and metal materials. It is

one of the only products on the market that allows the

user to have some angled movement while eating.

6) “Assistive Dining Utensils” [9]

Classification: Adaptive utensils

Cost: $10 per set (on average)

These devices have large grips, creating an easy hold.

Many are designed for people with unsteady hands or

arthritis. Some utensils come angles, while others do not

– it all depends on the product brand.

53

7) Assistive Innovations – “iArm” [10]

Classification: Robot

Size: $100s-1000s

iArm is a robotic assistive eating device. In order to

move the hand around, the user needs to control a

joystick to feed oneself. The spoon used in the device

is customized and cannot be changed. It is a big,

black, bulky piece of equipment used by many

confined to wheelchairs.

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Appendix C: Budget Table

Item Cost (Dollars)

Bill of Materials 112.30

Prototyping 541.84

3D Printer Usage 541.84

Travel 192.25

Poster 65

Total 911.39

Appendix D: Bill of Materials

Item Number Description Vendor Quantity

Cost per

Item

(Dollars)

Total Item

Cost

(Dollars)

10333024

Suction Cup

Combo Michaels 1 3.49 3.49

10597609 Foam Sheets 12x18 Michaels 1 0.99 0.99

46232

Velcro 3/4"x12'

black Lowes 1 8.97 8.97

1037357

Kunin 9x12 white

felt Jo Ann 2 0.49 0.98

xprd821459 Darice 9x12 foamie Jo Ann 1 0.89 0.89

zprd_04700415a

Darice 9x12 ex

thick black Jo Ann 1 1.99 1.99

8514721 Suzh navy sd solid Jo Ann 1 2.12 2.12

5734272

Nipk swimwear

lining nude Jo Ann 1 1.25 1.25

13856687

Nipk confetti multi

ity k Jo Ann 1 1.31 1.31

50-1560B

Dycem non-slip

adhesives strips

(16"x1-1/8) Amazon 1 13.99 13.99

56060984

Memorex CDs (10

pack) Target 1 6.35 6.35

538301 Plasti-dip spray Lowes 1 6.34 6.34

75815116031 Plasti-dip liquid

Home

Depot 1 7.40 7.40

N/A Shipping of device FedEx 1 56.23 56.23

Total 112.3

55

Appendix E: Gantt Chart

56

Appendix F: Resumes

57

58

59

60

61

Appendix G: Deliverables Agreement

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Appendix H: Design Changes since the SOW Report

Engineering Specifications

Table H.1: Revised Target Specifications and Values

Metric Importance Target Value Units

Cylinder Length 6 9.2 cm

Cylinder Outer Diameter 1 2.8 cm

Cylinder Inner Diameter 1 2.6 cm

Top Cap Length 1 1.8 cm

Top Cap Outer Diameter 1 3.5 cm

Top Cap Inner Diameter 1 3.2 cm

Bottom Cap Length 1 1.8 cm

Bottom Cap Outer Diameter 1 3.5 cm

Bottom Cap Inner Diameter 1 3.5 cm

Key Block Length 5 3.5 cm

Key Block Width 5 1.5 cm

Key Block Thickness 9 2 cm

Key Hole Length 5 3 cm

Key Hole Width 5 1.5 cm

Key Hole Thickness 9 3 cm

Pin Length 3 8 cm

Pin Width 7 3 cm

Concept Generation and Selection

During initial testing with the client of the key hole and block prototype, it was found that the

client could use the rotation mechanism successfully when the key hole was attached to the opposing

hand. However, the amount of work that the client had to put in did not result in fast enough rotation.

The client expressed that with the amount of shoulder force needed to rotate the utensil just a small

amount he would lose stamina. The team decided to find a way to rotate the utensil with less effort.

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During testing with the client, an idea was generated to possibly add a rubber wheel to the bottom of

the device for easy rotation. The client could easily roll the device along the table edge or on the side

of his pant leg to adjust the angle of the utensil. The team had the client practice this motion of

rolling the terminal piece along the table, and the client expressed great interest in this prototype

design. A sketch of the rolling wheel concept can be seen in Figure H.1.

Figure H.1: A rolling wheel attachment on the base of device to increase ease of utensil

rotation and eliminating unnecessary shoulder force.

Another issue that was brought up during discussion with the client was that his thumb drags in

his food while eating due to the positioning of the device on the splint. The team suggested

extending the device and possibly lowering the device away from the splint so that the client can

place his thumb on top of the piece while eating to reduce dragging. The thumb would rest more

naturally on top of the device and would also help reduce wiggling of the utensil by helping to hold

the fork in place. Figure H.2 shows the team generating this concept with the client and determining

how long to extend the device to solve this issue.

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Figure H.2: Client’s thumb drags in food. The team measured how much to elongate the

terminal piece to address this issue.

As stated above, the client had a difficult time rotating the utensil with the key hole and block

design due to deteriorating shoulder strength. When discussing initial testing of this prototype with

the sponsor, the team (including the sponsor) decided to continue to simultaneously work on

improving the key hole and block prototype as well as designing the new roller prototype. The

sponsor sees promise in the key hole and block design for other patients that are not as far along in

the progression of the disease. During testing with the client, the Velcro straps that attached the key

hole piece to the opposing hand were not tight enough to stop the device from moving around on the

hand. The team came up with a design idea to place the device on the side of the wrist, which would

be more of a natural position for the client. In addition, if this piece was designed to fit over the side

of the wrist in a semi-circle shape, the piece would not be able to slide around during use. A sketch

of this design concept is seen in Figure H.3.

Figure H.3: Block piece moved to the side of the wrist to reduce wiggling during use.

The two pin inserts were also tested during the meeting with the client. The fabric pin was too

difficult for the client to insert utensils. This concept has therefore been eliminated from future

65

design plans. The tapered pin accepted and held some utensils during testing; however, with the

foam inserts, the pin did not accept the client’s thickest utensil. To address this issue, the team will

increase the pin gap to accept thicker utensils.

System Level Design

The pin insert was modified to allow a wider range of utensils to fit inside the prongs and can be

seen in Figure H.4. By widening the overall gap from 2 mm to 5 mm, almost all thicknesses of

silverware should fit inside the prongs. Open-cell foam will be added to the inside of one or both

pins to mold around the silverware and hold the utensil more securely. By using foam that can be

easily compressed, the insertion and removal of the silverware also becomes much easier.

Figure H.4: Widened pin with added room for foam inserts.

The key block device was modified to improve ease of use and functionality. The outer shell was

extended 20 mm to allow the user’s thumb to rest on top of the device. With the previous shorter

design, the user’s thumb rested underneath the device and often came in contact with food on the

plate. To compensate for the additional 20 mm length of the shell, the upper piece of the key block

was extended by 20 mm. The key hole attachment was also redesigned to offer better usability. The

radial arc was ergonomically redesigned to be placed on the inside of the user’s wrist. The key hole

was extended to provide a deeper pocket for the key block could be inserted and rotated. These

adjustments can be seen in Figure H.5.

Figure H.5: Exploded view of key block device

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When testing, a slightly different prototype was generated. This design does not use a key block

system, but rather a roller. The terminal device is essentially the same, except that the square bottom

of the key block is traded for a round cylinder. This cylinder is then locked into the hole in the wheel

piece. To rotate the inner pin, the user pushes the wheel against the edge of a table or pants leg, and

moves the device laterally in either direction. By adding Dycem to the wheel, the friction

encountered between the wheel and table edge or pant leg induces rotation when moved laterally.

This system reduces fatigue, as well as significantly enhances ease of use. This design can be seen in

Figure H.6 below.

Figure H.6: Exploded view of wheel device

67

Appendix I: Design Changes since the DSR

Engineering Specifications

Table I.1: Revised Target Specifications and Values

Metric Importance Target Value Units

Cylinder Length 6 6.4 cm

Cylinder Outer Diameter 1 2.8 cm

Cylinder Inner Diameter 1 2.6 cm

Cylinder Extender Piece 5 1.0 cm

Top Cap Length 1 1.8 cm

Top Cap Outer Diameter 1 3.2 cm

Top Cap Inner Diameter 1 2.9 cm

Bottom Cap Length 1 1.6 cm

Bottom Cap Outer Diameter 1 3.5 cm

Bottom Cap Inner Diameter 1 3.5 cm

Pin Length 6 14.5 cm

Pin Width 7 2.4 cm

Pin Square Attachment Block 5 1.0 cm

Roller Wheel Diameter 5 3.2 cm

Concept Generation and Selection

After initial testing with the roller mechanism prototype, the client was very happy with the

design. The team had both extended the device and added a dropdown piece to allow the user’s

thumb to rest more comfortably on top of the device to avoid dragging in food. Instead of solely

resting on top of the cap piece of the device, the team considered designing a thumb rest for the user

to place his thumb into. This thumb rest would be attached to the cap and would resemble a J-hook.

A basic sketch of what this concept would look like is shown below in figure I.1.

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Figure I.1: Sketch of thumb rest concept

The team designed this thumb hook in SolidWorks and 3D printed a modified cap in the Learning

Factory. During client assessment of the thumb rest prototype, the team discovered the client’s

thumb was locked in a position that made using the thumb rest too uncomfortable. The thumb rest

was also too brittle due to being thin and extruded from the device. A SolidWorks model of the

thumb rest prototype can be seen in Figure I.2 below. The client decided against a thumb rest and

would rather just rest his thumb on top of the device.

Figure I.2: SolidWorks model of thumb rest roller prototype

System Level Design

The final design of the fork and spoon holder is shown below in Figures I.3 and I.4. A few

changes were made from preliminary prototypes to enhance the ergonomics and functionality of the

device. The device now consists of just 4 pieces in total. A dropdown was added to the outer shell to

extend the device a few centimeters from the user’s palm. This would allow for the user’s thumb to

rest above the device when in use, keeping the thumb clear of any contact with the contents of the

plate. This dropdown was made hollow as opposed to solid in order to make the device lighter and to

reduce material and cost. The shell was also shortened, to provide a better angle for when the client

uses a stabbing motion. The shorter the shell, the less the client has to raise his shoulder to provide

the right angle to stab a piece of food. The inner pin and lower cylinder were combined into one

piece for two reasons. For one, the reduction in the number of pieces makes the design simpler, in

addition to removing the need for any gears-a possible mechanism for failure. The slot in the pin has

69

also been extended to allow the utensil to be inserted farther. This extra length within the slot not

only holds the utensil more securely, but further aids in reducing the stabbing angle needed by the

client. Medical grade T-foam is cut and inserted into the pin to compress the utensil against the

opposite wall of the pin. The smooth adhesive backing on one side of the foam allows for the utensil

to be inserted and removed easily, while still compressing the utensil when fully inserted. The

bonding of the wheel and inner pin has also been modified. The wheel and lower cylinder now use a

square shape to join the two pieces. This will prevent any slippage between the wheel and pin,

keeping a constant connection between the wheel, pin, and ultimately the utensil.

Figure I.3: Exploded view of final prototype

Figure I.4: Assembled view of final prototype

70

Appendix J: Past CAD Drawings

Figure J.1: Assembled specification drawing of key block device (mm)

Figure J.2: Assembled specification drawing of wheel device (mm)

71

Figure J.3: Specification drawing of shell (mm)

Figure J.4: Specification drawing of the cap (mm)

72

Figure 23: Specification drawing of cap

Figure J.5: Specification drawing of cylinder key block (mm)

Figure J.6: Specification drawing of square key block (mm)

73

Figure J.7: Specification drawing of pin insert without foam (mm)

Figure J.8: Specification drawing of key hole wrist piece (mm)

74

Appendix K: Final CAD Drawings

Figure K.1: Assembled specification drawing of final roller device with extender piece (mm)

Figure K.2: Specification drawing of final roller device outer shell with extender piece (mm)

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Figure K.3: Specification drawing of final roller device pin (mm)

Figure K.4: Specification drawing of final roller device cap (mm)

76

Figure K.5: Specification drawing of final roller device round wheel (mm)

Figure K.6: Specification drawing of final roller wheel device spoked wheel (mm)

77

Figure K.7: Assembled specification drawing of final roller wheel device without extender

piece (mm)

Figure K.8: Specification drawing of final roller device outer shell without extender piece

(mm)