Team10 DDR Final

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Team 10

Ali Alnuaimi, David Manley and Se

Rooney

The Pennsylvania State University

March 29 2013

Cordless Vacuum Detailed Design

Report


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Team 10 Detailed Design Report Page 1 of41 ME340.5

Executive Summary

ACME Tool Company has acquired an outstanding reputation in their tool departmentwith the sales of their cordless drills, saws, and sanders and therefore wishes to expand theirproduct line with the addition of a cordless vacuum. In response to ACMEs desire to expandtheir tool product line to include a cordless handheld vacuum, the following detailed designreport will explain the design process carried out by three mechanical engineers, studying atPennsylvania State University. The final product will provide ACME with the quality productthey desire and maintain their reputation as a reliable customer service company. Benchmarking,

gathering customer needs, and concept generation initially allowed our team to acquire thenecessary consumer information to design the appropriate, yet affordable product that ACMErequires. Net Present Value and environmental effect studies have allowed us to design anaffordable and responsible product. More specifically, the Net Present Analysis shows a profit of$3, 4256,800 after the first five years and additionally shows the company will have paid alloutflow costs and break even during the third quarter of the second year of production. Mostimportantly, keeping the safety of our costumer as being crucial, our sealed chambers completelyenclosed design, ensures the users all around safety.

Designing the product to be made of lightweight and cost effective material will allowACME to outsource their manufacturing and mass produce this product in a cost effectivemanner. As can be seen in the theoretical analysis, this cordless handheld vacuum will producethe necessary pressure drop between the nozzle and fan to allow for high volumetric flow rate,while enabling easy waste removal in the bottom end of the nozzle, through innovativecentrifugal technology and a dual collection chamber. Our design sought out the most energyefficient techniques using friction reducing bearings and backward curving blades to not onlysave the consumer in purchasing cost, but in the cost for power consumption. In addition, the twofilters (one placed before the fan and one after) assure the user of not only a tightly sealedfiltration system which will effectively trap all the debris, but also fan durability by protectingthe blades from being struck by particles, allowing our vacuum design to be one which will lastfor years. This revolutionary concept of a vacuum attachment provides current customers with acost effective yet powerful solution to their cleaning needs, and for those looking into gettingtheir first power tools, our product gives the customer both a cordless drill and a cordlessvacuum at one affordable price. After combining ACMEs needs for an affordable yet desirablenew product for their tool company line with the customers needs for a portable, cordlessvacuum that will clean all types of messes, no one will want to miss out on such a valuableproduct.


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Table of ContentsExecutive Summary ...................................................................................................................................... 11. Introduction ............................................................................................................................................... 3

1.1 Problem Statement .............................................................................................................................. 3

1.2 Background info .................................................................................................................................. 3

1.3 Project Planning .................................................................................................................................. 4

2. Customer Needs and Specifications .......................................................................................................... 42.1 Identification of Customer Needs ....................................................................................................... 4

2.2 Design Specifications .......................................................................................................................... 5

3. Concept Development .............................................................................................................................. 63.1 External Search ................................................................................................................................... 6

3.2 Problem Decomposition ...................................................................................................................... 6

3.3 Concept Generation ............................................................................................................................ 73.4 Concept Combination ......................................................................................................................... 8

3.5 Concept Selection ............................................................................................................................... 8

4. System Level Design ................................................................................................................................ 94.1 Overall Description ............................................................................................................................. 9

4.2 Preliminary Theoretical Analysis...................................................................................................... 10

4.3 Preliminary Economic Analysis........................................................................................................ 11

5. Detailed Design ....................................................................................................................................... 115.1 Modifications to Proposal Sections ................................................................................................... 11

5.2 Final Theoretical Analysis ................................................................................................................ 125.3 Component and material selection process for mass production ...................................................... 13

5.4 Fabrication processes for the mass production unit .......................................................................... 13

5.5 Industrial Design ............................................................................................................................... 14

5.6 Detailed Drawings ............................................................................................................................ 14

5.7 Economic Analysis ........................................................................................................................... 18

5.7.1 Unit Production Cost .................................................................................................................. 18

5.7.2 Business Case Justification ........................................................................................................ 18

5.8 Safety ................................................................................................................................................ 19

6. Testing .................................................................................................................................................... 196.1 Test procedure and plan .................................................................................................................... 19

7. Conclusion .............................................................................................................................................. 208. References ............................................................................................................................................... 21Appendices .................................................................................................................................................. 21

A. Project Management .......................................................................................................................... 21

B. Customer Survey and Reviews........................................................................................................... 22


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C. QFD Matrix ........................................................................................................................................ 25

D. Problem Decomposition ..................................................................................................................... 26

E. Concept Generation ............................................................................................................................ 27

F. Concept Combination ......................................................................................................................... 28

G. Concept Scoring Matrix ..................................................................................................................... 29H. Patents ................................................................................................................................................ 30

I. Dirt Devil Test Results ........................................................................................................................ 33

J. Motor Test Data ................................................................................................................................... 34

K. Battery Test Data ............................................................................................................................... 35

L. Detailed Drawings .............................................................................................................................. 35

M. Bill of Material and Net Present Value ............................................................................................. 39

1. Introduction

1.1 Problem StatementACME has given us the task of designing a cordless handheld vacuum with a target retail

price of $50. The company already has a line of power tools, and we are to design our vacuum sothat it is able to run off the same 18 volt battery and motor platform, which their other powertools are built around. All other parts of the drill are not required to be used in the design of thecordless vacuum. The final prototype (beta) must contain at least one component that has beenfabricated using rapid prototyping, water jet, or CNC processes. Our spending limit on materialsand components is $30. The ultimate goal is to design an economically viable consumer productwhile adhering to the previously mentioned constraints. An economically viable vacuum cleaneris a necessity for many households, with a potential global market for this product.

1.2 Background infoThe main component of any vacuum cleaner on the market is the fan. Many fan types are

used to create pressure drop that is needed to implement the suction mechanism. The stronger thepressure drop the stronger the suction will be. The dissection of various types of handheldvacuum cleaners exposed the team to the different fans used in vacuum cleaners such as axialand centrifugal fans. The completed research has given the team a strong sense of thespecifications and parameters that should be incorporated in our design. By investigating existingpatents, our team is capable of recreating and modifying existing vacuum cleaners to satisfy theguidelines for this project. In addition, our team, with its practical and theoretical knowledge, isdetermined to improve the existing line of handheld vacuum cleaners and identify marketopportunities.

Since the design of the vacuum cleaners deals mainly with fluid flow, we are confidentthat our team will be able to succeed in building a cordless vacuum cleaner due class experience


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in fluid flow analysis. Not only do our team members have practical experience and are certifiedin machining parts, but we also have a solid theoretical background. Our team members havegained valuable knowledge over the years as mechanical engineering students at Penn State.Each member has the required technical background in fluid mechanics, heat transfer, electricalengineering, and machine design. Using this knowledge, the team has been able to study the

design of many handheld vacuum cleaners in the market to identify any weaknesses and seek amarket opportunity. In addition, we have conducted surveys and researched customer reviewsand patents. All of which strengthens our arsenal in building an efficient, practical, and costeffective cordless handheld vacuum cleaner.

1.3 Project PlanningWith such a long and in-depth design process ultimately leading to the actual

manufacturing of our cordless vacuum, our team has created a Gantt chart (Appendix A) to keepthe group on pace and to assign individual tasks. The Gantt chart provides us with due dates offor each step in the process and delineates the task specific group. This process divides theresponsibility within the group as well as keeps the group as a whole on pace to meet each

deadline. The Gantt chart is updated at every group meeting to ensure the team is focused and ontrack with the design process.

2. Customer Needs and Specifications

2.1 Identification of Customer NeedsIn order to determine our customer needs we decided to gather information from various

sources. We used face to face interviews, electronic mail interviews, and consumer responseinformation to gather data for our needs. The quotes of the customers and the interpretation of

their needs can be seen in Appendix B.

As a result of this data we were able to determine the customers major desires and needs.The most important need that we discovered was that the vacuum had to achieve high levels ofsuction. This is extremely crucial because it affects the performance of the vacuum which, as oursurvey results showed, was the most important feature. Next we discovered that a sealedfiltration area was very important. Consumers desired this feature highly because suction ofmaterial is futile if the material cannot be contained properly. The customer needs that wereestablished next in our hierarchy were that of easy waste removal and easy maneuverability. Anozzle needs to be properly designed which allows the vacuum to easily reach waste materialwhich may be located in areas such as hard to reach corners. After the material is suctioned intothe machined and stored in a contained area, it is essential that the waste material is easilyremoved from the vacuum so that it can be disposed of efficiently. If this feature is not designedproperly the waste material could easily be spilled. In order to allow for the execution of all theother processes, the vacuum has to have a battery which is powerful enough to allow for thecleaning of a large area without recharging. For this reason battery life was our next highestneed, however, consumers did not really care how long the battery life was as long as it allowedsufficient time for cleaning. Finally our three lowest customer needs were: reasonable noiselevel, reasonable weight, and acceptable appearance. The customers stated that they would like


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the noise level to be low, the weight to be reasonable, and the appearance to be acceptable;however, they would be willing to sacrifice these criteria for increased suction and the otherpreviously stated primary needs. After full evaluation of our customer input, metrics werecreated through Quality Function Deployment (QFD) as seen in Appendix C. Both the customerneed interpretations and QFD were then ultimately used in the weighting process of our design

specifications.

2.2 Design SpecificationsOnce we collected all our customer input and categorized this data into what we thought

were the ultimate customer needs, the design specifications were made. A total of nine differentdesign specifications were developed. Each design received a specific weight in correspondenceto its stressed importance from our costumer interviews. After evaluating what each customerthought to be important when using a portable cordless vacuum, each design criteria wasweighted so that the total of all the weights summed up to one. Below, Table 1 describes whyeach specification was weighted the way it was, mostly resulting from our customer input. It isobvious to see, as stated above in our customer interpretation, that suction power, waste removal

process, and excellent filtration are the most important factors we need to keep in mind as wemove through the design process. Therefore, Table 1 tells us we must strive for strong suction,an easy waste removal system, and a completely reliable filtration system when continuing onthrough concept selection. Also, we realize from the weighted specifications that noise level,weight, and appearance are the factors we should consider throughout the concept generationprocess. As seen in Appendix G, the weights derived in Table 1 are further used in the conceptselection scoring matrix.

Table 1: Criteria Weighting Table

Criteria Weight Description

High Suction 0.2 Suction power of the cordless vacuum is strong

Sufficient Battery Life 0.1 Battery life is sufficient for the need task

Easy Waste Removal 0.15 Waste removal compartment is simple to use

Reasonable Noise Level 0.05 The cordless vacuum is not annoyingly loud

Reasonable Weight 0.05 The cordless vacuum is light enough to move with ease

Acceptable Appearance 0.05 The cordless vacuum is pleasing to the eye

Easy Maneuverability 0.1 The cordless vacuum can reach corners easily

Sealed Filtration Area 0.2 No waste will penetrate the filter; only air

Durability 0.1 The housing and fan will not break deform easily


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3. Concept Development

3.1 External SearchAfter collecting consumer information and ranking needs for the final vacuum design, we

began to gather information for design concepts. Our patent searches were conducted usingGoogle Patent Search and the United States patent search. The patents of interest found are: ablade for a vehicle engine cooling fan assembly, two types of centrifugal fans, an axial flat fan,three different types of handheld vacuum cleaners, a portable electric vacuum cleaner, and a dustcup. These patents can be found in Appendix H. We also performed benchmarking tasks bygathering technical information on vacuum cleaners which are already in production. These twoexternal searches provided us with many technical specifications, performance goals, and designconcepts which we were able to incorporate into our design.

Table 2: Benchmarking against market leaders

Description Description Description

Dyson DC32 Cordless:2.92lbs; 12x8x4; Lithium-ion battery; cyclonic action;bagless; similar to drillhandle trigger

Retail Price: $127.49

Shark Rotator Cordless: 2-Speed w/ 10 positioningnozzle; 3-stage filtration;Easy-empty system


Eureka The Boss Cordless: 3-3.5V rechargeable power;4x17x6; Clean air systemhelps protect motor; fingertipon/off switch


3.2 Problem Decomposition

In order to break down the vacuum into various systems to be analyzed, our teamdeveloped a black box diagram. The inputs into the system are energy, air and impurities, and asignal to the vacuum. The energy enters the system and is stored in the battery. Next, the triggersends a signal which converts the electrical energy into mechanical energy through the motor.The motor in turn runs the fan which pulls impurities in through the filter. The outputs of thesystem are energy in the form of heat, noise, and vibration, air which had been filtered, and thewaste material collected in the filter. The flow chart of our problem decomposition can be foundin Appendix D.
http://gadgetgrid.gadgetgridllc.netdna-cdn.com/wp-content/uploads/2010/07/Black-Decker-18-Volt-Pivoting-Nose-Cordless-Energy-Star-Handheld-Vacuum-Cleaner.jpghttp://www.shoppingnexus.com/for-the-home/pr/dyson-dc34-cordless-vacuum-cleaner-refurbished.html


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3.3 Concept GenerationThe team conducted an external search to better familiarize ourselves with the current

market of handheld cordless vacuum cleaners. We also looked at several heavy cordless vacuumcleaners in the market to seek ideas that can be implemented in our design using methods of

scaling and similarity.Once the team was familiar with physical principles and the operation of fans, we

brainstormed and identified some unique design concepts. We then generated some task specificproduct ideas and broke them down into sub-systems that consist of the fan, the nozzles, thehousing, and the filter compartment. Sketches can be found in Appendix Section E.

The first set of designs that we sought to generate was pressure difference generatingdevices. These designs consisted of using varying types of fans to create the desired pressuredifference. Two different types of fans could have been applied: axial and centrifugal. An axialfan is the simplest design to construct since air is simply pulled linearly through the fan andstraight out the back. The second type of fan, the centrifugal fan, draws air in through the front ofthe fan and then sends it out at a ninety degree angle after centrifugal force sends the air radially

outward. This type of fan is able to produce a greater pressure per unit volume of air. In thecategory of centrifugal fans that we researched, three different types of blades were found. Thefirst type of centrifugal fan was one with radial blades. This is the simplest design and is mostsuited for low volume and high pressure application. The downside to this design is that itproduces a large amount of noise as compared to its alternatives. The second type of centrifugalfan incorporated forward curving blades. This design is generally used for high flow and lowpressure applications. The final type of centrifugal fan that we generated had backward curvingblades. This design is generally used for high pressure and medium flow applications. Also thisdesign is much more efficient than the other previously mentioned designs. After exploring theoptions of traditional fans to create a pressure difference, we looked into alternative designs. Apneumatic pump is utilized in one of our designs. This pump is driven up and down to create a

pressure difference. The next concept incorporated a pressurized tank and two separate tubes.The air in the tank is rapidly released and flows over the opening of another tube, creating apressure difference, and drawing air through the lower pipe thereby creating suction. Finally wetook the previously generated idea of incorporating two tubes, but used a fan system instead of apressurized tank.

Next, our team considered different nozzle designs. The first design is a tubular design, inwhich the nozzle is the same diameter the whole way along its length. This would be the simplestoption to produce. The second consideration was a rectangular pipe. The pipe would have thesame size opening across the whole length. This would also be simple to produce but may inhibitthe flow of particles due to the corners. The third type of nozzle we generated incorporated aconverging end to the nozzle. This would cover more surface area, creating a strong suction

power. Due to this realization we generated our final design which incorporates a diverging endto the nozzle, ultimately creating the greatest amount of suction per unit area at the end of thenozzle.

After generating concepts for creating a pressure difference, and varying nozzle designs,we generated concepts which approached filter locations in two different ways. Our initiallygenerated idea for the filter was to have it at the outlet of the fan to catch the debris which exitsthe fan. However, after investigating this design we determined that this would allow thecollected debris to hit the fan blades therefore leading to part degradation.


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Finally after discussing all of the performance aspects we decided to analyze differenthousings and cosmetic ideas. Our two basic ideas were to either keep the original drill, or toremove the drill housing and to build a new one to hold the new equipment.

3.4 Concept CombinationAfter creating the various concepts we began our concept combination phase. In thisphase we began by creating four main categories, or tasks, which the vacuum needs toaccomplish. The first category that we chose was suction design. In this category we listed ourconceptual ideas for, an axial fan, a centrifugal fan, a pump, an air tank, and a two tube design(Note these items were previously discussed and sketched). The next category that we selectedwas the dust to vacuum interface. In this section we listed our various designs for nozzles, suchas, a tubular nozzle, a converging nozzle, a diverging nozzle, and a rectangular nozzle. After thiswe established the category of dust collection. In this section we only had two options, pre fan,or post fan. Finally in our last section we discussed appearance. For this we simply had thedecision to keep the drill body, or to create a new housing.

After setting up the combination tables we further selected four concept systems whichwe believed could be possible solutions to the assigned task. For our first design we went withour most simple concept. This design looks as if it is simply a long tube with a handle on theback of it. Starting from the front, the vacuum has a circular nozzle. This nozzle design is simpleto manufacture and leaves a broad path for the collection of particles. The next component in thisdesign is the simple axial fan, which is used to create suction by moving air rapidly, creating apressure difference. Behind the fan is a filter to catch the waste. Our next system of designsfeatures a nozzle with a diverging tip. This tip creates a smaller opening which increases thesuction over a smaller area. Behind this nozzle there is an expanded chamber with a filter at theback. This chamber allows the particles to slow down and drop into the collection area at thebottom of the chamber. A centrifugal fan behind this section allows for an increased air flow rate

of air, as compared to its axial counterpart. We also decided to keep the drill body to lower thecost of production, and to allow for the possibility of a vacuum attachment to the drill whichslips directly into the chuck. Our third design incorporates much of the second design, with onlyminor adjustments. The only difference in this design is that waste is not filtered out before it hitsthe fan, instead the waste, along with the air, is directed out of the vacuum by the fan. In this waythe particles actually hit the fan blade, and the blades assist in pushing the particles into thecollection area adjacent to the blades. Our fourth and final design is once again based off of theoriginal drill body to save money. A circular nozzle is once again being used in this design.However, unlike concept number 1, the waste is filtered out by the vacuum before it hits theaxial fan in the rear.

3.5 Concept SelectionIn order to finalize the concept selection stage and carry on with the process with anultimate design, we created a weight scoring matrix as seen in Appendix G. This matrix used anin depth process of evaluating our final three concepts and ultimately proving one as the bestconcept. The scoring matrix uses the earlier created design specifications and their weights. Inaddition, each of our final three concepts was given a rating of one through five, five being thebest, for each of the nine specifications. Each concept rating of one through five was multipliedwith the previously assigned weights to the specifications and then summed up as seen in the


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matrix. The highest total, which turned out to be our second concept, is the concept we willfollow through with.

Our first concept, a tubular axial fan with post fan filter received a high ranking in weightdue to the fact that this concept would not incorporate the whole drill in its design. However,drill weight was not one of our highly rated specifications. It received low ratings in high suction

due to the axial fan choice over a centrifugal fan, and durability as a result of being filter-lessbefore the waste particles hit the fan. Lacking a filter before the fan, certain particles could chipthe fan blades over time. These low ratings in durability and suction caused this concept to losethe overall competition.

Our second concept, a drill body centrifugal fan with pre-fan filter, was the concept thatultimately won final concept selection. This concept received low ratings in weight andappearance as a result of the actual drill body being a necessary attachment in order for thevacuum to run. However, the centrifugal fan and pre-fan filter placement resulted in high ratingsfor suction and durability, respectively. Since, according to our customer needs interpretations,suction and durability are much more important than weight and appearance, this concept had amuch higher score than concept one.

Concept three was much similar to concept two besides the fact that the filter in conceptthree was placed after the fan, similar to concept one. This filter placement negatively affectedconcept threes rating in durability because of possible fan damage over time as a result of thewaste particles entering the fan system instead of being filtered out beforehand. This lower ratingin durability resulted in concept twos total score being higher.

After the final scores of each of the three concepts, it can be seen that concept two wasthe winner. However, as a group we realized that it is a good idea to have a filter after the fan aswell as before, acting as a backup filter. Ultimately, we decided on a combination of concept twoand three, including both a pre-fan and post-fan filter, as our final concept.

4. System Level Design

4.1 Overall DescriptionAfter weighing the features of our four design combinations, the results were clear that

concept number two was the most viable option for several reasons. To begin, with the lowbudget that our team has been given, while still being tasked with integrating this product intothe current line, the most cost efficient option was to use the current drill body. Using the currentbody also gives us the option of making the vacuum a drill attachment, which would cut costseven further and completely integrate our design with their existing products. For the nozzledesign we selected the diverging nozzle tip, with either a rectangular or oval shaped tip. Thisdesign gave us the largest width for the cleaning path, while still creating a small enoughopening to increase suction. This design will also aid in reaching into corners that you would beunable to do with a traditional circular tip due to the larger radius. After the nozzle, the tubeopens up into a larger chamber. This design helps aid in the collection of waste by slowing downthe particles and allowing them to be more easily filtered out by the filter at the rear, and also todrop into the collection area at the bottom of the chamber. Finally we selected the centrifugal fandesign. After researching this design and that of the axial fan, we discovered that the centrifugalfan is able to achieve higher levels of suction than that of the axial fan. As a final feature weadded a second filter at the exit of centrifugal fan with a finer filter which is able to catch


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material which may have made it through the first filter. This helps to contain the maximumpossible amount of material. An exploded view of our preliminary concept design can be seenbelow in Figure 1.

4.2 Preliminary Theoretical AnalysisOur team tested the Dirt Devil cordless vacuum cleaner presented in class, and decided to

utilize fans affinity laws to perform preliminary analysis.One of the laws states that,

()

Where, subscript 1 refers to our fan & 2 refers to the Dirt Devil vacuum cleaners fan From our test we obtained, Assuming our fans diameter and our motors most efficient speed ,

() ()

So, by having a larger radius fan blade, we can make up for decrease in the volumetric

flow rate caused by the slower rotational speed of the motor. In order to get a better

understanding, other factors must be taken into account such as number of blades, angles ofblades, duct size, etc. All of which will be included as we get into our detailed design phase.

Figure 1: Exploded view of our concept design for the handheld vacuum cleaner


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4.3 Preliminary Economic Analysis

Table 3: Economic Analysis for our handheld cordless vacuum cleaner

BILL OF MATERIALS

Component Process Unit Cost after Mass Production

Fan Blade Injection molding $2Fan Housing Injection molding $2

Two filters Buy from vendor $0.50

Nozzle/body/housing Plastic mold $5

Fan/Drill connection piece Buy from vendor $3

Motor ACME $4

Battery ACME $5

TOTAL $22

GRAND TOTAL (@ 100,000 vacuums/yr) $2,200,000

Labor: Assume 5 workers assembling drills at minimum wage at $7.25/hour @ approximately 40 hours aweek for 52 weeks. This will be the labor cost for one year;

5 workers*$7.25/hr*40hrs/wk*52wks/yr = $75,400

Drills at retail price = $50/unit*100,000(units sold in 1 year) = $5,000,000.00

Profit = $5,000,0000 - $2,200,000 - $75,400 = $2,724,600/yr

5. Detailed Design

5.1 Modifications to Proposal SectionsThe team has performed slight modifications to the proposal as constructive feedback has

been received in addition to the experience and knowledge gained by working on the projectfurther ever since. The following modifications have been made:

The concept generation section has been modified to incorporate more details onthe process, which have not been explained in sufficient details in the proposal.This should serve to clear confusion and provide a better flow of information tothe reader.

The Theoretical Analysis section has been expanded and more detailedcalculations have been made to incorporate dimensions of fan and volumetricflow rate (See section 5.2 below).

The Economic Analysis section has been expanded as well to incorporate theBusiness Case Justification.

The Gant Chart that plans the teams schedule has been modified to accommodatethe changed schedules of team members (See Appendix A).


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5.2 Final Theoretical AnalysisIn this section the performance of the fan is analyzed theoretically. In order to obtain an

approximate value for the volumetric flow rate, the dimensions of the fan and housing have to bedetermined first. By using Fan Affinity laws, the team was able to scale the dimensions relativeto the Dirt Devil Cordless Vacuum cleaner tested in class. The following calculations were

made:For Dirt Devil (DD), Based on our drill testing, Using Affinity Law to determine the diameter of the fan,

( )

Using the same diameter ratio as the Dirt Devil, Using the following expression for the volumetric flow rate, the dimensions of the outlet of thefan can be determined: Where,

And, Where, Width of the outflow area becomes,

( )

Area of out flow area is, With this analysis, we the team has obtained approximate dimensions for the fan and an expectedperformance of the fan with the motor chosen. As the team begins the building process, given itsiterative nature, these numbers might change accordingly.


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5.3 Component and material selection process for mass productionAs a result of our vacuum acting as an attachment to our drill, it will contain fewer

components, most of which can be injection molded. Keep in mind however, that if the user doesnot own a cordless drill, it will need to be purchased separately in order for the fan attachment tobe inserted into a chuck. Furthermore, our team has chosen to use Acrylonitrile Butadiene

Styrene (ABM) as the main material. This material is a common thermoplastic that isinexpensive but is tough and impact resistant. The fan, nozzle, veneer, front housing, backhousing, and waste collection compartment will all be manufactured with this ABMthermoplastic by injection molding (explained below). Since thermoplastics are easily recycled,our ABM plastic will also be environmentally friendly. Aside from material choice, the otheraspects of our products life cycle were also considered. For example, simple manufacturingsteps result in less byproduct produced by the factories. As a result, our team approached theproject with a simple but efficient design. Also, with respect to distribution, we strove to makethe smallest design as possible therefore allowing more units to be shipped in one transportationprocess. Other materials, such as our filters, steel ball bearing, epoxy and screws will need to bebought already manufactured. Buying these components will raise the costs of them slightly, but

we believe that since they are minor components in the design, avoiding additionalmanufacturing costs would be beneficial. Lastly, since the battery and motor will already be apart of the drill our vacuum attaches to, they are not a worry in our component selection process.

DFE Assessment

Factor

Cordless Vacuum

Score

Factor

Weight

Weighted

Score

Material Chemistry 40% 33.3% 13.32%

Recycled Content 10% 8.4% 0.84%

Disassembly 85% 33.3% 28.31%

Recyclability 80% 25% 20%

Overall Score 100% 62.47%

5.4 Fabrication processes for the mass production unitInjection molding was our choice of manufacturing for mass production for a couple of

reasons. First off, this type of manufacturing is ideal for high volumes of the same object andfurthermore the most common modern method. Since our mass production will reach over ahundred-thousand products a year, our team believes injection molding is the correct choice. Theplant will be in Singapore, where the fan, nozzle, veneer, front housing, back housing, and wastecollection compartment will all be injection molded with the ABM thermoplastic. Once the partsare molded, this process will move to an assembly line that has been designed to be not onlyefficient but also environmentally friendly. Sixteen technicians and three engineers will bepresent at the plant. The technicians will assemble the parts together with provided tools, whilethe engineers will overlook the processes. Since the filters, bearing, and screws will bepurchased in bulk outside of the plant, they are not a concern when considering the fabricationprocess but will be shipped to the plant for assembly after being purchased.

Table 4: Design for Environment Weighted Table


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5.5 Industrial DesignThe aesthetics of our design fit our target audience, ACME power tool users. The teams

goal is to achieve the best ratio of aesthetics, efficiency and durability. The ACME consumersare likely to purchase a portable vacuum cleaner that looks like a power tool which the team asaccomplished by incorporating the drill body. In addition, the red and black colors chosen

demonstrate the industrial feel that satisfies the ACME power tools line.Ergonomics is the study of designing equipment and devices that fit the human body, itsmovements, and its cognitive abilities. From an ergonomic standpoint, the vacuum cleaner willhave the ability to adjust to different angles, easy battery replacement location, lightweight, andthe ability to reach tight spots for cleaning. Furthermore, the handle of the drill used in thevacuum cleaner design increases the portability and ergonomics. Also the centrifugal fan is easyto disassemble because of the use of screws and rods.

5.6 Detailed DrawingsIsometric View:

Exploded View:


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Back Plate:

Bearing:

Our fan attachment system utilizes a solid back plate forour housing. This plate will be created using plasticinjection molding. This allows us to manufacture the part atextremely low costs; it also allows us to maintain alightweight yet strong structure. The bearing will be

mounted in the hole in the back of the housing.

A bearing, which will be mounted in the back plate, will givethe fan the ability to rotate freely in the housing. A closed,steel ball bearing will be used to provide a sturdy interface,while creating a minimum amount of friction, allowing thefan to rotate without losing a significant amount of energy to

friction.


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Fan:

Housing Body:

Front Plate:

Our design incorporates a centrifugal fan with backward-curved blades. Backward-curved blades are the mostefficient style of blades, and are used for high powerapplications. A model will be created using a 3D printer.From this a mold will be made, and in production the fan

will be created using a plastic injection molding process.

The Body of our housing is made from by injection

molding. This allows us to easily create this complexcurve in a cost effective manner. Creating a solid plastic

piece also allows for an increase in strength.


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Collection Chamber:

Nozzle:

NOTE:

For the detailed drawing for each of the parts which will be used for the production specifications pleasesee appendix section L.

This part is located at the front of our housing assembly.It is used to enclose the fan, and to create anotherstructural feature to maintain rigidity. This part will be

made using plastic injection molding.

The next part in the assembly is the collection chamber. Aprimary filter is placed on the hole of the front plate. Thesand and other debri will hit this filter and fall down intothe long slit at the front of the chamber (1). After the fan,air exits in through the extruded hole (2), and then througha second filter located on the end of the part (3). In this wayall of the debri is collected in one location. This chamber isdetachable from the vacuum for easy waste disposal. This

part will be manufactured using plastic injection molding.

3

2

The final piece in our vacuum assembly is the nozzle. Thispart utilizes a nozzle with a reducing radius to create asmaller opening diameter, increasing the localized suction.

This part will be created through plastic injection molding.


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5.7 Economic AnalysisThe economic analysis in this report is one of the most important sections because it will

tell the designers if the product is economical. More importantly, it will tell the potentialinvestors how much how profit is to be expected if they invest in the proposed design. Aquarterly analysis over the first five years based on the calculated unit price can be found in

Appendix L.

5.7.1 Unit Production Cost

The unit production cost began with an updated bill of materials. This BOMincluded every part needed to assemble the vacuum attachment. Since the idea of our designteam is to have our vacuum act as an attachment to drill, the user must also purchase the drill if itis not owned yet. Together, the bill of materials came out to be reasonably close to the assumedprice of $30.00 per unit. Without the drill included in the unit price, the bill of materials is verycheap. This is because the customer would only be purchasing an attachment, which would notinclude the battery or motor needed to operate the vacuum.

As can be seen in the BOM, the injection molding manufacturing process of the fan,housing, waste compartment, and nozzle will all have an individual material, tooling, andproduction cost that all sum up to a unit a price. These will be manufactured at the plant inSingapore by the technicians and engineers. These prices were all calculated on an online sitewith an assumed production rate of 100,000 units. Along with the assumed 100,000 units, thecalculation took into account that the material is ABM thermoplastic, the area and volume ofeach individual part, and the precision to which the part should be made. As a result, we believethese unit prices are very accurate.

On the other hand, there is no material, production, and tooling costs associated with thescrews, bearing, and filters. This is due to the fact that the plant will not be manufacturing thesecomponents but instead buying them from other vendors. Therefore, only a single unit price hasbeen provided in the bill of materials.

The last cost taken into account was the labor costs. Assuming it takes a

technician twenty minutes to assemble a vacuum; then on an 8 hour workday 24 drills could beassembled by one technician. Also figuring out that at a pace of 100,000 drills per year, 385drills would need to be assembled per day. This led to a total of 16 technicians with their salaryof $10,000 a year provided to us. Lastly, it was assumed efficient to provide the plant with 3engineers as well to overlook the processes. These previously mentioned salaries result in a laborunit cost of $1.60 for technicians and $0.90 for engineers. As previously mentioned, adding thelabor costs to the unit cost in the BOM in Appendix M along with the cost of the drill results in avery similar unit price of the assumed $30.00 which was used for our Net Present Value analysisin the following section. The specifics of the previous labor cost calculations can also be foundin Appendix M.

5.7.2 Business Case Justification

After calculating the period cash flow by quarters over the first five years, it wasfound that our product would create a Net Present Value of $3,425,680 at a ten percent discountrate. However, the outflows to get production started would not be subsided until the thirdquarter of year two. The outflows, including development costs, ramp-up costs, and marketingcosts are all variables that can be altered depending on the companies needs and wants.


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However, salaries must be considered in ramp-up costs when production has started but theramp-up process has not yet been completed.

Since the company was expected to make 50,000 products the first year, a lot ofconsideration was given to balancing out production and startup. Our team decided the first twoquarters to solely have outflows with no inflows in order to build the factory and start the ramp-

up process. The third quarter would then start production with a quarter of the needed units whilethe fourth quarter producing the rest of the 50,000 units. At this time, the marketing outflow costwould also start up because this cost normally goes hand-in-hand with production. After the firstyear, the company would produce 25,000 units a quarter to meet the quota of 100,000 units peryear for the next four years. This production would result in $350,000 per quarter before thediscount rate is applied. This can be seen in the NPV table in Appendix M.

Lastly, our NPV table in Appendix M also shows the results when the product would beat discount rate of 15%. With this discount, a profitable NPV would still be the result:$2,895,170. It can also be noted the company would still break even in the same quarter as the10% discount rate.

5.8 SafetyThe safety standards will be done after the beta prototype has been tested and shown to

work. This additional safety review will be done after acceptance of the final report by aconsultant yet to be hired.

6. Testing

6.1 Test procedure and planTesting is critical to the success of any design project. The purpose of testing our

prototype is to understand how the vacuum cleaner is going to operate under various conditionsand allow the team to detect any unexpected phenomena. In addition, data obtained fromdifferent types of testing can provide the team with information regarding the expectedperformance with respect to the performance of the Dirt Devil under the same conditions. Thiscould result in possible modifications in our design if needed.

The team has developed a testing plan that will test the vacuum cleaners air flow, noiselevel and battery life under the same conditions that the Dirt Devil has been tested on. The DirtDevil test involved measurements of Air Flow using an anemometer and noise levelmeasurements using the Extech Sound Level meter at various distances. The team seeks toperform the same tests on the prototype of the vacuum cleaner to better understand how thedesign compares to the Dirt Devil. The setup and results of each test done on the Dirt Devil can

be seen in Appendix I.

The following is the test plan to be performed once the prototype has been built:

Air Flow:o Air flow will be measured by using an anemometer 2 inches from the inlet

of the fan. We expect our fan to produce an air flow of ,which is the value obtained from the Dirt Devil test.


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Noise Level:o Noise level will be measured by using the Extech Sound Level Meter 10,

20, and 30 inches away from the center of the fan. We expect our fan to be

within the range of

, which is the range obtained from the Dirt

Devil Test.

Furthermore, two tests were performed on the motor and battery of the drill. Drill motordata was measured using a dynamometer to give the team a basic understanding of the torqueoutput of the motor in the given drill. This data was used in order to find the most optimal motor

speed for the production model, determined to be . The motor test data can be seen inAppendix J. The Battery Life test was conducted in class using the specialized PC providedwhich generated the battery life curves needed. The battery can be operatedfor 21 minutes at aconstant current of 2.6 Amps. The generated curve can be seen in Appendix K.

7. ConclusionOur team was tasked with developing an economically viable vacuum which can be

efficiently incorporated into a companys current line of products. In our short period of work onthis product, we began our task by identifying customer needs through various types ofsurveying methods. After compiling the survey data, we then conducted additional researchthrough patent searches, benchmarking, and internal concept generation. Combining theseconcepts, we identified four designs which would satisfy the concept requests for our product.Using our determined customer needs hierarchy, we were able to determine the most viabledesign option. Our product is fully designed to specific dimensions on a 3D CAD software, someperformance testing has been done, a complete theoretical analysis including all performancenumbers have been calculated, and a Net Present Value analysis has been calculated to prove ourdesign is economically profitable. Specifically, in the third quarter of the second year ofproduction, our design will begin bringing in profits for the buyer of our cordless vacuum. Also,since our profit from our NPV analysis is so high, the buyer could also decide to put more moneyinto development costs, ramp up costs, and especially marketing if decided.

Our handheld vacuum design is especially unique due to its optional attachment style,which allows it to be incorporated into any cordless drill platform. This allows our resources tobe allocated towards increased suction which rivals that of more expensive vacuums, while stillentering the market at the lower end of the price spectrum. This design, due to its unique nature,and extremely low cost of production, is marketable to nearly every household in search of aninexpensive alternative with ample suction. Our team has worked rapidly and efficiently in orderto develop this economically viable product, which is ready to be prototyped for testing.


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8. References

Ulrich, Karl T., and Steven D. Eppinger.Product Design and Development. Boston: McGraw-Hill HigherEducation, 2008. Print.

engel, unus A., and ohn M. Cimbala.Fluid Mechanics Fundamentals and Applications. Boston:McGraw-Hill Higher Education, 2010. Print.

http://www.shoppingnexus.com/for-the-home/pr/dyson-dc34-cordless-vacuum-cleaner-refurbished.html

http://www.gadgetgrid.com/2010/07/27/black-decker-18-volt-pivoting-nose-cordless-energy-star-handheld-vacuum-cleaner/

http://www.ebay.com/itm/Eureka-Boss-Cordless-Rechargeable-Handheld-Vacuum-Cleaner-79B-/330733528197?pt=US_Vacuum&hash=item4d01412485

http://en.wikipedia.org/wiki/Centrifugal_fan

Appendices

A. Project Management

Team RolesDavidRole: Scribe and SpeakerQualifications: Organization, Leadership, and Attention to Detail

SeanRole: Team LeaderQualifications: Leadership, Computer Skills

AliRole: Time Keeper and PusherQualifications: Logical

These are the overall roles of our team. However each team member is the group leader for thetask he is responsible for according to our Gantt chart below.
http://www.shoppingnexus.com/for-the-home/pr/dyson-dc34-cordless-vacuum-cleaner-refurbished.htmlhttp://www.shoppingnexus.com/for-the-home/pr/dyson-dc34-cordless-vacuum-cleaner-refurbished.htmlhttp://www.gadgetgrid.com/2010/07/27/black-decker-18-volt-pivoting-nose-cordless-energy-star-handheld-vacuum-cleaner/http://www.gadgetgrid.com/2010/07/27/black-decker-18-volt-pivoting-nose-cordless-energy-star-handheld-vacuum-cleaner/http://www.gadgetgrid.com/2010/07/27/black-decker-18-volt-pivoting-nose-cordless-energy-star-handheld-vacuum-cleaner/http://www.ebay.com/itm/Eureka-Boss-Cordless-Rechargeable-Handheld-Vacuum-Cleaner-79B-/330733528197?pt=US_Vacuum&hash=item4d01412485http://www.ebay.com/itm/Eureka-Boss-Cordless-Rechargeable-Handheld-Vacuum-Cleaner-79B-/330733528197?pt=US_Vacuum&hash=item4d01412485http://www.ebay.com/itm/Eureka-Boss-Cordless-Rechargeable-Handheld-Vacuum-Cleaner-79B-/330733528197?pt=US_Vacuum&hash=item4d01412485http://www.ebay.com/itm/Eureka-Boss-Cordless-Rechargeable-Handheld-Vacuum-Cleaner-79B-/330733528197?pt=US_Vacuum&hash=item4d01412485http://www.ebay.com/itm/Eureka-Boss-Cordless-Rechargeable-Handheld-Vacuum-Cleaner-79B-/330733528197?pt=US_Vacuum&hash=item4d01412485http://www.gadgetgrid.com/2010/07/27/black-decker-18-volt-pivoting-nose-cordless-energy-star-handheld-vacuum-cleaner/http://www.gadgetgrid.com/2010/07/27/black-decker-18-volt-pivoting-nose-cordless-energy-star-handheld-vacuum-cleaner/http://www.shoppingnexus.com/for-the-home/pr/dyson-dc34-cordless-vacuum-cleaner-refurbished.html


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Gantt chart

B. Customer Survey and Reviews

Face to Face Interviews

Question Statement Interpretation

CUSTOMER 1

(1) What do you think is anacceptable price for acordless handheld vacuum?

I would pay up to $75 The cordless vacuum(CV) can be bought forunder $75.

(2) How long would you

expect the battery life to be ina cordless vacuum until nextrecharge?

I would expect to get 1-2 hours until

next recharge.

The CV has good

battery life.


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(3) How light would youexpect a cordless vacuum tobe?

Weight is not important to me; but Iguess less than 7 lbs.

The CV weight has noeffect.

(4) Any aesthetic preferencesthat would better your

chances of buying a cordlessvacuum?

I like bag-less vacuums; easy turnability; attachment for corners; and

good suction power.

-The CV has bag-lessdisposal

-The CV turns easily-The CV has availableattachments.-The CV has goodsuction.

CUSTOMER 2

(1) I would pay $50 The (CV) can be boughtfor under $50.

(2) I would expect to get 2 weeks ofdaily use until next recharge.

The CV has exceptionalbattery life.

(3) Less than 5 lbs. The CV is light.

(4) I would like a light on the front, andthat it is easy to empty.

-The CV has easy wasteremoval compartment.-The CV has lightsource on front.

CUSTOMER 3

(1) I would pay $50 The (CV) can be boughtfor under $50.

(2) 15 minutes would be an acceptablebattery life.

The CV battery lasts 15minutes.

(3) I would want the CV to be around 3-5 lbs.

The CV is light.

(4) I would definitely want a goodfiltration system, battery life tocomplete task, good suction powerand that it is easy to empty.

-The CV containssealed filtration system.-The CV has suitablebattery life.-The CV has goodsuction.-The CV has easy wasteremoval compartment.

CUSTOMER 4

(1) I would pay up to $100 The (CV) can be boughtfor under $50.

(2) 2 weeks of battery life. The CV has exceptionalbattery life.

(3) Between 3-8 lbs would be a goodweight.

The CV is light.

(4) I would like a shoulder strap andgood suction.

-The CV includes ashoulder strap.-The CV has goodsuction.


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Email Interviews

Question Quote Interpretation

Price Id pay around $65 Price does not matter

Weight Since you have to carry it Id want it to be prettylight

Lighter weight preferred

Wastecollection I always prefer bags, it helps with allergies Sealed waste collection area

Noise level Noise does not really matter Noise level not important

color The color does not make a difference to me Color is unimportant

Key feature Most important is suction, and can it take acharge

Suction is crucial, battery lifeimportant

Price I would only pay $40 Needs to be economicallyviable

Weight I go to the gym I dont care how heavy it is Weight is not important

Wastecollection

I dont want to have to worry about a bag aslong as the dirt cant get out

Sealed waste collection area

Noise level It cannot be extremely loud Noise level fairly importantKey feature It must suck really well Suction crucial

Price I would pay up to $75 Price does not matter

weight I would want it to be light, like 5 lbs Lightweight

Wastecollection

For a handheld I would want bagless if it stillcollected the waste well

Efficient and complete wasteremoval

Noise level I dont care how loud it is as long as it has highsuction

Noise level is unimportant

Key feature Lots of suction Suction is crucial

Online reviews

Criteria Quotes InterpretationPrice I dont mind paying an extra 20-30$

for qualityQuality of vacuum is moreimportant than price

Weight I wouldnt want to carry a heavyvacuum even if its the best in its class

Weight is crucial

Battery life Excellent suction but unfortunatelyvery short battery life

Battery life is crucial

Key FeaturesDesired

Wish it was easier to empty the dustcup

Easy waste removal is desired

Noise Level Powerful and light vacuum but soundslike a jet engine!

Low noise is desired


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C. QFD Matrix

Metrics

1 2 3 4 5 6 7 8 9 10

11

VolumetricFlowRate=275

(ft^3/min)

LifeofBattery=15(mins)

Detachable/Appearance

NoiseRange=50-80(dB)

WeightLessthan8(lbs)

Sleek

NozzleShape

NozzleSize

FilterShape

FilterPlacement

WasteStorage

Needs

1 High Suction X

2 Sufficient Battery Life X

3 Easy Waste Removal X

4 Reasonable Noise Level X

5 Reasonable Weight X

6 Acceptable Appearance X

7 Easy Maneuverability X X

8 Sealed Filtration System X X X


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D. Problem Decomposition

Cordless VacuumCleaner

Figure 2: Black box of vacuum cleaner

Input

Energy

Air/Impurities

Signal

Output

Energy (Heat, Noise,Vibration)

Collected Impurities

Battery Motor

Fan BladesFilter Filter

On/OffSignal

Cleaning

Input

Energy

r/Impurities

Signal

Outpu

Energy (Noise&Vibrat

Air

Waste

Figure 3: Functional Decomposition


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E. Concept Generation

General idea: This sketch represents the ultimategoal we are trying to achieve for our prototype.Using the drill housing, the fan will be attachedto the chuck along with the filter.

Different suction mechanisms: This sketchrepresents the types of fans and suction

mechanism that we investigated.

Different Nozzles: This sketch represents thedifferent shapes of nozzles that we investigated.

Filter location and Housing: This sketchrepresents the locations of dust filter and theshape of the housing.


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F. Concept Combination

Suction Mechanism Dust to vacuum interface Dust Collection Appearance

Axial Fan

Centrifugal Fan

Pump

Air Tank

2-Tube Design

Tubular Nozzle

ConvergingNozzle

DivergingNozzle

RectangularNozzle

Pre- Fan

Post - Fan

Drill Body

NewHousing


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G. Concept Scoring MatrixConcepts

(1) Tubular Axial

Fan with Post Fan

Filter

(2) Drill Body

Centrifugal Fan

with Pre-Fan Filter

(3) Drill Body

Centrifugal Fan

with Post-Fan Filter

Selection Criteria Weight Rating WeightedScore Rating WeightedScore Rating WeightedScore

High Suction 0.2 1 0.2 4 0.8 4 0.8

Sufficient BatteryLife

0.1 3 0.3 3 0.3 3 0.3

Easy WasteRemoval

0.15 3 0.45 3 0.45 2 0.3

Reasonable NoiseLevel

0.05 3 0.15 3 0.15 3 0.15

Reasonable Weight 0.05 4 0.2 2 0.1 2 0.1

AcceptableAppearance

0.05 3 0.15 2 0.1 2 0.1

EasyManeuverability

0.1 2 0.2 3 0.3 3 0.3

Sealed FiltrationArea

0.2 2 0.4 3 0.6 3 0.6

Durability 0.1 2 0.2 4 0.4 2 0.2

TotalScore

2.25 3.2 2.85

Rank 3 1 2

Continue?

No YesNo, but combine back

filter with Concept(2)


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H. Patents


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Distance

2 inches

Dirt Devil Vacuum Anemometer

Figure I.1: Schematic of the test setup

Table I.1: Measured and calculated data for Dirt Devil Air Flow Test

Dirt Devil VacuumSound Level

Meter

Figure I.2: Schematic of the test setup

Table I.2: Measured and calculated data for Dirt Devil Noise Level Test

I. Dirt Devil Test Results

Air Flow

Noise Level

Make and Model: Dirt Devil GatorTM

Test Date: 03/01/2013

Measured Data

Distance (in) Rotation Speed (rpm) Volumetric Flow Rate (ft3/min)

2 1030 250

Make and Model: Dirt Devil GatorTM

Test Date: 03/25/2013

Measured Data

Distance (in) Noise Level (dB)

10 75.6

20 71.2

30 67.9


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Power Supply Voltmeter/Ammeter Drill Dynamometer

Tachometer

Control Tool

Figure J.1: Schematic of the setup

J. Motor Test Data

Drill Make and Model: Black & Decker 2009-21-58-11 Test Date: 02/13/2013

Measured Data Calculated Data

Speed (RPM)Load Torque

(oz-in)

Input

Voltage

(Volts)

Input

Current

(Amps)

Electrical

Power

(Watts)

Load

HP

Mechanical

Power

Output

(Watts)

%

Efficiency

1002.00 0.00 119.40 1.68 200.59 0.27 0.00 0.001111.00 25.00 119.60 1.64 196.14 0.26 20.54 0.10

1088.00 50.00 119.40 1.72 205.37 0.28 40.23 0.20

1044.00 80.00 119.10 1.93 229.86 0.31 61.76 0.27

971.00 110.00 117.60 2.05 241.08 0.32 78.98 0.33

889.10 170.00 118.50 2.54 300.99 0.40 111.77 0.37

Table J.1: Measured and calculated data for Black & Decker 2009-21-58-11 Drill dynamometer test conducted on 02/13/2013

Figure J.2: Plot of various parameters vs Load Torque (oz-in) for the Black & Decker 2009-21-

58-11 Drill d namometer test

Figure J.3: Plot of various parameters vs Load Torque (oz-in) for the Black & Decker 2009-21-

58-11 Drill dynamometer test


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K. Battery Test Data

L. Detailed Drawings


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M. Bill of Material and Net Present Value

Figure M1: Complete Bill of Materials


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Labor Cost Evaluation:

-Assumption made the drill assembly takes technician approximately 20 minute.

-This shows our plant will need to manufacture 385 drills every workday in order to meet the100,000 quota. Then, at 20 minutes to make a drill, 1 worker can make 24 drills in one day. Basedoff of these two calculations:

= 16 technicians at the plant-Then, we assumed 3 engineers to oversee the processes would be sufficient.

-Then at salaries of $10,000 and $30,000 for the technicians and engineers respectively:

Technician

Engineer

***NOTE: In the following NPV analysis, we chose to use the assumed

production cost of $30 dollars per drill because our previous BOM does not

include the drill due to the fact we are making it an attachment part.***

The Net Present Value in the following table was found with the formula:

Where ris the discount rate and n is the total number of payment period i.


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Documents

Team10 DDR Final