Handheld Vacuum Cleaner

12/10/2015

Team MSM

Max Levy Sultan Alnajdi Yuanye Yang

Executive Summary:

The design goals are to produce a safe, comfortable and powerful handheld vacuum in the $70 price range. Each team member interviewed their family, friends and strangers to identify eight existing and latent customer needs for a handheld vacuum cleaner. Through this research, it was discovered that customers would prefer a handheld vacuum that was attractive, quiet, lightweight, comfortable, safe, easy to maintain, powerful, and had a long battery life. Approximately 50 concepts were generated for various components of the vacuum.These various concepts were compared utilizing the analytic hierarchical process and decision matrices.

After selecting these concepts, five fan prototypes were produced along with a cardboard housing to test the feasibility of the design with an alpha prototype. Once the team validated the basic functioning of the vacuum, a complete vacuum casing was modeled and rapid prototyped.

This beta prototype was then used to extensively test each of the fans based on suction ability. After one round of testing, the five fans were narrowed to three designs and their ability to clean up rice was tested. In addition, various intake configurations were examined and a nozzle was selected to be used.

With the dimensions of the vacuum finalized, a theoretical scaling analysis was performed to compare the flow speed and the gradient pressure loss in the vacuum to further prove the product’s functional capability. Following this, an industrial design which features an underhand carry handle, a push button toggle switch, a removable bag filter, and an easily detachable battery was developed and manufactured into a final prototype for competitive testing in class. The design was validated when it outperformed many other designs in this competition.

Additionally, a net projected value (NPV) analysis was performed utilizing quotes on prices of injection molds and all necessary equipment and parts to produce the product, estimated development costs and times and a fixed production of 100,000 units per year with an annual discount rate of 10%. This analysis showed that over the course of four years, with development included, a net value profit of 5.8 million dollars is possible.

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Table of Contents: 1. Introduction……………………………………………………...page 4-5

1.1 Problem Statement………………………………………………….page 4 1.2 Background Information…………………………………………….page 4 1.3 Project Planning……………………………………………………..page 4

2. Customer Needs and Specifications………………………...page 5

2.1 Identification of Customer Needs…………………………………..page 5 2.2 Design Specifications………………………………………………..page 5

3. Concept Development………………………………………….page 5-8

3.1 External Search………………………………………………………page 5 3.2 Problem Decomposition……………………………………………..page 6 3.3 Concept Generation………………………………………………….page 7 3.4 Concept Selection……………………………………………………page 8

4. System Level Design…………………………………………...page 8-9

4.1 Overall Description…………………………………………………..page 8 4.2 Preliminary Theoretical Analysis…………………………………...page 9

5. Detailed Design…………………………………………………..page 9-14 5.1 Modifications to Proposal…………………………………………....page 10

5.2 Final Theoretical Analysis……………………………………..…….page 11 5.3 Component and material…………………………………………….page 12 5.4 Fabrication processes………………………...……………………..page 12

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5.5 Industrial Design……………………………………………………...page 13 5.6 Detailed Drawings…………………………………………………….page 13 5.7 Economic Analysis……………………………...…….……..……….page 13 5.8 Safety…………………………………………………………………..page 14 5.9 Prototype Manufacturing Process……………...…………………...page 14

6. Testing……………………………………………………………..page 15

6.1 Testing Goal…………………………………………………………..page 15 6.2 Testing Procedure…………………………………………………....page 15 6.3 Testing Results……………………………………………………….page 16

7. Conclusion and Recommendations…………………………..page 16 8. References………………………………………………………...page 18 9. Appendices………………………………………...……………..page 19-31

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1. Introduction

1.1 Problem Statement: The goal is to design a handheld vacuum cleaner that is an economically viable

consumer product. The vacuum will be portable and have compatibility with the existing tool platform. Performance will be gauged on cleaning up uncooked rice that is poured on the table quickly and easily. The main customers of this product will be homeowners and cleaning service enterprises. The motivation behind this project came from the desire of winning the rice competition against the other teams. [Reference 1] 1.2 Background Information:

The vacuum must be compiled from a 18V cordless drill, using various components.The Design must operate with the same NiCd battery pack from the cordless drill, the same battery pack connector and the same DC electric motor. The design may use the same operation switch and modify the function of the switch. Manufacturing will consist of three main prototypes (alpha, two betas) and each will be adjusted to optimize efficiency and operation. The final prototype must contain one component that has been designed by utilizing modified prototyping, water jet, CNC or casting methods.

The budget of this project will be limited of $30 to pay for all the materials and components that will be used for the vacuum. [Reference 2] 1.3 Project Planning:

The project planning initially started by creating a plan to evaluate and discuss our design limits, available sources and tasking responsibilities towards each member. By sharing and discussing these desires, the team compiled these results into the main customer needs. Thus, the process was to relate the customer needs to the engineering specifications through the quality function deployment (QFD) chart available in Appendix B. By comparing each customer need relative to the others, weighted values of each customer need were created. This table is available in Appendix C. The next step was to conduct both external and internal searches to generate concept ideas. During the process, 20 different patents and design concepts were gathered.

The next step was conducting an internal search, by breaking the mental barrier and brainstorming ideas, discussing possible analogies, and improving pre-existing designs the team generated about 50 potential concepts. By recording all of the ideas with self-adhesive postcards and organizing them based on different classes and categories (e.g. Fan, Filters, ergonomics and electric features), the group started creating the concepts for the fan specifically, because it was an important component in the vacuum cleaner available in Appendix D. By examining the dissection and testing of

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the drill, and identifying the components, the early ideas will be modified and a clear image of the vacuum cleaner will be provided

There are several risks that are taken into consideration while the project is being developed. A main risk is that the project could fail during the final delivery, each team member will contribute equally through developing the project in time and on schedule as well as remind other team members of their duty by referring to the team contract [Reference 3]. Another risk is that the vacuum would not operate during the final competition. As such, each team member will be able to analyze the situation and repair or replace any major component that is the cause of the vacuum’s failure. In addition, replacements of the main components will be manufactured to minimize this risk.

2. Customer Needs and Specifications

2.1 Identification of Customer Needs: A diagram of the customer needs and how they relate to the design

specifications is displayed in Appendix B. Customer needs were identified through numerous sources such as gathering information by interviewing family, friends and strangers, utilizing methods outlined in “Product Design and Development” by Karl T. Ulrich and Steven D. Eppinger [Reference 4], and by utilizing internet search for handheld vacuum reviews.

Fundamental customer needs are for the vacuum to be attractive, quiet, lightweight, comfortable, safe, easy to maintain, powerful, and for the vacuum to have a long battery life. 2.2 Design Specifications:

As a team, the product specifications were agreed upon to use a DC electric motor for optimal speed, use a NiCd battery, utilizing a fan design that would maximize the flow of volume per time, the casting material would have a specific weight, an internal damping material to cancel out the motor noise and the design of the vacuum to extract the filters easily.

3. Concept Development

3.1 External Search:

To understand existing ideas and models of handheld vacuums, existing patents were searched and about 20 relatable patents were found. Several concepts within these patents pertaining to safety, airflow, and user experience were discovered.

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Concerning safety, a mechanism that would only allow the vacuum to turn on if the filter was properly attached [Reference 5] prevented injuring the user or releasing dust into the environment. There were also several patents related to the fluid mechanics of the vacuum. These included an automotive turbo charger fan design [Reference 6] and an airflow that created a cyclone to assist in filtering particles from the exhaust [Reference 7].

Lastly, there were numerous concepts that were related to customer experience: an external control to adjust the power of the vacuum [Reference 8], a system of lasers and lights that both illuminated the surface to be vacuumed and alerted the user to the amount of dust on this surface [Reference 9], and orienting the exhaust of the fan so as not to disturb the surface to be vacuumed or blow air on the user [Reference 10].

Current products on the market that team members researched have a slightly angled inlet, and offer the user flexibility in how they can use the vacuum with a variety of nozzles or a rotating/extending inlet head. Also, they commonly weigh less than 6 pounds and range in price from $20 to $250 [Reference 11]. 3.2 Problem Decomposition:

The handheld vacuum can be broken down into four major components acting alongside the user. The decomposition of the vacuum system is shown below in Figure 1.

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3.3 Concept Generation:

Approximately 50 concepts were generated using group brainstorming across several sessions. This allowed the team members to respond creatively to others’ ideas, as well as think independently about the needs and possible solutions of the problem.

These concepts included a flexible hose that could extend and contract to be stored at the inlet of the vacuum, shown in Figure 2. This would allow the user to vacuum in hard to reach areas where the body of the vacuum is too large to fit. It would also not be a burden when not in use since it can be retracted easily. It was also suggested to use a pressure sensitive switch located on the grip of the vacuum, shown in figure 3. Whenever the user holds the handle and squeezes sufficiently, the vacuum will engage. By requiring active application of pressure, the switch ensures that the vacuum can not be accidentally turned on by bumping the switch and guarantees that if the user drops or sets the device down it will automatically turn off. In addition, a safety feature that would break the motor circuit if the filter was not securely attached, shown in Figure 4 was proposed. If the filter is not attached and the fan is engaged, it could be potentially hazardous. Therefore, the filter element will contain a wire or contact pattern so that when it is not in place, the motor’s circuit can not be completed. A concept pertaining to fan design was created that would utilize a long ducted fan, shown in Figure 5. By having a lengthy fan, work could be done on a greater volume of air at a single time, compared to the conventional centrifugal fan. This concept also implied a long tubular body for the vacuum.

Another proposed fan design which aimed to replicate an automobile turbocharger impeller is shown in Figure 6. The key features of this fan model are a conic base shape, as well as multiplanar blades. This concept will allow for a higher torque output to the fluid in the airflow.

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3.4 Concept Selection: Selecting which concepts work was carried out by combining multiple concepts

into three basic models of the vacuum. The first model, dubbed the Turbo Vacuum, contained the turbo fan in Figure 6, as well as a short, circular housing, filter engagement safety shutoff, and an folded breathable paper air filter. The second model, called the Twin Fan Supercharger featured dual fans connected by pulleys and a belt to the motor, a straight, long housing that belled out at the back, and a simple flat paper filter. Lastly, there was a Linear Long Vacuum model, which utilized the long fan in Figure 5, a straight tube-like body, the pressure sensitive switch, and a reusable cloth filter.

Ultimately, the model which scored the highest in a concept scoring matrix, available in Appendix D, was the Linear Long Vacuum with a 3.474, but its score was affected by many components, as were the other designs. In an effort to maximize effectiveness of the product, elements were selected from each model. For example, while twin fans would increase flow speed, it would also mean a more difficult to produce, and thus more expensive, and more failure prone product. As such, the team selected a long linear body with a single turbo fan. In addition, the reusable cloth filter of the Twin Fan Supercharger was selected, along with the safety features of both the pressure sensitive switch and the filter engagement safety mechanism.

4. System Level Design

4.1 Overall Description:

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Above, in Figure 7, the basic layout of the Team MSM vacuum is shown. It will

consist of a tubular body, with a taper to a extendable hose for easy vacuuming in hard to reach places. Both the removable battery pack, which is compatible with the existing line of DrillMaster tools, as well as the main carry handle will be located at the top of product. In addition, on the handle there will also be the pressure sensitive switch to activate the vacuum. Driving the fan, the drive shaft of the motor will be located 6 inches from the filter, which is located at the rear of the body and is held in place by a transparent housing which is 7.5 inches long.

Additional images of the product, including full renderings and drawings are available in Appendix E. 4.2 Preliminary Theoretical Analysis:

As a result of testing the supplied motor and battery, the output torque and power of these components was able to be studied in relation to efficiency and rotational speed. Through this benchmarking, it was determined that the motor should be run at full throttle to reach peak efficiency. This is an advantageous result: through external research it was found a high rotational speed is vital to a high performance vacuum. Due to this, and the fact that the drill already includes a rudimentary gear box, it is possible to adjust the gearing to reach optimal torque and rotational speed to maximize the flow rate of the vacuum.

A majority of the patents researched utilized a turbofan, shown in Figure 7, similar to the one integrated into this design. Therefore, its performance should be suitable for a prototype and further refinements to the fan geometry will result in a high performance vacuum cleaner.

With a restricted budget of $30, the design of the vacuum will be made of aluminium material for the outer shell due to the material’s low weight and cost as well as its endurance properties. The filter housing will be prototyped accordingly by using rapid prototyping techniques to produce the housing with a transparent material.

5. Detailed Design

The complete prototype is displayed in Figure 8 . It consists of 9 mechanical entities (with diagrams available in Appendix E) and 4 electronic components. The mechanical components include: a PVC pipe, 6 inches in length, to house the electronics; a base plate that slides into the pipe and to which the motor and vacuum casing attach; a shell that makes up the vacuum casing that is circular in shape with an

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inlet at the top of the shell and a tangent outlet at the periphery; a plastic weaved cloth filter bag; a PVC pipe and nozzle assembly at the inlet of the vacuum; an ergonomically shaped carrying handle; and lastly, a fan mounted on the shaft of the motor, between the base plate and the vacuum casing shell. Additionally, the lower handle of the drill is attached to the PVC pipe to act as a solid mounting point for the battery.

The electronic components of the drill include a motor, a push button single pole single throw (SPST) switch, and an 18VDC battery and its corresponding electrical connector. 5.1 Modifications to Proposal:

Since the proposal’s submission, the design of the vacuum casing has been modified. Where it was previously a long linear design,it is now based on a circular form. The drawing for the components of this design are available in Appendix E. This redesign of the casing allows the motor and electronics to be sealed away from any dust or airflow, thus reducing the risk of damage to electronic components. In addition, it lends itself to a modular design: now the casing can be made of a base plate and an upper casing instead of one large tube.

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5.2 Final Theoretical Analysis:

Assumptions: For the fans to be tested, the diameter is 3 inches. The three penultimate fans

include the conic fan with a shroud across the blades, a circular fan with cupped blades, and lastly, the turbo fan. Using the “Little Giant” vacuum pump as an analogous model, the output speed of the motor is 5000 rpm, the volumetric flow rate would be from 0 to 280 in gallons per hour. The head loss was compared to the “Little Giant” by obtaining the Reynolds number and computing the head loss with a different fan diameter through scaling methods.

To scale, affinity laws were utilized, the team interpolated the provided data points to compute the expected head vs. flow rate curves for the designed fans. The output speed of the motor, 8500 rpm, was also factored into the affinity law calculations. With the application of the affinity laws, the results were generated with simple algebra.

Result analysis:

In Figure 9, the volumetric flow rate versus the dynamic head is displayed. The graph shows that each fan has an optimal point that balances flow rate with the pressure differential to lift heavier debris. This analysis, based on scaling the “Little Giant” vacuum pump, allowed the team to analyze the effects of fan diameter, sizing, and rotational speed on both volumetric flow rate fluid head. The graph provides an expected baseline for the relationship among the speed of the motor and the diameter of the fan with the volumetric flow rate and the head mechanical friction. The base data of the three fans are available in Appendix F.

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5.3 Components and Materials:

The vacuum casing components, including the base plate, upper casing, nozzle and both the airflow tube and body (prototyped from PVC pipe), will be made from an ABS plastic since it is an inexpensive, common material that lends itself to a rigid vacuum housing. In addition, some components prototyped from PVC will be combined with other components: the handle will be combined with the vacuum body into a single piece, and the nozzle and air flow tube will also be consolidated. Next, The production fan will be composed of polyethylene plastic, due to the dense molecular arrangement which will ensure that the fan has a high durability. The filter will be composed of a fabricated transparent plastic weaved cloth that will have a circular tightening ring clamp on the inlet of the filter to firmly hold it in place. This clamp will be able to be operated without tools, utilizing a thumbscrew to loosen and tighten and will offer a sturdy and convenient method of attaching the filter to the vacuum.

Several pre-produced components will also be used: a 540 specification motor, an 18VDC battery pack and corresponding electrical and mechanical connectors for the pack, a single pole single throw (SPST) push button toggle switch, approximately 18 inches of 18 gauge wire, a circular tightening clamp and lastly, several fasteners and a circular gasket to seal the vacuum chamber. 5.4 Fabrication Method:

To produce the vacuum, all ABS components listed above will be injection molded.The push button switch will then be connected to one 4” wire and one 8” wire that will connect it to the motor and battery which are run down through the handle. Then, the switch is mounted at the middle of the handle,and the handle affixed to the body of the vacuum. Next, the motor will be attached to the base plate, and the SPST switch 4” wire will be soldered to the motor, the 8” lead is soldered to the battery connector and lastly a 6” length of wire will run from the other motor terminal to the unused battery connector terminal. The electrical connector is then inserted into the battery mount, which is inserted into the back of the vacuum body and fixed in place with carriage bolt that passes through it and the body. The motor-base plate assembly is then inserted into the injection molded body, held in place by molded plastic clips. The electronic components of the vacuum are now complete and sealed.

The fan will also be injection molded (from polyethylene), and once molded will be press fit to the shaft of the motor with adhesive applied to the motor shaft. Next, the vacuum casing is mounted on top of the circular gasket and base plate to seal off the vacuum chamber, with two screws at either end being tightened to mate these parts. Lastly, the nozzle/airflow tube component will be mounted to the inlet of the vacuum chamber using a plastic epoxy to seal the joint of the parts and hold it rigidly in place.

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In addition, the filter will be made on a separate construction line from the main vacuum. It will be produced by folding and stitching the plastic cloth into a bag, and then inserting the open end of the bag into the circular tightening clamp, folding the cloth over clamp and applying adhesive so the components remain together. The filter will not be shipped attached to the main vacuum so that the consumer packaging is more space efficient.

5.5 Industrial Design:

The controls of the vacuum will be simple and easy to use. This is achieved by using a single on-off push button switch, located conveniently on the handle, that provides the user with a clear, tactile indication that the vacuum is on. If the vacuum is on, the switch will be loose and capable of moving freely up and down, while if it is off, the switch will be stiffly locked in the uppermost position. In addition, a bag will be used to collect the dust and the debris that have been vacuumed. This bag was selected because it offers quick and easy detachment via a clamp at the outlet of the vacuum that will hold the bag firmly in place against the vacuum outlet. This clamp will be operated with a single thumbscrew to tighten and loosen it, which makes the bag able to be securely attached with little effort. The bag will be located on the bottom of the vacuum to keep it out of the way from the handle, as well as to allow gravity to optimize performance. Lastly, the vacuum will feature a moderately long nozzle which, combined with the vacuum having a thin profile, will allow the user to vacuum in hard to reach places.

5.6 Detailed Drawings:

Detailed drawings of the vacuum components can be viewed in Appendix E, followed by renderings and photographs of the final prototype. The first component illustrated is the upper vacuum casing, followed by the vacuum base plate and body of the vacuum. Next, the three fans which were considered and tested for use in the final prototype, the handle for the vacuum, the battery and battery mounting socket and lastly, the nozzle and tube for the airflow intake are displayed. 5.7 Economic Analysis:

To determine the cost of producing a single unit, several component prices were compiled. In the final product, there will be an estimated 4 pounds of ABS plastic, using an average cost of $2391 for 1 ton of ABS provided by Recycle In Me [Reference 12], the team estimated that a single unit would cost $4.78 in raw materials. For off the shelf electronic components, sourced from Mouser [Reference 13], the switch would cost $0.39 per unit, and the motor would cost approximately $3.00. The battery will cost approximately $5.96 for the NiCd cells. The filter bag will cost approximately $3.50 to

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produce as well. Therefore, the estimated operating cost without labor or facility costs to produce one unit of the vacuum would be approximately $17.63. A complete bill of materials is available in Appendix G.

Concerning tooling, x injection molding machine will cost approximately $80,000 [Reference 14] and the molds for the vacuum casing, vacuum base, and fan were quoted at $6,194, $2,820 and $3,505 [Reference 15] respectively. In total, the necessary equipment to produce the vacuum will cost $92,500.

In addition, there are development costs associated with this product. According to Michigan Tech [Reference 16], the mean salary for an engineer is $87,000. Therefore, with a team of three engineers working on the product over the course of one year, the total development cost is $261,000.

Although there are substantial starting and operating costs, a net present value (NPV) analysis was carried out to determine if this project was a worthwhile investment [Taken from lecture 21]. The results of this analysis are shown in Appendix G, and they illustrate that there is a significant opportunity for profit. Assumptions made for this analysis were a $70 market price for the product and the vacuum being put on the market in December of 2016. Other assumptions include a discount rate of 10% and an annual production of 100,000 units. 5.8 Safety:

The vacuum design meets the requirements of relevant consumer safety regulations for sale in North America and European markets. Based on the UL 1017 safety standard [Reference 17], the vacuum is well insulated from electrical current on the exterior, the battery pack contains cells which are shielded from possible contact, and the operating switch is similarly insulated from any electrical discharge to the user.

In addition, the vacuum will be produced with a rigid casing that will endure vibrational motion. The orientation of the components in the vacuum are also designed to prevent any harm to the user, through coming in contact with moving parts such as the fan or potential electrocution. Lastly the casing is capable of enduring the movement of inner parts, large temperature changes, and impacts from normal usage. 5.9 Prototype Manufacturing Process

A preliminary set of five fans, a upper casing and a base plate for the casing were rapid prototyped for initial testing. The motor and trigger switch were removed from the drill and mounted to each of the fans within the vacuum casing for testing.

After testing the alpha prototype with the original five impellers, the team selected the three most promising impellers through testing (shown in section 6) and further revised them. Thus, one impeller was selected based on performing the rice test listed

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below. The selected fan only needed 16.8 seconds to clean one cup of rice. This impeller was permanently attached through the use of a solvent based adhesive.

After selecting the impeller to use, several components were added that weren’t directly related to the airflow of the vacuum. The team designed a handle to be rapid prototyped with an opening to implement a push button toggle switch. Next, the battery mount was produced by cutting the lower half of the drill handle from the drill body and drilling a ⅜” hole through both it and the vacuum housing piece of PVC pipe. After a slot was cut into the housing piece to allow the battery mount to be recessed inside of the housing, a 4” carriage bolt was driven through the PVC pipe and the lower half of the drill handle to attach the two components. Lastly, the wires for the switch and motor to connect to the battery were run through the housing and through the handle, and the handle was affixed to the housing body with adhesive.

At the intake of the vacuum, a PVC air flow tube and nozzle were attached with rubber adhesive. Concerning the outlet of the vacuum, a mesh filter bag was created by using fishing line to sew a long circular bag out of flat mesh fabric. Once the bag had its basic shape, a circular tightening clamp was put over the opening of the bag to attach it firmly to the vacuum.

Images of the completed prototype are available at the end of Appendix E.

6. Testing 6.1 Testing Goal:

To provide a benchmark of the several fan designs the team produced, a repeatable test was developed which compared the fans in the same vacuum casing and using the same motor and battery. The test will consist of two phases: the first will test the ability of each fan to clean up small shredded pieces of paper. Of the fans, the the fastest at cleaning would be revised and strengthened to then repeat a similar test with rice instead of paper. For the Beta prototype, the fans shown in Appendix E were revised and re-prototyped for the second test. The second test will demonstrate the capability of the fan and the vacuum to be able to clean up one cup of rice in an environment similar to the final competition. The final fan will then be selected and revised after this examination. In addition, the final fan will also be tested with and without a nozzle to see if it yields significant performance improvements. 6.2 Testing Procedure:

The procedure used to test the prototyped fans is listed in Appendix H. The test of the Alpha prototype consists of several steps that are repeated for each fan design using shredded paper as a substitute for one cup of rice. This allows for a uniform

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evaluation across each fan. The second phase of the test also mirrors the first phase, and this creates consistency across the different phases concerning experimental data formats. After revising and improving the design of the selected fans, the test will be repeated using a cup of rice as a demonstration of capability in a setting similar to the final competition. After the final fan has been chosen, the test will be repeated with the final fan, alternating between the use of a nozzle at the vacuum inlet and without. 6.3 Testing Results:

The results for the paper test are available in Appendix I. Overall, the fan designs which cleaned the paper most efficiently were a conic fan with a shroud over the blades which experienced minimal damage and completed the test in 3.48 seconds; a fan with cupped blades that underwent no damage and performed the test in 3.78 seconds; and lastly a turbo-fan like impeller which had several vanes break off, but still completed the test in 3.39 seconds.

Revisions to these fans include implementing thicker vanes and a slightly wider profile in the case of the turbo-fan, labelled impeller_3 in Appendix E; and a revision of the mounting hole for the cupped fan blade, labelled impeller_4 in the Appendix E.

Of the three fans, only one was able to perform the test adequately and within the customer specifications, the turbo fan labelled Impeller_3. It was able to clean up the cup of rice with a time of 16.8 seconds. The cupped blade fan was tested but could not complete the test without being damaged. In addition, it produced significant noise which was contrary to the team’s customer specifications. Lastly, the shrouded fan, labelled Impeller_5, was incapable of vacuuming the rice since the rice grains were larger than the shroud would allow to easily pass through. Thus, the turbo fan was selected to be refined even further for use in the final prototype. It was able to clean up the rice in 16.8 seconds.

Next, concerning the nozzle, it was found that it caused the vacuum to save, on average, 6 seconds. Accordingly, the nozzle was selected for the final prototype. Results of the nozzle testing are also available in Appendix I.

7. Conclusion and Recommendations

The team has developed internal and external ideas into the basic shape of the vacuum and the major components of the design and produced a final prototype of the vacuum cleaner.The prototype includes a casing for the vacuum chamber as well as a housing which provides storage for electronics and an ergonomic carrying handle. This project’s main goals are to create a safe, comfortable and powerful vacuuming experience for the customer in the $70 price range. A comfortable and easy to use form

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factor will make the vacuum appealing to the customer, and an efficient and powerful fan design will give the customer ample cleaning power.

The potential market for this product is household users and cleaning service enterprises. Since this vacuum will have higher performance than others in a similar price range, the customer will be able to clean dust and dirt efficiently. With a modest price and a high standard of performance and quality, the Team MSM Vacuum is an ideal choice for the customer.

The vacuum, however, will need to be developed further to include a more effective catch mechanism for the outlet of the vacuum. Currently, it is unable to catch small dust particles. Suggested additions were a finer mesh for the bag or a secondary plastic casing over the bag to catch small dust particles. Additional iterations of the design will also provide improved designs of the fan, which, due to the tight clearance between fan and casing, will grind the rice. Optimizing the balance between performance and the rice staying intact as it moves through the vacuum will be necessary. Also, a more easy to use mount for the filter bag and an ergonomically comfortable weight balance of the vacuum will be implemented in subsequent designs.

This project has influenced our team to foster creativity, diversity and responsibility. The necessity of teamwork in a project of this magnitude has taught us to share our knowledge and ideas by participating and allocating time throughout the development of the vacuum. It made us take healthy risk decisions and take responsibility for flaws and successes through each step of the design process.

All in all, this vacuum is relatively inexpensive to produce while still providing a customer experience worthy of its market price. Utilizing an NPV analysis, this product has also been shown to be profitable for the investors. Furthermore, through technical analysis and iterative testing, Team MSM has found this to be a vacuum that will perform efficiently and clean with ease. Ultimately, the Team MSM handheld vacuum cleaner provides an optimal product for both customer and investor alike.

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8. References

[1] Memo 1 Vacuum cleaner external search [2] Cordless Vacuum Project Description Fall15.pdf [3] Team MSM Contract [4] Karl T. Ulrich, Steven D. Eppinger. (October 1994). Product Design and Development. New York: McGraw-Hill. [5] Patent No. US 5561885A [6] Patent No. US 5664282 [7] Patent No. US 20091787A1 [8] Patent No.US 6883201B2 [9] Patent No. US 649390B1 [10] Patent No. US 20050011038 [11] Amazon Marketplace http://www.amazon.com/b/ref=sr_aj?node=510114&ajr=0 [12]http://www.recycleinme.com/scrapresources/detailedprice.aspx?psect=2&cat=Resin%20Prices&subcat=ABS [13] http://www.mouser.com/ [14] http://www.alibaba.com/showroom/injection-molding-machine-price.html [15] http://www.protolabs.com/ [16] http://www.mtu.edu/engineering/outreach/welcome/salary/ [17] http://www.zhilitong.com/others/zizhi8.pdf

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9. Appendices Appendix A: Gantt Chart for project

Appendix B: QFD Table for Handheld Vacuum

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Appendix C: Analytical Hierarchy Process Table for Handheld Vacuum specifications

Appendix D: Weighted Decision Matrix for potential Vacuum designs

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Appendix E: Additional Views and Drawings of Handheld Vacuum

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Appendix F: Data and Graphs of Theoretical Analysis:

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Appendix G: Economic Data

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Appendix H: Procedure of Testing Fan 1. For paper:

a. Cut one piece of 8.5”x11” sheet of paper into 5 even sections b. Dice each section of paper into small pieces, about .25”X.25” squares,

placing the five sections into separate piles. c. Take diced paper from one of the five piles of paper and set it out on top

of the worktable, spread out so the area covered is about 1 square inch. d. One person will time the test by counting down from three and telling the

individual vacuuming the pieces to go while simultaneously starting the stopwatch.

e. Vacuuming will continue until the tester cleaning the table says done, at which point the stopwatch will be stopped.

f. Record the time and indicate the fan design that was tested. g. Disassemble vacuum and examine fan for any damage, take note of

damage below time. h. Reassemble vacuum with next fan to be tested. i. Repeat steps 1.c through 1.h until all fans have been tested.

2. For Rice: a. Scatter rice over a 3 square inch area b. Repeat steps 1.d through 1.h until all revised fans have been

tested. 3. To test nozzle with selected fan

a. assemble vacuum with selected fan from 2 b. Repeat steps 2.a through 2.b without a nozzle at the end of the air flow

tube c. Repeat step 3.b with nozzle in place

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Appendix I: Testing Result of Different Fan and Airflow Configurations

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