Wind Turbine Design Report FINAL

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Wind Turbine Design

Report

Members:Matthew Boles

Caleb Henry

Eric Romanowski

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Table of Contents

Introduction......................................................................................................................................1

Abstract........................................................................................................................................1

Customer Needs...........................................................................................................................2

Design Summary.............................................................................................................................3

Prototype One..................................................................................................................................4

Concept Generation and Selection...............................................................................................4

Base Design..............................................................................................................................4

Table 1: Base Design Decision Matrix.....................................................................................5

Blade Design............................................................................................................................7

Table 2: Blade Design Decision Matrix for Prototype One.....................................................7

Selected Design for Prototype One............................................................................................10

Final Assembly..........................................................................................................................11

Figure 1: Full assembled CAD Drawing - Prototype One.....................................................11

Square Base:...............................................................................................................................12

Figure 2: Square Base Drawing..............................................................................................12

Main Shaft..................................................................................................................................13

Figure 3: Shaft Drawing.........................................................................................................13

Motor Holder..............................................................................................................................14

Figure 4: Motor Holder Drawing...........................................................................................14

Motor..........................................................................................................................................15

Figure 5: Motor Drawing.......................................................................................................15

Tri-Force Blade..........................................................................................................................16

Figure 6: Tri-Force Blade Drawing........................................................................................16

Prototype Two...............................................................................................................................17

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Concept Generation and Selection.............................................................................................17

Blade Design..........................................................................................................................17

Table 3: Blade Design Decision Matrix for Prototype Two..................................................18

Selected Design for Prototype Two...........................................................................................19

Final Assembly..........................................................................................................................20

Figure 7: Full assembled CAD Drawing – Prototype Two....................................................20

Square Base................................................................................................................................21

Figure 8: Square Base Drawing..............................................................................................21

Main Shaft..................................................................................................................................22

Figure 9: Main Shaft Drawing................................................................................................22

Motor Holder..............................................................................................................................23

Figure 10: Motor Holder Drawing.........................................................................................23

Motor Attachment......................................................................................................................24

Figure 11: Motor Attachment Drawing..................................................................................24

Adapted Water Wheel Blade......................................................................................................25

Figure 12: Adapted Water Wheel Blade Drawing.................................................................25

Prototype Three.............................................................................................................................26

Concept Generation and Selection.............................................................................................26

Base Design............................................................................................................................26

Table 4: Base Design Decision Matrix for Prototype Three..................................................27

Blade Design..........................................................................................................................28

Table 5: Blade Design Decision Matrix for Prototype Three................................................28

Selected Design for Prototype Three.........................................................................................30

Final Assembly..........................................................................................................................31

Figure 13: Full assembled CAD Drawing - Prototype Three.................................................31

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Square Base................................................................................................................................32

Figure 14: Square Base Drawing............................................................................................32

Base Supports.............................................................................................................................33

Figure 15: Base Support #1 Drawing.....................................................................................33

Figure 16: Base Support #2 Drawing.....................................................................................33

Support Tail................................................................................................................................34

Figure 17: Support Tail Drawing...........................................................................................34

Main Shaft..................................................................................................................................35

Figure 18: Main Shaft Drawing..............................................................................................35

Torque Support..........................................................................................................................36

Figure 19: Torque Support Drawing......................................................................................36

Motor Mount..............................................................................................................................37

Figure 14: Motor Mount Drawing..........................................................................................37

Swept Tri-blade..........................................................................................................................38

Figure 20: Swept Tri-Blade Drawing.....................................................................................38

Test Performance for Prototype One.........................................................................................39

Test Performance for Prototype Two.........................................................................................40

Test Performance for Prototype Three.......................................................................................41

Conclusion.....................................................................................................................................42

Budgets..........................................................................................................................................43

Budget for Prototype One..........................................................................................................43

Table 6: Budget for Prototype One........................................................................................43

Budget for Prototype Two..........................................................................................................43

Table 7: Budget for Prototype Two........................................................................................43

Budget for Prototype Three........................................................................................................44

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Table 8: Budget for Prototype Three......................................................................................44

Mass of Turbine.............................................................................................................................45

Mass of Turbine Prototype One.................................................................................................45

Table 9: Mass of Turbine One................................................................................................45

Mass of Turbine Prototype Two................................................................................................45

Table 10: Mass of Turbine Two.............................................................................................45

Mass of Turbine Prototype Three..............................................................................................46

Table 11: Mass of Turbine Three...........................................................................................46

Appendices....................................................................................................................................47

Appendix A: Generator Specifications......................................................................................47

Appendix B: Measured Wind Speeds........................................................................................48

Works Cited...................................................................................................................................49

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IntroductionThis section will introduce the Wind Turbine Project. This includes the abstract and the customer

needs which forms the basis of the project.

Abstract

The problem that must be addressed is the design and construction of a wind turbine that

is light, inexpensive, and effective at producing power. The first prototype has been based on

similar designs used within the industry using a singular tower and the generator mounted at the

top of the structure with the propeller. The goal of the first prototype was to mimic the

effectiveness and strength of the most commonly produced wind turbine. The cost of the first

prototype would cost approximately $8.54. The total mass of the wind turbine was

approximately 284.6 grams. The base of the wind turbine was very effective. This means that it

did not falter throughout the duration of the three minute test. The blades, however, only created

a maximum of .0014 watts, which is very inefficient. The first prototype would not be

recommended due to a lack of power produced and a large cost compared to the poor power

output.

The second prototype was based on a paddle boat paddle system which was thought to be

very productive at utilizing air to turn the generator. While the second prototype succeeded at

reducing the cost, it added both weight and reduced the number of watts produced. The total cost

of the turbine was $3.93 which is much better than the first prototype. The total mass of the

second turbine was approximately 361.0 grams. It produced a lower amount of watts producing

only .00051 watts which is much less than the first prototype. The second prototype would not be

recommended due to a large mass and very low power output.

The third prototype used a swept tri-blade design that was based on the first prototype but

with a way to catch and utilize more wind to its advantage. The third prototype improved every

aspect of the turbine and thus the group recommends this prototype be used. The turbine mass

totaled only 254.4 grams which is lighter than the previous turbines while not compromising

stability. The cost was also much less than the previous turbines, totaling only $3.18 which is

one-third of the second prototypes cost. It also improved upon the power output, outputting .615

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watts, which is approximately a 500% increase from the first prototype. It is for the decrease in

cost, weight, and an increase in power output that the group recommends the third prototype.

Customer Needs

The customer requires a wind turbine that is freestanding, functions without issue for

three minutes, and generates power. The customer is also interested in three other aspects that

should be incorporated into the design of the turbine. The turbine should be lightweight which

will help the customer transport and set up the wind turbine. It should also have a low cost which

will allow the customer to purchase more wind turbines or increase profitability of the purchased

turbines. Last but not least, the turbine should have a high efficiency which will allow for fewer

turbines to be required, thus saving the customer money. Part of the turbine should also be built

using either a 3D printer, the Torchmate, or the laser cutter.

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Design SummaryThe purpose of the design summary is to address the design of the prototypes and explain

the decisions pertaining to the aspects of the turbine. The design summary contains all possible

solutions that were considered and the reasoning that the designs were chosen and the potential

effectiveness to the overall design. It includes both the entire base design as well as various blade

designs that were considered to be potential contenders to be included in the first design

prototype.

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Prototype OneThis section will discuss all aspects pertaining to prototype one.

Concept Generation and Selection

The purpose of the concept generation and selection is to eliminate potentially poor

design ideas before they are attempted as prototypes. Thus, this section will focus on various

ideas, many of which are not incorporated in the prototype.

Base Design

The group has decided to make a decision matrix considering the following elements:

constrains blade possibilities, cost, simple assembly, stability, and weight. The base should allow

for multiple different types of fan blades, but if the base lowers the choices of blades, then it

loses value. Cost is also highly rated because the higher the cost for the producer; the higher the

cost for the consumer. A simple assembly, simple meaning quick and does not require much

effort to build, will allow for us to develop more prototypes in less time if the idea does fail.

Stability is the most valuable element to our decision matrix. The project will fail immediately if

the project topples and falls. This structure and its strength begins at the base. Weight is another

important factor in the group’s decision matrix. The less the structure weights; the easier it will

be to transport the turbine.

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Table 1: Base Design Decision Matrix

Decision

Matrix

Idea 1 – Long

quad base

Idea 2 –

Pyramid base

Idea 3 –

Wire

Idea 4 – Big Circle,

Little Square

Constrains Blade

Possibilities/Motor Mount - 15

2 3 4 4

Cost – 20 4 3 3 4

Simple Assembly – 15 4 2 3 4

Stability – 25 2 4 4 3

Weight – 20 4 3 4 4

Total Points 300 295 355 355

Idea one scored 300 points overall. The aesthetics of the base are standard to a wind

turbine and thus scored in the middle of the rubric. In terms of motor mounting capabilities, it

scored below average due to a limited amount of mounting options. This is in contrast to the

cost, which is relatively low, allowing it to score high. It also scored high in simplicity due to the

cross base design and the few pieces required. It did, however, score low for stability because of

the lack of area covered and few supports preventing wobbling, though the weight scored a four

because of the few pieces needed.

Idea two scored 295 points overall. It had acceptable mounting abilities for the motor.

Due to the extra material needed for the pyramid, it has an average cost compared to the others.

Due to the more complicated design of the base, it scores a 2 on the ease of assembly. It is

because of the extra material, however, that it scores well with stability due to it taking less space

to be stable, which also is a downside for the weight, which is at an average projection.

Idea three scored the highest with 355 points overall. It has an above average amount of

motor mounting options. It also features average cost and assembly specifications due to the

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amount of parts involved in the structure. The wire design does feature exceptional stability and

a low weight from the hollow base and rectangle design.

Idea four scored the highest as well with an overall score of 355. The number of motor

mounting positions placed it around average adaptability. Because of the large amount of

material used, it had an average low cost though it features a simple assembly, being a base with

a pole, allowing it to score high in that regard. Both the stability and weight were scored as

above average because of the size of the base, though those features contribute to the positive

attributes of the design (Contech Engineered Solutions n.d.).

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Blade Design

To determine the best blade, a decision matrix has been created considering the following

elements: adaptability, cost, simple assembly, projected efficiency, and weight. The adaptability

of a blade is important because it can allow for various arrangements as well as allowing the base

to change around it. The cost is also important to consider because it can be a determinant of

whether the customer will choose to purchase the wind turbine. A simple assembly can allow

maintenance to be done fast as well as allow a company to build more turbines in less time. The

efficiency of the system, and thus the blades, are easily the most important aspect of a turbine

because it allows the motor to generate the most power. The weight is also important for all

aspects of the machine because it affects the ability to transport the turbine as well as adds extra

unneeded force to the base.

Table 2: Blade Design Decision Matrix for Prototype One

Decision

Matrix

Idea 1 – Tri

Blade

Idea 2 – River

Wheel

Idea 3 – Flat shovel

blades

Idea 4 – Curved

Shovel

Adaptability - 15 3 1 3 3

Projected Cost - 20 4 1 2 3

Simple Assembly –

15

4 4 3 3

Efficiency - 25 4 3 2 3

Weight – 20 4 1 2 3

Total Points 365 190 220 285

The adaptability of the blades is important because of the implications it can have on the

base and the efficiency of the turbine. Idea one, three, and four scored in the middle of the

possible points for adaptability because while they can be slightly adjusted after being built and

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tweaked without much effort, the designs do not have the ability to conform immediately to the

group’s desire. Idea two scored the lowest out of the four designs due to it needing a specific

base and can only have an orientation in relation to the base.

Cost of a machine is also important to consider while building a wind turbine and the cost

of the propeller can be a significant cost that will eventually be passed down to a consumer.

Assuming all ideas were to be produced of the same material, the least costly idea would be idea

one because of the lack of material that would be used in the production. The next least costly

idea would be number four because the propeller's fin density would not be as high as the

remaining two options. Ideas two and three come in a close last and second to last place due to

the extra material that is used with each design, thus exponentially increasing the cost of both

propellers.

A simple assembly of the propeller to the base is very important to the overall design of

turbine because it allows for changes to be made quickly and without money being lost to time.

Both idea one and two’s propellers are relatively easy to assemble due to a simpler design which

is horizontal in nature. Ideas 3 and 4 are somewhat more complicated due to a vertical mounting

system which can complicate the overall base design.

The projected efficiency is possibly the most important aspect of the design because it

determines the power output by the motor. The tri-blade design is regarded as one of the most

efficient designs within the wind turbine industry and thus scored the highest out of the four

ideas (Gurit n.d.). Idea three and four closely follow with idea two being based off of an old

steam boat propeller, it would not face as much opposing wind thus increasing its efficiency over

the remaining two designs. Idea four would also be efficient due to the curve of the blade,

allowing the opposing air flow to pass over it with more ease than a non-curved blade. Idea three

scores very low due to the straight edge of the blade which causes more air disruption and also

catches more opposing air, reducing the effectiveness of the design.

The weight of the propeller is a determinant factor to the design of a propeller because of

the implications it has, not only structurally, but also when the turbine has to be transported. Idea

one scored the highest in the weight category due to the lack of material that is used. Idea four is

similar to idea one but uses slightly more material in comparison, as does idea three in

comparison to idea four. Idea two, however, would be the heaviest because of the extravagant

design that uses much more material than the others.

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The first prototype tested used the Tri Blade design due to it having a projected high

effectiveness for producing power.

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Selected Design for Prototype One

The purpose of the Selected Design Concept Discussion is to describe the proposed plan

to develop our first prototype. This section will discuss the square base, the shaft, the motor

holder, the motor, and the Tri-Force Blade design.

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Final Assembly

Figure 1: Full assembled CAD Drawing - Prototype One

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Square Base:

Figure 2: Square Base Drawing

The square base is a simple portion of the design. The shape will allow for equal

balancing in all directions. In the case that the motor needs to be rotated to catch a wind, the

square base will pose no threat to a change in direction. The square will be created out of half

inch cardboard. We expect that the price of a full 30” X 40”cardboard sheet is $1.69 from

Utrecht Art Supplies (Utrecht n.d.). Though the design is simple, the large size of the lofty

material will allow it to prevent tipping in the winds.

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Main Shaft

Figure 3: Shaft Drawing

The shaft is a hollow cylinder that is designed to fit directly into the center of the square

base. This piece will be made of 3/4 thick PVC. The piece is 431.8mm to catch the strongest

winds that was recorded in the wind speed table. This part weighs enough to hold the cardboard

square down, but not enough to destabilize the generally low weight turbine. The PVC pipe has

been purchased through PVC Fittings Online for $3.91 (PVC Fittings Online n.d.). The

cylindrical shape of the PVC shaft will allow for winds to bend around the structure unlike a

rectangular face. This will benefit overall stability in the base and will not hamper the wind

speeds on the turbine blades.

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Motor Holder

Figure 4: Motor Holder Drawing

The motor holder was designed for the purpose of transitioning a PVC pipe into a

comfortable setting for the motor. The motor holder fits directly into the PVC pipe hole and

snuggly fits the motor directly into the slot. The motor holder will be created out of ABS plastic

using a 3-D printer, which will fufill our machine use requirement. ABS plastic costs

approximately $30 per kilogram. The final product weighs 37.7g which would cost

approximately $1.13.

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Motor

Figure 5: Motor Drawing

The motor was measured so that it will have a perfect fit into the motor holder. The Tri-

Force blade used an interference fit to slide onto the motor’s axle. The figure shows a modeled

version of the motor that was provided for testing. Though the technical drawings look bare, two

wires stick out the rear end of the motor, so that they can be connected to a voltometer or another

power measuring utensil. This will remain the design for all remaining prototypes.

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Tri-Force Blade

Figure 6: Tri-Force Blade Drawing

The Tri-Force blade is very similar to designs commonly used in industry. The propeller

has been 3D printed out of ABS plastic to ensure a light weight and low cost. It has been

designed to have a curvature that can slice thorugh the air as well as catch the wind to produce

power. The Tri-Force Blade follows the same pricing for the motor holder at approximately $30

per kilogram. The blade’s mass is 13.9 grams so the total cost for the Tri-Force blade is $0.42.

These blades are low cost and low weight; they also are expected to have a generally high power

output due to the frequent usage of these blades.

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Prototype TwoThis section will discuss all aspects pertaining to prototype two.




ideas, many of which are not incorporated in the prototype. The group felt that the base did not

need modified or redesigned from prototype one and will remain the same for the second

prototype.

Blade Design











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Table 3: Blade Design Decision Matrix for Prototype Two

Decision

Matrix

Idea 1 – Adapted

River Wheel

Idea 2 – River

Wheel

Idea 3 – Flat

shovel blades

Idea 4 – Curved

Shovel


Projected Cost -

20

3 1 2 3

Simple Assembly

– 15

3 4 3 3

Efficiency - 25 4 3 2 3

Weight – 20 3 1 2 3

Total Points 310 190 220 285

Three of the original blade ideas remained from prototype one and a new one was

subsequently created and chosen. The adapted river wheel was scored higher than the original

river wheel design due to the potential for more mounting positions, a lower cost due to using a

material already in the design, as well as a higher efficiency than what was projected compared

to the original river wheel design. This provided average and above average scores for the blade

design allowing it to score a reasonable 310 points.

The adapted river wheel was designed with the intention of mimicking the design of the

original river wheel while adding additional blades and a minimal blade mounting system. This

lead the group to believe that not only will the weight be reduced, but also, cost be reduced, and

efficiency increased. This significantly increased the projected points for that blade design.

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Selected Design for Prototype Two

The purpose of this Selected Design Concept Discussion is to describe the proposed plan

to develop the group's second prototype. This section will discuss the square base, the shaft, the

motor holder, the motor, and the adapted water wheel blade design.

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Final Assembly

Figure 7: Full assembled CAD Drawing – Prototype Two

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Square Base


The square base is a simple portion of the design. The shape will allow for equal

balancing in all directions. In the case that the motor needs to be rotated to catch a wind, the

square base will pose no threat to a change in direction. The square will be created out of half

inch cardboard. We expect that the price of a full 30” X 40”cardboard sheet is $1.69 from

Utrecht Art Supplies (Utrecht n.d.). Though the design is simple, the large size of the lofty

material will allow it to prevent tipping in the winds. Hot glue is also needed for the construction

of the base which can be found at Walmart for $1.04.

ALL DIMENSIONS ARE IN MM.

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Main Shaft

Figure 9: Main Shaft Drawing

The shaft in prototype two is very similar to the shaft in prototype one. The main

difference is that its height is 15”. The group used the same 3/4” schedule 40 PVC pipe, because

of its acceptable cost and weight. The length of the PVC was changed to support the new blade

design and allow it to operate in the acceptable air flow region. The lowered height allowed for

the highest speed winds to only hit the top blade. Hot glue was used to fix the shaft into place.

The shaft’s mass is 119 grams. The PVC cost $1.29 for a 5’ 1” schedule 40 PVC pipe at

Menards.

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Motor Holder

Figure 10: Motor Holder Drawing

The motor mount in prototype two is also similar to the motor mount in prototype one.

This motor mount design was cut in size. This will help reduce both the cost and the weight of

the turbine as a whole. The motor mount is designed to fit snugly inside the PVC shaft opening.

The top of the mount allowed for the motor to slide into place and stay fixed with hot glue. The

motor mount was created out of ABS plastic and has a mass of nine grams. Using $30.00 per

kilogram, the motor mount cost $0.27.

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Motor Attachment

Figure 11: Motor Attachment Drawing

The motor attachment is a crucial component to the blade design. The motor shaft slides

directly onto either side of the hole in the center of the cylinder. The motor shaft attachment

gives the ability to transfer a very small shaft into a much larger, more applicable shaft. The shaft

attachment is made out of ABS plastic and has a total mass of 21 grams. The shaft costs $0.63

according to the pricing of $30.00 per kilogram of ABS.

ALL DIMENSIONS IN MM.

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Adapted Water Wheel Blade

Figure 12: Adapted Water Wheel Blade Drawing

The water wheel blade design consists of the shaft attachment and four long blades of

cardboard that would catch high winds one blade at a time. The blades were 12” long to catch the

strongest wind on the top blade, due to a short shaft design. This prevented the blades from

catching winds in two directions that opposed each other. The blades are made of cardboard and

are directly hot glued to the shaft attachment. With the shaft attachment, the blade had a mass of

99 grams.


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Prototype ThreeThis section will discuss all aspects pertaining to prototype three.




ideas, many of which are not incorporated in the prototype.

Base Design

The group has decided to make a decision matrix considering the following elements:

constrains blade possibilities, cost, simple assembly, stability, and weight. The base should allow

for multiple different types of fan blades, but if the base lowers the choices of blades, then it

loses value. Cost is also highly rated because the higher the cost for the producer; the higher the

cost for the consumer. A simple assembly, simple meaning quick and does not require much

effort to build, will allow for us to develop more prototypes in less time if the idea does fail.

Stability is the most valuable element to our decision matrix. The project will fail immediately if

the project topples and falls. This structure and its strength begins at the base. Weight is another

important factor in the group’s decision matrix. The less the structure weights; the easier it will

be to transport the turbine.

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Table 4: Base Design Decision Matrix for Prototype Three

Decision

Matrix

Idea 1 –

Long quad

base

Idea 2 –

Pyramid base

Idea 3 –

Wire

Idea 4 – Big Square,

Little Circle with a Tail

Constrains Blade

Possibilities/Motor Mount - 15

2 3 4 4

Cost – 20 4 3 3 5

Simple Assembly – 15 4 2 3 5

Stability – 25 2 4 5 4

Weight – 20 4 3 4 5

Total Points 300 295 370 435

Ideas one through three stayed the same due to the possibility of an improvement in the

design factors listed. They retained the same scoring as provided during prototype one because

of the lack of changes made to the base throughout the iterations between the first prototype and

the third.

A square design with a tail scored the highest with an overall score of 435. The number

of motor mounting positions placed it around average adaptability. Because of the large amount

of material used, it had an average low cost though it features a simple assembly, being a base

with a pole, allowing it to score high in that regard. Both the stability and weight were scored as

above average because of the size of the base, though those features contribute to the positive

attributes of the design and the thinner material which cost and weighed less while retaining the

minimum stability needed for the turbine (Contech Engineered Solutions n.d.). A change that

was made to the original design that was determined to be better is adding a stabilizer to the rear

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of the board. This enables an increase in stability though it minimally sacrifices some weight.

Cost is not affected due to the size of cardboard purchased.

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Blade Design











Table 5: Blade Design Decision Matrix for Prototype Three

Decision

Matrix

Idea 1 – Curved

Tri-Blade

Idea 2 – River

Wheel

Idea 3 – Flat

shovel blades

Idea 4 – Curved

Shovel


Projected Cost -

20

4 1 2 3

Simple Assembly

– 15

4 4 3 3

Efficiency – 25 5 3 2 3

Weight – 20 4 1 2 3

Total Points 390 190 220 285

Idea one was the only idea that changed due to the prototype 2’s blade not performing as

expected. A curved tri blade that absorbs more of the air and uses the force to push the blade is

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expected to be relatively adaptable to certain situations but is nowhere near excellent. The ABS

printed blade would be relatively cost efficient and would only require payment for the amount

of material necessary. This is in contrast to any other form of blade which may use excess

material which incurs additional costs. A curved ABS Tri-Blade also requires minimum

assembly allowing it to score highly in that category. Due to the swept front of the blade, it is

believed that the blade will provide maximum efficiency which gives it top marks in projected

efficiency. The lightweight nature of ABS gives the blade system a low projected weight

allowing it to do well in that category as well as become a top prospect due to not adding

unnecessary weight to the turbine design.

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Selected Design for Prototype Three

The purpose of this Selected Design Concept Discussion is to describe the proposed plan

to develop the group's third prototype. This section will discuss the square base, the shaft, the

torque support, the motor holder, the motor, and the swept tri-blade design.

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Final Assembly

Figure 13: Full assembled CAD Drawing - Prototype Three

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Square Base


The base design in prototype three has several small changes compared to prototype two.

For instance, the shaft hole is no longer in the center of the base, it has been moved so that the

main shaft was 2” from the front edge. The base is still made of cardboard and had a mass of

48.4 grams. The cardboard used for all cardboard pieces related to the turbine cost $0.62 from

Wal-Mart.

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Base Supports

Figure 15: Base Support #1 Drawing

Figure 16: Base Support #2 Drawing

The base potion of prototype three incorporated two different types of base supports. The

base supports uses cardboard and hot glue to attach to the rest of the base. The supports stack up

around the hole in the base to support the PVC pipe. The first support is the 4” by 4“ cardboard

base support. The next two supports uses 2” by 2” card board supports. Without these supports,

the PVC pipe would be less stable and thus could suffer failure. The total mass of the support is

5.6 grams. The hot glue costs totaled $1.04 from Wal-Mart. The cardboard used for the base

supports are of the same cardboard used for the base.



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Support Tail

Figure 17: Support Tail Drawing

The tail attaches to the center of the rear end of the base. The tail pushes up against the

wooden back stop so that the turbine can stand near the red line which also helps to increase the

stability of the turbine. The tail is connected to the base with hot glue and is composed of

cardboard. The mass of the tail is 10.7 grams. The cardboard used for the suport tail is of the

same cardboard used for the base.

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Main Shaft

Figure 18: Main Shaft Drawing

The shaft is a ½” schedule 40 PVC pipe. The shaft hot glues into the cardboard base and

base supports. The PVC pipe weighs just enough to keep the whole turbine down, and does not

have much unnecessary mass. The shaft has a mass of 129.2 grams. The cost for 2 feet of ½ inch

schedule 40 PVC is $1.26 which can be found at Menards.

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Torque Support

Figure 19: Torque Support Drawing

The torque support is a cardboard rectangle that attaches at approximately a 45º angle

from the base. The torque support resists motion from pushing the shaft backwards. The rotation

of the turbines shaft changed the angle at which the blade accepted wind. With the torque

support attached, the blade to catches more wind at the appropriate angle. The torque support has

a mass of 2.7 grams. The cardboard used for the motor mount is of the same cardboard used for

the base.

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Motor Mount

Figure 14: Motor Mount Drawing

The motor mount is simply comprised of cardboard. The center of the cardboard motor

mount hotglues to the top of the PVC shaft. Hot glue sufficiently holds the motor in place on top

of the motor mount. The end of the motor extends past the edge of the motor mount to support

free action of the blade. The mass of the motor mount is 0.6 grams. The cardboard used for the

motor mount is of the same cardboard used for the base.


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Swept Tri-blade

Figure 20: Swept Tri-Blade Drawing

The Tri-Blade design looks similar to the the Tri-Force blade design in the first

prototype. The main changes in the design mainly has to do with the size of the entire blade and

the size of each blade. The Tri-Blade is a very small blade and low density ABS plastic blade so

that the force of wind will allow for a faster angular velocity. The blades were also designed to

catch wind and rotate clockwise. The Tri-Blade attaches directly to the shaft of the motor. This

part has a mass of 8.8 grams. According to $30.00 per kilogram cost, the Swept Tri-Blade costs

$0.26.

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Test Performance for Prototype One

The turbine was ran for a timed interval of three minutes using the testing set up provided

for experimentation and found that the max voltage was 0.2 volts. The turbine was within the

area determined to have the highest air flow and set at the appropriate distance from the air

source (Appendix B). The center of the turbine was at approximately 22.5" tall. This placed the

turbine in what was measured as the optimal position for usage.

The base of the turbine was also tested for stability. This was done by attempting to move

the top of the motor mount and ensuring that it held the motor and would not be affected by

adverse movements as a result of the air flow acting on it. This ensured a constant position of the

propeller and an ample amount of air passing over it as such. The stability test was performed to

ensure that the base of the turbine would be safe and hold up to the effects of the air acting on the

base during usage. This also confirmed that the turbine would be safe for consumer use.

The wind speed test was performed in order to identify the best positioning and placing

of the turbine during testing and to give an exact measurement of the forces of the air acting

upon the blades of the wind turbine. This prevented the turbine from being placed incorrectly and

ensure it was optimally placed and designed to ingest the optimal amount of air.

The voltage test was done to test the effectiveness of the turbine and to see if it would

produce and acceptable output. This test was conducted with the fully assembled prototype to

allow for the most accurate measurement possible.

The motor mount and propeller were weighed to calculate the total mass of each and to

see if there would be the possibility to reduce the weight in the future to allow for a lighter

design of the turbine as a whole. This test showed that the motor mount weighted 37.7 grams and

the blades weighted a total of 13.9 grams. It was determined that the blades could be made both

larger and thinner in order to improve efficiency and reduce weight. The motor holder could also

be lightened by shelling the structure and also making a side of the square tangent to the post to

reduce material used, which would also save on cost.

Using an equation to determine the power of the generator,Watts=Current∗Voltage and

Current= VoltsResistance , it can be determined that the generator produced .00143 watts while the

generator was under 28 ohms of resistance. This shows the need for increased efficiency of the

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blade design and the need for improvement for the generator to produce closer to its two watt

capacity in future prototypes (Appendix A).

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Test Performance for Prototype Two

The second prototype was ran for three minutes and produced a maximum voltage of

0.12 volts. This is dismal when compared to what the turbine can produce, and in comparison to

the first prototypes maximum voltage.

The blade was set at a height of 15" which was determined to be the optimal height so

that the majority of the blade would utilize the maximum wind velocity in that region, which

would be approximately 20" high (Appendix A).

The base was determined to be stable, however, it suffered from extreme vibration,

potentially lowering the power and maximum voltage produced. It was able to withstand the

minimum requirement of not failing for three minutes which is the primary goal of the base

structure.

The wind speed test, the stability test, and the voltage test were performed in order to

make sure that the prototype would meet the requirements determined by the project, and by the

group. While the prototype met these requirements, it performed poorly in the group’s eyes and

has multiple aspects that can be improved upon.

The weight of the second prototype, in comparison to the first, is extremely heavy. It also

produces less power and has a lower maximum voltage which needs to be increased in order for

a prototype to become a viable option that is worthy of production.

This conclusion was reached by performing wind velocity, stability tests, and also

weighing the structure. This enabled the group to find the optimal height for the turbine to

operate and also horizontal positioning. A stability test was conducted by running the trial for a

three minute period and ensure there were no additional stresses on the turbine. The structure

was also weighed to ensure that the structure would not be obscenely heavy, thus potentially

affecting the efficiency, and structural integrity.



generator was under 28 ohms of resistance. This shows the increased efficiency of the blade

design and the need for improvement for the generator to produce closer to its two watt capacity

(Appendix A).

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Test Performance for Prototype Three

The third prototype was ran for three minutes and the maximum voltage produced was

4.01 volts. The voltage was produced at a height of 19.5 inches which was determined to be the

optimal height for this blade design (Appendix B). The turbine was centered in the exact location

where wind speed was determined to be highest. This allowed the blade to utilize the maximum

amount of air and generate the highest voltage possible for this blade design.

The base was also tested for stability by running a full three minute run to ensure the

prototype would be able to meet the minimum requirements. It was found that with the torque

support, the base would enable the shaft to stay straight and thus reduce vibrations that could

cause the blade to be less efficient than predicted. The primarily cardboard base withstood the

test without issue and proved to be durable for the given conditions.

The motor mount weighed a total 0.6 grams which is much lighter than the original motor

mounts. The propeller design was also much lighter than all other designs, weighing only 8.8

grams. The overall weight of the structure became considerably lighter due to a change of

cardboard thickness and other design differences, which enabled the design to only weigh 254.4

grams. This improves the standing for the weight while also increasing the original durability

and power significantly.



generator was under 28 ohms of resistance. This shows the increased efficiency of the blade

design and the improvement for the generator to produce closer to its two watt capacity

(Appendix A). These aspects made turbine three the most efficient and effective option of the

three prototypes tested.

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ConclusionThe first prototype met all of the design criteria specified. The wind turbine produced

energy and withstood the three minute test period. The base also passed all stability tests

allowing for it to be put into production. Given the amount of power that was produced, it is not

recommended that this iteration be used as a final product and is therefore not ready for

consumer use. There are multiple aspects that could be improved upon. One such aspect would

be the blade. The current propeller is not efficient enough for use or further experimentation. It

would be beneficial to increase the surface area of the individual blades, as well as produce the

blades out of a lighter material. Such materials for the blades could include Styrofoam, balsa

wood, or cardboard. Throughout research, it was shown that three long blades were the most

efficient design, however the first prototype did not utilize this to its advantage, though it may

still be worth developing a new propeller design based on this idea. It would also not drastically

affect the cost of the turbine by exploring the route.

The second prototype made many of the changes suggested after analyzing the

performance of the first prototype. The longer blades that were made to be wider created to much

drag for the additional advantage to be used to its full potential. It was also far heavier than the

first prototype which added to the list of disadvantages that the second prototype incurred. While

the turbine passed all requirements, it did not meet the group’s standards. The group focused on

going forward from the second prototype was improving upon the power output, lowering the

weight, and increasing the stability of the base.

The third prototype remedied the majority of grievances that were had with the previous

prototypes. It drastically increased the power output from 0.2 volts to 4.01 volts. This resulted in

a power increase of 500% in comparison to the first prototype. While this could be further

improved, the group feels that this is satisfactory for the given conditions and the possibilities

presented by the current testing protocol. The turbine also weighs less than either prototype

further increasing its favorability with the group. The cost also decreased which improves the

overall cost effectiveness of the turbine. While, the power and weight could be improved, the

group has does not currently have the means to improve upon the third prototype, and while a

gear train or belt system could be added, the group does not believe it will be entirely beneficial

to the turbine.

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BudgetsThe purpose of the budget is to allow the project to be tested with respect to what the total cost of

the prototype would be if it were to be put into production.

Budget for Prototype One

Table 6: Budget for Prototype One

Object Price

Half-Inch Cardboard Sheet 30” X 40” $1.69

¾” PVC Pipe 5' $3.91

Motor Holder ABS Plastic $1.13

Tri-Force Blades ABS Plastic $0.42

*Hot Glue Stick 5/16” X 4”* $1.21

Total $8.36

*Found at (MID Hardware n.d.)*

Budget for Prototype Two

Table 7: Budget for Prototype Two

Component Price

11.75” x 8” x 4.75” Shipping Box $0.62

¾” Schedule 40 PVC Pipe $1.37

Transparent Hot Melt Glue Stick $1.04

Motor Mount $0.27

Motor Attachment $0.63

Total $3.93

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Budget for Prototype Three

Table 8: Budget for Prototype Three

Component Price

11.75” x 8” x 4.75” Shipping Box $0.62

1/2” Schedule 40 PVC Pipe 5 feet $1.26

Transparent Hot Melt Glue Stick $1.04

Tri-Blade ABS Plastic $0.26

Total $3.18

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Mass of TurbineThe purpose of these tables is to note and sum all masses of the prototypes in the measurement of

grams.

Mass of Turbine Prototype One

Table 9: Mass of Turbine One

Object Mass

¾” PVC Pipe – 19.5” length 154.7g

Cardboard 8” x 8” x .5” 22.2g

Motor Holder - ABS Plastic 37.7g

Tri-Force Propeller 13.9g

Motor 56.1g

Total 284.6g

Mass of Turbine Prototype Two

Table 10: Mass of Turbine Two

Object Mass

3/4” Schedule 40 PVC Pipe – 15” length 118.6g

Base of cardboard 87.7g

Water Wheel Blade 98.6g

Motor 56.1g

Total 361.0g

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Mass of Turbine Prototype Three

Table 11: Mass of Turbine Three

Object Mass

1/2” Schedule 40 PVC Pipe – 19” length 129.2g

Cardboard 12” x 12” x 1/8” 48.4g

Support Materials 5.6g

Swept Tri-Blade 8.8g

Generator 56.1g

Torque Support 2.7g

Hot Glue 3.6g

Total 254.4g

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Appendices

Appendix A: Generator Specifications

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Height in Inches33 0 0 0 0 0 0.8 0 1 1 0.8 0 0 0 0 0 0 031 0 0 0 0 0 0.9 1.8 2.8 2.4 1.1 0.3 0 0 0 0 0 029 0 0 0.7 0.8 1 3.7 3.5 5.2 5.5 3.5 1.8 0.8 0 0 0 0 027 0 0 0.9 1.3 2.9 2.3 5.5 8.2 12.8 5.0 5 2.4 1.1 0.9 0 0 025 0 0 1.4 1.4 5.5 4 5.6 12.5 13.7 8 4.2 3.3 2.4 1.4 0.8 0 023 0 0.9 1.6 2.3 6 7.8 14.7 16.9 17.2 11.1 6.4 3.6 2.6 2.1 1.1 0.7 021 0 1.2 1.8 4.3 6.4 8.4 18.7 23.1 19.5 13.5 8.5 4.8 3.1 1.9 1 0.8 019 0 0.8 1.2 2.9 7.3 10.4 19 21 21 12.5 7 2.6 2.1 1.3 0 0 017 0 0 0.9 2.1 5.8 8.5 14 18.6 14 11.2 4.8 2.7 2 1.1 0 0 015 0 0 0 1.4 3.2 6.3 8.5 12.4 9.5 7 4.8 1.5 1.1 0.9 0 0 013 0 0 0 0 1.5 4.9 6.8 7.3 5.7 3.4 3 0.9 0 0 0 0 011 0 0 0 0 0.8 1 2.3 1.8 2.3 0.8 0 0 0 0 0 0 09 0 0 0 0 0 0 1.8 0.8 1 0 0 0 0 0 0 0 07 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 05 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 03 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 01 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33Width in Inches

Appendix B: Measured Wind Speeds

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Works CitedContech Engineered Solutions. n.d. Wind Turbine Foundations. Accessed February 2, 2016.

http://www.conteches.com/Markets/Wind-Turbine-Foundations.

Gurit. n.d. Wind Turbine Blade Structural Engineering. Accessed February 25, 2016. http://www.gurit.com/files/documents/3_blade_structure.pdf.

MID Hardware. n.d. Mintcraft, mini glue sticks for jlgg10. Accessed March 2, 2016. http://midhardware.com/hardware/product_info.php?products_id=6228761&gclid=COC6m5GNpcsCFQyEaQodkY8AcA.

PVC Fittings Online. n.d. 1" Schedule 40 PVC Pipe . Accessed March 1, 2016. http://www.pvcfittingsonline.com/4004-010ab-1-schedule-40-pvc-pipe-5-ft-section.html?gclid=CjwKEAiAmNW2BRDL4KqS3vmqgUESJABiiwDTEueUgrwMlpEPKA4SSUxtxLlttkM1wys4B5EuFFiVCRoCxQzw_wcB.

Utrecht. n.d. Utrecht Corrugated Cardboard 30 x 40 inches. Accessed March 1, 2016. http://www.utrechtart.com/Utrecht-Corrugated-Cardboard-30-x-40-inches-MP-13900-001-i1015872.utrecht?utm_source=google&utm_medium=cse&utm_term=13900-3040&country=US&currency=USD&gclid=CjwKEAiAmNW2BRDL4KqS3vmqgUESJABiiwDT3Wi2VJV4eOJ7gOT8uUQf6Edg6DGw5CWDtzo9.

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Wind Turbine Design Report FINAL