Aqua Ball Progress Report 3December 2014

Provided by:

STAJTech Signature Date

Tyler Vondahaar

Shiv Panigrahi

Abhishek Dhar

Jianyi Du

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Table of Contents

Executive Summary.......................................................................................................................iii

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

2 Problem Scoping......................................................................................................................1

2.1 Problem Background.........................................................................................................1

2.2 Target Customers..............................................................................................................2

2.3 Marketplace.......................................................................................................................3

2.4 Benchmarks.......................................................................................................................4

2.5 Problem Definition............................................................................................................6

3 “Aqua Ball” Design.................................................................................................................6

4 Bill of Materials.....................................................................................................................10

4.1 Cost Analysis..................................................................................................................10

4.2 Manufacturing Processes................................................................................................10

4.3 Material Selection...........................................................................................................11

5 Analysis of Design.................................................................................................................12

5.1 Performance Analysis.....................................................................................................12

5.1.1 Slope Pushing Model...............................................................................................12

5.1.2 Friction Model.........................................................................................................14

5.2 Assembly Analysis..........................................................................................................16

5.3 Economic Analysis.........................................................................................................17

6 Conclusion and Recommendations........................................................................................17

References......................................................................................................................................19

Appendix A: Final Assembly for Aqua Ball.................................................................................20

Appendix B: Slope Pushing Model Plots......................................................................................21

Appendix C: Friction Model..........................................................................................................23

Appendix D: Financial Analysis of STAJTech’s Aqua Ball Design.............................................25

Appendix E: House of Quality......................................................................................................26

Appendix F: Bill of Materials........................................................................................................27

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Executive Summary

STAJTech’s goal with this project is to develop a cheap, portable and safe water transportation solution for third world countries that allows women and children to transport water more efficiently. Contained in the following are the research results, final design details, design validation and performance, final bill of materials, engineering modeling, comparison to benchmarks, and conclusion. The object of this report is to clearly show STAJTech’s Aqua Ball design with detailed drawings and descriptions, demonstrated by research results and design validation.

STAJTech focused on the problem faced by people in third world countries. In these areas, there is no convenient access to clean water, and people are forced to travel long distances and spend hours to get enough water from natural sources for the entire family. This responsibility most often is delegated to women and children, who could be spending time earning money for the family or working on an education. The customers for this product include those direct users and charitable organizations. This product will be sold to charitable organizations, who in turn will provide the device to people in need. Both of the target customers have a focus on price, because if the solution is too expensive, then it will not be feasible to use. However, the direct users care more about the performance of the product, including durability, weight, water capacity, terrain capacity, and ease of use.

Two benchmarks are selected for STAJTech’s product, namely HippoRoller and the Wello Water Project. These benchmarks provide a baseline that a new product can be compared to as well as a reasonable target price of $100.

The Aqua Ball design stands out with two innovative features, namely a spherical design to enhance the maneuverability and a braking system. Aqua Ball has a simple structure of three main parts and two working modes for pushing and pulling, respectively. Simple manufacturing processes confined to rolling, milling and drilling are adopted for one or two parts, and the materials chosen are UV Stabilized Linear Low Density Polyethylene, steel and rubber. The cost of product is calculated to be $27.97, hence the retailing price would be $111.88, which surpasses 10% of the target price. However, considering the innovative features, this price is still reasonable. Also, the costs can be further reduced in mass production with possibily cheaper materials.

Performance analysis shows that the capacity of Aqua Ball is balanced between family needs and users’ strength at 60L, and the braking system works fine in case of emergency. Therefore, Aqua Ball’s two innovations are proved to be feasible. Aqua Ball has eight assembly processes. Design for Assembly is used to help improve the assembly processes and the results are evaluated from 68 pts to 74 pts with a fullmark of 104 pts, which means that the assembly processes are proper to implement.

STAJTech’s Aqua Ball design shows its innovations in many aspects, including spherical structure, braking system, to name a few. Together with its simple structure and profitability of $32,600 of net present value after 15 quarters, Aqua Ball is capable of solving the problem STAJTech addresses and can be put into market in mass production for profits.

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1 Introduction

The purpose of this report is to present STAJTech’s water transport device. Detailed research, design, evaluation and analysis processes are included.

STAJTech focused on a critical problem in the third world which is the lack of easy and safe water transportation from natural sources. To address this problem, STAJTech started off with research and came up with several concepts with different techniques. After due evaluation, the final concept was selected. Detailed designs including drawings, assembly and manufacturing processes followed. In addition, STAJTech analyzed the final design in aspects such as performance, assembly and costs. Lastly, a prototype was made to show the structures and functions of the final concept.

This report is divided into six sections. Section 1 introduces the purpose and the structure of the report, as well as accomplished work by STAJTech. Section 2 presents the problem STAJTech faced with corresponding customer and market research, along with benchmarks and the problem definition. Section 3 focuses on the details of STAJTech’s final design named Aqua Ball, including operation descriptions and drawings. Section 4 presents the final bill of materials for the concept, detailed with cost analysis, manufacturing processes and material selection. Section 5 analyzes and presents the final performance, assembly and economic analysis. Section 6 concludes the report and gives recommendations for future work.

2 Problem Scoping

2.1 Problem Background

Clean water is the indispensable resource for the survival of human beings, yet it is still inaccessible in many parts of the world, especially in rural areas of developing regions like Africa, Asia, Latin America, and the Caribbean. As can be seen from Figure 1, approximately 10% of the world lacks access to clean water. This translates to about 780 million people, or one in nine people, that confront this clean water crisis on a daily basis [3].

Fig. 1 - Percent of World Population That Lacks Clean Water

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People that lack access to clean drinking water

People that have access to clean drinking water

Because of the lack of basic infrastructure in these areas, the only available water sources for these people are local rivers and streams. These water sources are often far from where they live. Additionally, water weighs a lot for a single person to transport, especially for women and children, who are more likely to take such responsibility [1]. In fact, carrying water to meet daily needs takes a huge amount of time. Among undeveloped regions of the world such as Bangladesh, Kenya, and Ethiopia, people spend as many as 200 million hours per day collecting and transporting water for their communities [1].

There is another major effect of unsanitary water beyond health and physical burden: lack of education. As stated before, children are enlisted to obtain water once they are of age. This has one very negative result, that those children spend their time getting water instead of going to school. According to statistics, approximately 443 million school days per year around the world are lost due to children ailing from water related diseases [3].

To address this water transporting problem, STAJTech aims at designing a solution that helps a single person, especially women and children, with easy, efficient and safe water transportation.

2.2 Target Customers

There are two main customers of STAJTech’s product.

The first one is the direct users of the product. To be more specific, they are the individuals in the third world communities that do not have access to clean water. Currently they use primitive tools to address this problem, as shown in figure 2. They need a durable solution that allows them to transport enough clean drinking water for their families for an entire day.

Fig. 2 - Women Carrying Water via Buckets

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The other target customers are the charitable organizations that support individuals in third world countries to afford such products. The reason to set these target customers is because the target end users are residents of rural third world areas, and it was realized that they will not be able to directly afford any sort of device. Therefore, those organizations provide the device to the affected people.

With the help of the House of Quality shown in Appendix E, STAJTech finalized the customers’ requirements. The most important requirements for the end users of our design are: durability, weight, water capacity, terrain capacity, and ease of use. This device needs to be durable enough to last at least 7 years in the field in addition to being be as easy to use as possible. It also needs to carry enough water for an entire family. For the charitable organizations, the most important requirement is price. The charitable organizations need a functioning device, but if the price of the solution is high it will not matter if it is the superior solution because it won’t feasible to produce. Fulfilling all of these requirements will lead to an extremely effective device with a price point that will allow it to be mass produced and sent around the world.

2.3 Marketplace

The target markets for this product are third world countries that have a large population that lack access to clean drinking water. Figure 3 shows that this market includes countries like India, Nigeria, Ethiopia, and Indonesia. There is a strong correlation between lack of clean drinking water and overall wealth. Statistics show that most of the target countries have a GDP of less than 500 billion. Because of this, the end users would prefer to purchase a product with a lower price. In addition to that, STAJTech’s target customers will also include charitable organizations like Water.org that are already working to provide aid in these target markets.

Our price target will be less than $100 to be comparable with existing solutions. Also, it is within the affordable limit of common charitable organizations for mass production. Our solution will cut down on the time it takes to collect water by increasing the transport capacity of one person. Our solution will allow these people to spend more time on earning income for their families, especially women, as well as getting children back to school for better education.

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Fig. 3 - Countries without Clean Drinking Water [1]

2.4 Benchmarks

The first benchmark product is the HippoRoller [4], shown in Figure 4. This device has won multiple design awards for its simplistic, functional design. This device is a 24 gallon water barrel that has a detachable handle. The handle allows the user to turn the device upright, fill it with water, and return it to a horizontal position and push or pull the barrel along. This puts all of the weight of water on the ground, and requires far less effort to move large amounts of water. This device is made of thick plastic, and the company claims that it will last 5-7 years without any need for maintenance. Although this device allows the user to carry large amounts of water, it does not have any built in filtration capabilities. The website says that the user can purchase a separate lid that includes a filter, but this comes at an extra cost. This device can be purchased for $143 and shipped worldwide to a country in need for an extra cost. This product is mainly focused in Africa, and has been implemented in small numbers over the past 15 years.

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Fig. 4 - Hippo Roller Water Transportation Device [4]

The second competitor product is called the Wello, by an organization called the Wello Water Project [5]. This device is essentially exactly the same as the HippoRoller with some minor aesthetic changes and a 25 gallon capacity as seen in Figure 5. This project has a smaller focus however, and only aims to introduce its product in India. The reason for this focused approach is it allows the project to keep its costs low. The Wello water roller is priced around $30, which makes it far cheaper than the HippoRoller. This nonprofit organization recently received a round of funding after a successful pilot program in 2011 and a redesign of their product. The Wello Water Project aims to increase production to expand to more communities throughout India.

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Fig. 5 - Wello Water Transportation Device [5]

2.5 Problem Definition

Among undeveloped regions of the world such as Bangladesh, Kenya, and Ethiopia, people spend 200 million hours per day collecting and transporting water for their communities [1]. Because of the lack of basic infrastructure in these areas, the only available water sources are local rivers and streams. These sources are often polluted, which contributes to spread of disease resulting in the deaths of 3.4 million people per year[1]. Our goal is to design a solution that allows a single person to easily transport water to and from water sources as well as ensure that the water is safe to drink.

Our target customers are the charitable organizations that support individuals in third world communities as well as the individuals in these communities that do not have access to clean drinking water. These people need a durable solution that allows them to transport enough clean drinking water for their families for an entire day. Currently, there are solutions called the HippoRoller and Wello Water Roller that provide a way to transport water, but have potential issues with durability and do not filter the water. From an engineering perspective, these devices also have issues with stability and safety due to the lack of braking systems and adequate steering devices. Our price target will be less than $100 to be comparable with existing solutions. Our solution will cut down on the time it takes to collect water by increasing the transport capacity of one person. Our solution will allow these people to spend more time on earning income for their families, and prevent the spread of diseases, which take the lives of millions each year.

3 “Aqua Ball” Design

As the final solution to STAJTech’s problem, the concept is structured as a spherical water tank connected with a handle, and a rotatable braking pad is hinged on the handle ends to provide two working modes. Figure 6 shows the whole product. All the parts are introduced in the following paragraphs. They are shown individually in figure 7.

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Fig. 6 – Aqua ball CAD screenshot (“Pushing” mode)

The water tank in figure 7(a) is a hollow sphere with a hole on the surface. Water flows in and out from this hole. The rubber cap in figure 7(b) is inserted into the hole to seal the sphere. Another two holes are made to install the shafts connecting the handle with bearings, shown as white parts in figure 7(a). At the end of the handle, shown in figure 7(c), two slots allow the shaft/bearing assembly to slide up and down within the slot. When the user pulls up on the handle, the shaft/bearing assembly will move to the bottom of the slot, allowing the vessel to come into contact with the brake pad. The braking pad is shown in figure 7(d). This pad has two rubber pads that use friction to slow down the rotation of the water vessel when they come in contact.

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(a) (b)

(c) (d)

Fig. 7 – Aqua ball CAD parts (a) Water tank; (b) Rubber cap; (c) Handle; (d) Braking pad

According to STAJTech’s customer research above, women and children with less strength usually take the responsibility of carrying water. When they lose control of the heavy device, they can be severely hurt. Therefore, emergency braking is important. There are two working modes of STAJTech product, with different positions of the braking pad. When it stands on the handle, users can only push the device forwards. Therefore, the water tank goes to the back end of the slot without touching the braking pad. This mode is shown in figure 8(a). When the handle is pulled for braking, the water tank keeps moving to the other end of the slots due to inertia. At this time, the water tank surface touches the braking pad, and friction slows down the rotation, as shown in figure 8(b). Hence the movement of water tank can be timely stopped.

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(a) (b)

Fig. 8 – Aqua ball CAD screenshot (“Pushing” mode) (a) Device is pushed forward; (b) Device is pulled for braking

The other mode is for pulling, when the braking pad is lifted up. Figure 9 illustrates this mode. In this mode, reversely, the water tank goes to the front end, and similarly, when it is pushed for braking, the water tank goes forwards by inertia. Then the tank surface touches the braking pad to slow down.

Fig. 9 – Aqua ball CAD screenshot(“Pulling” mode)

The braking pad is connected to the handle with hinge joint, for it doesn’t hinder the free rotation. As shown in figure 10, the hinge joint is put on the slots of the handle, but with some space to the ends. Therefore, pivots are not directly on the pad, rather, the which is then less likely to break.

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Brake pad in contact with tank surface

Fig. 10 – Hinge joint between handle and braking pad (red circled)

4 Bill of Materials

As shown in Appendix F, STAJTech’s bill of materials presents the costs, manufacturing processes and material selection of the Aqua Ball design. They are detailed in the following chapters.

4.1 Cost Analysis

According STAJTech’s bill of materials, total cost of the Aqua Ball design is $27.97, and the retail price would be $111.88. The costs can be divided into three parts, namely, purchased parts of $6.74, custom manufactured parts of $15.73 and assembly costs of $5.50. For the retailing price, though it surpasses 10% of the target price, it can still stand out in the marketplace with the features of good maneuverability and braking system. In addition, the costs can be further reduced in mass production with negotiatable material costs.

4.2 Manufacturing Processes

There are three manufacturing parts for STAJTech’s Aqua Ball design, namely, the spherical water tank, the handle and the braking pad. Due to the complication of the handle shape, it is divided into three individual manufacturing parts and they are sub-assembled before the final one. It is shown in STAJTech’s bill of materials.

For the spherical water tank, it is manufactured firstly by blow molding. There is a metal mold with the shape of the sphere, the polyethylene platic material is placed into the mold, and expanded using heated and compressed air to match the mold shape. After that, when the sphere

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is cooled down, is it taken out. At the end of this manufacturing process, a hole is drilled is on the plastic surface of the sphere to fit the cap.

For the handle, three hollow steel rods are cut according to the drawing for the handle bar, the main shaft and the supporting bar. The supporting bar is further manufactured with rolling, compressing and milling. To be more specific, the supporting bar is firstly rolled on a pipe roller to match the curvature of the spherical water tank. Then both ends of the handle are compressed to plain surface for processing. Finally both surfaces are milled for slots to fit the bearings connected with the spheres. After all three individual parts are manufactured, they are sub-assembled to form the handle, as shown in figure 7(c).

For the last part of braking pad, is is processed with a purchased square steel bar. This bar is cut to fit the shape with coutours at both ends, and then is rolled as the same processes as for the handle supporting bar. At last, two rubber pads are glued to the braking frame. They touch the surface when the sphere is braked, and slow down the rotation. This can be shown in figure 11.

Fig. 11 – Rubber pads on the braking frame(red circled)

4.3 Material Selection

According to the engineering specifications of STAJTech’s product, material for every parts are listed as follows.

The water tank uses UV stabilized linear low density polyethylene plastic, for its light weight, elevate strength and ductility.

The handle and braking pad frame use steel for high strength.

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Rubber is adopted for parts of braking pad which touch the water tank surface, the cap on the water tank and the handle grips. Rubber can provide good friction, hence it can help slow down the device, seal the water tank and enhance maneuverability.

Other purchased parts’ material selections accord to their model numbers and types.

5 Analysis of Design

5.1 Performance Analysis

Two main models for STAJTech’s Aqua Ball are shown in the following chapters to validate the performance. Namely, the slope pushing model shows how the capacity and the structure of Aqua Ball are well designed to get a balance between the needs and the weight, and the friction model shows how the braking system can stop the spherical water tank timely.

5.1.1 Slope Pushing Model

This model focuses on the force users need to apply on the Aqua Ball on the slope with a constant velocity. Different conditions were changed, including the angles of the slope, the angle of the force and the weight of the carried water. The purpose of this model is to validate that capacity is reasonable. STAJTech established the range of possible capacity values with lower limit of 50L, which corresponds to STAJTech’s benchmarks. Then, STAJTech analyzed the various capacities and the resulting forces and masses, and concluded that 60L is appropriate for female and children users.

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Fig. 12 – Free Body Diagram for Slope Pushing Model

Figure 12 shows the free body diagram of this model. Pushing force Fd is exerted through the handle to the center of the sphere, and it has the same direction of the handle due to its ridigity. The sphere is rotating without sliding, so two types of frictions are applied on the surface, namely, static friction and rolling friction, showns as F friciton and M rolling(as moment). Under the condition of constant velocity, all the forces are in equilibrium.

The final equation can be shown as:

Fd=

bR

(M+m )gcosθ+(M+m )g sinθ

cos (θd+θ )− bR

sin (θd+θ )

With Fd sin (θd+θ )+ (M+m) gcosθ

R≤μ.

Where Fd is the applied force on Aqua Ball. M ,m are the cart and water masses, respectively. θd is the angle between the force and the horizontal line, and θ is the slope angle. b is the rolling friction coefficient and μ is the static friction coefficient.

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Detailed plots are shown in the Appendix B with the change of different variables mentioned above. And the results are listed as follows. First of all, when the water tank is fully filled, users need to apply a force of 200-500N to keep the movement. This force range, according to the data, is within the range of the capability for normal people, who can apply 480-600N under common circumstances. In addition, the force direction θd doesn’t affect much on the applied force, which means different heighted users can all easily push this product.

As mentioned before, the slope-pushing model helps STAJTech decide the capacity of the water tank with 60L. It is a good balance between the family needs and users’ strength, especially for women and children, which are the mostly affected users according to the customers’ requirements.

5.1.2 Friction Model

The purpose of this model is to determine the amount of force required to stop the rolling drum in the Aqua Ball at various speeds and stopping distances. The drum is filled with 60L of water, which is equal to 60 kg of mass. This model helps STAJTech determine the effectiveness of the braking mechanism and whether it provides enough force to adequately aid the user in stopping the device. The conclusions drawn from this model show the current effectiveness of the braking system and allow STAJTech to recommend improvements for the future.

Below is a free body diagram of the engineering model:

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Fig. 13 – Free Body Diagram for Friction Model

The free body diagram above shows all forces acting upon the rolling water drum while it is in the braking mode. First, normal force (N) and force of gravity (Fg) are constant while the braking force is applied. The force of rolling friction (Frf) is calculated by multiplying the normal force by the coefficient of rolling friction (Crr). The braking force (Fb) is shown applied perpendicular to the face of the sphere. This braking force comes from the contact between the braking arm and the sphere surface. This braking force varies depending on the required stopping distance and linear velocity. The force of braking friction is calculated by multiplying the braking force by the coefficient of friction (μ). These forces are used to calculate the work done by friction. This work is then equated to the kinetic energy of the sphere, which is then used to calculate the required braking force for any combination of velocity and stopping distance. These equations are shown below.

Equations are shown as follows.

Moment of Intertia : I=25mr2

Kinetic Energy :KE=12I ω2+ 1

2mv2

Force of Rolling Friction :F rf=mgC rr

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Force of Br akingFriction :Fbf=Fb μ

Work doneby Friction :W=(Fbf+Frf )d

Final Equation :Fb=

7mv2

10 d−mgC rr

μ

To evaluate the braking force required to stop the rolling drum, two test cases were devised. In the first case, the velocity is set to be a constant 1.4m/s, which is the average walking speed of a normal person. In this case, the stopping distance (d) is varied to show the relationship between stopping distance and braking force. In the second test case, the stopping distance is set to be a constant 3 meters. In this case, the velocity is varied to show varying walking speeds for different individuals. This test case shows the relationship between velocity and braking force required to stop the rolling drum.

From the data shown in Appendix C, it can be determined that the braking force required for most cases is within reasonable values according to the NASA human force capabilities standard [8]. Arm force abilities depending on shoulder height range from ~ 500-1200 N. Some of the data points for very short stopping distances fall beyond this range, but these are emergency situations and a human should be able to use more muscle groups like legs to create a stopping force greater than 2000N. From this data, STAJTech determined that the braking system is adequate and will allow the user to brake the device with reasonable speeds and stopping distances.

5.2 Assembly Analysis

The assembly drawing is shown in Appendix. It is worth noting that there are three detailed views showing the structures of bearing, hinge and cap connections, respectively. The assembly processes can be shown in figure 14 as a flowchart.

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Fig. 14 – Flowchart of Aqua Ball’s assembly processes

The assembly processes show the improvements indicated in the DFA worksheets.

STAJTech members discussed the design for assembly using the DFA worksheet. Two trials were made, and the team discussion resulted in improvements in the braking system structure as well as and the assembly procedures. Trial one yielded 68/104, and trial two yielded 76/104.

As shown in the first design for assembly, there are some problems in the assembly processes. First, there is no base part for locating surfaces and holes. In addition, repositioning is required for some processes. For better assembly performance, several improvements are made as follows.

To address the base part problem, the sphere is clamped at the beginning of the assembly as base part. Others parts will put on the sphere for convenience. In addition, several manufacturing processes are rearranged. For the example, the sphere is manufactured first. Therefore, it can be easily aligned with other parts. At last, chamfers are designed on some complicating parts, including the braking pad and the handle. To stress the problem of repositioning, some key parts will be assembled ahead of time, including the hinge, the braking pad, the cap, and the sphere

5.3 Economic Analysis

As shown in section 4, the cost of Aqua Ball design is $27.97, which leads to a retailing price of $111.88 more than $100. On the one hand, this price is still competitive among STAJTech’s competitors, for Aqua Ball’s extraordinary innovations including the spherical design and

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Clamp spherical tank as base

Attach shafts and bearings

Assemble hinges on the handle

Attach handle on spherical tank

Assemble braking pad on stablized handle

Add handle grips Unclamp sphercial tank

Final checking

braking pad in case of emergency highlight the whole product. In addition, the simple structure makes the product easy to maintain and handle.

On the other, the costs can be further reduced in mass production with negotiable material costs or alternative materials. For example, the sphere tank uses linear low desnity polyethylene plastic, which takes more than $5 of the total cost, and this material can be substituted by other suitable polymers.

According to STAJTech’s financial analysis shown in Appendix D, the Aqua Ball design with an annual sales of 20,000 has the return on investment of 9.206% per year. STAJTech’s Aqua Ball design will break even in 12 quarters, and will make a profit of $32,600 with in 15 quarters. The price was kept as low as possible to be able to sell to more users.

5.4 Comparison to Benchmarks

The datum chosen by STAJTech for benchmark comparison is the Wello Water Project (shortened as Wello) for its high functionality. Its target users and market overlap to some degree with STAJTech’s. The Wello, as described above, is sold exclusively in India. This device has already gone through a successful pilot program as well as multiple revisions. Currently, the Wello is working on mass producing their water roller and distributing to people that need it in India.

Comparison to this benchmark focuses on features, manufacturing efficiency, and profitability.

First of all, both products well address the basic needs for water carrying, while Aqua Ball performs better in the maneuverability and safety. On one hand, the spherical tank design in Aqua Ball makes it easier to turn directions, and it especially appeals to women and children with much more convenience. The Wello, however, is usually hard to turn directions with cylindrical tank. On the other hand, Aqua Ball design has exclusive safety design, namely the handle end design as well as the braking pad. At the end of the handle, the sphere is stabilized with bearings and shafts, and hence it won’t easily be dropped off the handle. Also, the braking pad can help users stop the device in case of emergency, and it can be lifted up to switch to the other working mode. For Wello, the handle is just inserted into the holes on the sides of the tank, as shown in figure 5, and once it is dropped off on the slope, it will be extremely dangerous and may hit people down the hill.

What’s more, for the manufacturing efficiency, both Aqua Ball and Wello have a simple set of processes. Aqua Ball has more parts, but they can all be manufactured with similar simple methods. Wello has only a few parts, but the cylindrical water tank may take some time to shape for its irregular side and surfaces with texture.

At last, the Wello has a price with only $20-30. This price is much lower than Aqua Ball’s $110. However, considering the fact that the Wello is mainly manufactured in India, where the manufacturing cost is much lower than in the United States, Aqua Ball’s price is still reasonable.

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Furthermore, as mentioned above, improvements in maneuverability and safety for Aqua Ball design offsets the price disadvantage to some degree. In addition, the material costs can still be decreased with further negotiation.

Therefore, the Aqua Ball design meets the requirements shown in STAJTech’s benchmarks. With more features and a slightly higher price, Aqua Ball is regarded as an improved version of a water transport device with a reasonable price, compared with current existing products. The Aqua Ball is fully competitive in STAJTech’s target markets.

6 Conclusion and Recommendations

In this report, STAJTech presents the Aqua Ball design to address the problem met with third world people. Those people don’t have convenient access to clean water. Rather, they have to travel far distance to fetch water from natural sources for the entire day. Women and children are often left with the responsibility of collecting water, making a simple, elegant solution necessary. STAJTech designed a simple water transport device with spherical tank and emergency braking system. It can hold enough water and can be easily maneuvered due to the spherical geometry. In addition, it provides safety for women and children, who take the responsibility of carrying water more often.

Starting with problem background, customer and market research, this report gives details of the final design named Aqua Ball, including operational descriptions, drawings, bill of materials and design analysis. The design has many innovations. Spherical water tank, for example, enhances the maneuverability of the device. And the braking pad helps users, especially women and children, to stop the water tank rapidly in case of emergency. STAJTech’ analysis in performance and costs shows that this product is capable of working functionally and making profits. According to STAJTech’s prototyping, Aqua Ball has met the requirements of mass production.

In the future, Aqua Ball design can still be further revised. First, the structure can be optimized, especially for the braking pad. Currently the braking pad is designed primarily for the “pushing” mode and may not have the same properties as the “pulling” mode. In the future, this could be redesigned to improve upon the “pulling” mode. In addition, improvements can be made to the manufacturing processes according to differrent material selections to save costs and time.

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References

1. UNICEF and World Health Organization. Progress on Drinking Water and Sanitation(Update

2012). 2012. http://www.unicef.org/media/files/JMPreport2012.pdf

2. M. Sundaravadivel and S. Vigneswaran, Rural Water Supply Systems. Wastewater Recycle,

Reuse, and Reclamation, Vol. II. http://www.eolss.net/Sample-Chapters/C07/E2-14-03-

03.pdf

3. Water.org. “Water Facts”. 2014.

4. HippoRoller. http://www.hipporoller.org

5. Wello Water Project. http://wellowater.org

6. Water contaminants. water.epa.gov

7. World Bank http://www.worldbank.org

8. Man system integration standards, “Human Performance capabilities”, NASA,

20http://msis.jsc.nasa.gov/sections/section04.htm

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Appendix A: Final Assembly for Aqua Ball

STAJTech’s final assembly shows all the parts in Aqua Ball design with their assembly relationships.

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Appendix B: Slope Pushing Model Plots

Plots for the slope pushing model are shown below, with changing slope of 5°, 10° and 15°.

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Appendix C: Friction Model

Plots for the friction model are shown below, with difference stopping distances and velocities.

0.1

0.4

0.7 1

1.3

1.6

1.9

2.2

2.5

2.8

3.1

3.4

3.7 4

4.3

4.6

4.9

0

500

1000

1500

2000

2500

Braking Force vs. Stopping Distance (v = 1.4 m/s)

Stopping Distance (meters)

Bra

kin

g F

orc

e (N

)

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0.1

0.4

0.7 1

1.3

1.6

1.9

2.2

2.5

2.8

3.1

3.4

3.7 4

4.3

4.6

4.9

-200

0

200

400

600

800

1000

Braking Force vs. Velocity (d = 3m)

Velocity (meters/sec)

Bra

kin

g F

orc

e (N

)

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Appendix D: Financial Analysis of STAJTech’s Aqua Ball Design

STAJTech’s financial analysis helps decide the profitability of Aqua Ball design.

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Appendix E: House of Quality

STAJTech’s House of Quality helps with evaluation of customers’ requirements.

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Appendix F: Bill of Materials

STAJTech’s bill of material gives the information about the costs, manufacturing processes and material selection.

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