MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
SUBMITTED BY Senior Design Team 4 Alyssa Eng, Cesar Gutierrez, Annie Mroz May 6, 2013
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
TABLE OF CONTENTS
PROJECT OVERVIEW ............................................................................................................................................................... 3 OVERALL DESIGN .................................................................................................................................................................... 3 TESTING/PROTOTYPING RESULTS .......................................................................................................................................... 3 PROPOSED IMPROVEMENTS/LESSONS LEARNED .................................................................................................................. 3 REQUIREMENTS COMPLIANCE ............................................................................................................................................... 3 COST ....................................................................................................................................................................................... 4
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
PROJECT OVERVIEW PROBLEM STATEMENT Lack of access to water presents significant barriers to growth and opportunity in developing countries. People who live in rural areas often have to spend several hours each day collecting water, due to the fact that their water source is very far from where they live and they are limited to what they can physically carry. These hours spent collecting water take away time from work, leisure, and study. Current solutions to the problem such as hand pumps or boreholes are typically expensive, complex, and fragile. Water access without electric power or expensive water infrastructure could be an optimal solution to this problem. HIGH LEVEL CONCEPT To address these issues, our project simultaneously solves the problem of lack of water and of electrical infrastructure by providing both the ability to move water and charge small devices. This is accomplished with a self-‐contained bike system in which the user provides manual power to both applications by pedaling. To charge devices, the user pedals and the back wheel of the bicycle turns a roller via friction contact. This roller is connected to a generator that provides electric power to charge a battery or power small USB devices. To move water, the bike transmits pedal power to an external gear via an extra bike chain, and this extra gear powers a pump. REVISED PROJECT METRICS Flow Rate
3 GPM
Pump Head
15 m
Generator
Charge 12 Volt Battery Charge cell phone or small appliances via USB
Cost
$20 - $100
Materials
Incorporate recycled materials where possible. Use as many recycled bike parts as possible.
Additional Goals
Portability, usability, ability to use any bike, ease of set up
NOVELTY After much research, we realized that bike-‐water projects abound, and that several others have already attempted this. However, our product is different than existing bike-‐water projects in several ways. The main differentiation between our project and others is that the bike can still be ridden and as such, the entire system is portable. Any bike can easily be dropped into our system without any significant modifications and that bike can be as easily removed. In addition, the entire product is inexpensive and made primarily from recycled bicycle components. 3 | P a g e
MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
OVERALL DESIGN As mentioned before, the goal we pursued with our project is solving the problem of lack of access to water in developing countries, as well as providing a inexpensive and reliable source of electrical power for small electronic devices such as cellphones or LED lights. The ultimate purpose being to improve the quality of life of people (specifically kids) in developing countries, by allowing them to save time doing chores for study or play. To accomplish this, we designed a universal, portable power providing system consisting of a bike stand in which you can drop any multi-‐gear bike. This stand can easily be attached to any bike, and the bike does not require any complex modification. The only modification to the bike consists of adding a second chain to the rear gear. This is required to implement the double chain system which powers the water pump. This task can be done in less than 10 minutes and without the need of any specialized or expensive tools. Once the stand is attached to the bike, the bike can be ridden as usual (so the entire system is portable) but at the same time has the capacity of pumping water and generating electricity. The setup of the generator system takes no longer than 10 seconds, and the setup of the water pump takes about one and a half minutes. With our portable power providing system we are simultaneously tackling many of the problems mentioned before. First and foremost, we hope to provide people with more convenient access to water and electricity. This will give people the opportunity to use their extra time for work, study or leisure. Besides this, we are creating work for an enterprising entrepreneur, not only for the owner of our device but also for a mechanic or welder who can build and sell our design. We envision an entrepreneur in Kenya could make an initial investment to purchase or fabricate the device and then provide a service for his fellow villagers. This model of single ownership will ensure that the device and all its subsystems are well maintained. Additionally, we hope that this model will enable an unemployed villager to earn additional income. If the concept of bike power were to become a business, it could be used to solve a number of problems in Kenya. With the help of our advisor Dr. Jackson, who has in-‐field experience, we learned that villagers often collect rainwater but have no way of pressurizing it for sinks and faucets. Our product could easily address this need by pumping water from a ground-‐level rain barrel to a secondary storage container 5-‐10 m off the ground. These issues were present in every step of our design and redesign processes, and we made several major changes in our design with portability and simplicity being our priorities until we reached the final optimal solution. To achieve these goals, our project is designed to be easy to build with the resources available in Kenya. For this reason, we decided to use as many old bike parts as possible, since bikes are very common there. Welding is also a common resource in Kenya, where it is not difficult to find a welder in any village. They also have access to scrap metal which can be welded together to construct most of the structures required by our design. Although we aimed to use as many recycled components as possible, we did not limit ourselves to using recycled parts when it was impractical or unnecessary.
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
Detailed Overview Bike stand: The stand is the base of our system. It´s main purpose is holding the bike stationary while the user pumps water. It flips up to form a rack when the bike is being ridden as a regular bike. It is also the support for the two main subsystems: the water pump and the electric generator. The bike stand functions as follows: Although our first idea was manufacturing our own bike stand out of repurposed metal bars obtained from an old bicycle, the lack of access to welding resources and the delays that would entail by having it welded by an external source were prohibitive. We decided instead to buy the bike stand to save time. This stand is originally a bike trainer for at-‐home cyclists. This triangular structure has 2 screws on the top corner of the triangle. These screws attach to the axle of the rear wheel of the bike lifting the rear wheel to make the bike stationary. The screws allow the stand to rotate around the point of contact with the bike. We took advantage of this feature to design our system in such a way that the stand can be flipped up and be held in that vertical position via a bungee system. By doing this, the stand that originally provided a stable platform to hold the bike now provides a flat surface on the back of the bike, similar to a rack. This surface can be used to accommodate a crate in which the user can carry all the tools needed, as well as the main components of the other subsystems: the water pump, the battery, the inlet and outlet hoses that will be connected to the pump, and tools. Rack and crate: In order to take advantage of the flat surface that provides the stand when it is flipped up, we created a quick release system to accommodate the crate in a secure way. To do so, we used a repurposed the seat stays (piece of tubing connecting the main frame to the rear axle) of an old bike. The shape of this part makes it ideal to mate with the stand, and it is secured in place via a bungee cord as well as a peg and slot system. The assembly and disassembly of this system takes no longer than 10-‐15 seconds, and its utility resides in its ability to carry all the tools and components in an easy way, keeping the bike balanced and not interfering with the natural pedaling motion. To absorb the vibration that may be caused by riding the bike in rural areas, all the contact points are cushioned with rubber. This also increases the grip between removable parts. Water pump subsystem: The purpose of this subsystem is transmitting the power from the pedals to a secondary output shaft that drives the water pump. After several iterations and redesign steps, we decided to create a double chain system because it was the most optimal solution that fulfilled our requirements of efficiency, portability and simplicity. The benefits of using this double chain design are as follows: The power transmission has high efficiency in chain systems, up to 95% in well-‐lubricated and tensioned systems. The design is robust and compact. The second chain is permanently attached to the output shaft, even when the pump is not connected and the stand is flipped up. Thanks to this, the device is portable and the setup time is drastically reduced, to the point that it takes no more than 1 minute and 30 seconds from the moment the user arrives to his destination riding the bike until the moment he is actually pumping water. Since the output shaft is well lubricated, the power loss due to friction when it is freewheeling (with the pump disconnected) is negligible. In addition, the second chain can be obtained from and old bike. The output shaft, which is welded into the stand, is a repurposed bottom bracket (the axle that the pedals rotate on) of an old bike. Custom-‐made couplers attach to both sides of this axle. The couplers connect the water pump on the outer side and the extra gear system on the 5 | P a g e
MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
inner side. These couplers have been machined with a tapered hole that mates perfectly with the shape of the axle from the old bike making it easy to attach or remove them. The quick connection of the pump consists of a setscrew through the axle of the pump and a wing nut. In order to prevent the pump from freewheeling, we designed a small stand for the pump that sits on the ground and accommodates the circular shape of the pump. The pump is a positive displacement pump, specifically a rotary vane pump. We chose plastic because it is light, durable, resistant to corrosion and inexpensive. The tubing is the same for the inlet and the outlet. We used ¾” clear, vinyl tubing. The ¾” hose diameter was chosen based on the results of our Matlab model (implementing the Colebrook equation for frictional losses). The model predicts the pressure lost depending on the flowrate, distance and height to which you are pumping. Another important parameter that was taken into account was the weight of the hose. The inlet tubing is 15 feet long and the outlet is 90 feet. Minimizing weight was important so that the user could have a long enough hose to make it useful for pumping distances but at the same time practical and portable. To make the transportation of the hose easier, there is enough clearance between the crate and the seat of the bike so that the hose can be coiled around the crate. The connection between the pump and the tubing is made via standard gardening hose connections. A check valve is attached to the outlet of the pump to prevent back flow allowing the user to take a break without losing pressure. In the inlet hose we attached a small filter to prevent debris from getting into the pump, damaging the mechanism. The inlet of the hose is weighted, so that it stays submerged preventing dry-‐running of the pump. On the other side of the output shaft we have an extra gear system, entirely made out of repurposed bike parts. The main part is the rear gear hub, which is screwed to the coupler mentioned before. This rear gear hub accommodates several laser cut spacers and the biggest gear of an old bike cassette. The spacers allow the user to place the gear in the desired position. This is important as the second gear needs to be in the same plane as the biggest gear of the cassette of the main bike so that the second chain is aligned, reducing friction and consequently increasing efficiency. The second chain links the biggest gear of the cassette of the bike with the gear on the output shaft. With this setup, the gear ratio between the pedaling motion and the RPM in the output shaft, and consequently in the pump is 3/2 (assuming that the user chooses the recommended gear ratio). The placement of the second chain is such that does not interfere with the derailleur of the bike, so the user can still switch gears as desired, except for the biggest two gears in the cassette, which are occupied by the second chain. This exception, however, is not a big inconvenience since those are less-‐commonly used gears. It should be noted that although the primary purpose of this extra axle is to pump water, it could easily be used for any other application that requires rotary motion, such as a grinding mill or knife sharpener.
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
Electric generator subsystem: The lack of electricity inhibits education and studying for young people. Children often must spend most of their daylight hours doing chores (such as collecting water) and by the time they are done with their work it is already dark and therefore they have no light to study by. For this reason, we added a small electrical generator to our project. The generator is powered by the wheel of the bike in a roller-‐fashion. The generator can be engaged anytime, not only when riding the bike from one place to the other but also when the bike is stationary or while pumping water. It can be connected to a 12V battery or directly to any electronic device that uses a USB port. This way, the battery can be used to power LED lights or to charge cellphones, or the cellphones and LED lights can be charged directly. The user can decide which option is more convenient at any time and change from one to the other by flicking a switch. The generator is supported by a custom aluminum plate which is screwed into the back of the bike stand. This plate can rotate around a fixed point in the stand until the generator gets in contact with the wheel, and it can be locked in place by adjusting a set screw with a wing nut. Power is transmitted to the generator in a roller-‐fashion because it gives the user a high gear ratio, which in turn allows the user to easily generate a high RPM in the generator. Consequently, it is easy for the user to generate a high voltage in the generator even while pedaling at slow speeds. Because the generator is AC, we designed a compact circuit that rectifies the voltage via a bridge rectifier. It also allows the user to choose between “battery mode”, in which the battery can be directly connected to power and ground outputs or “USB mode”, which can be used to connect any USB device. Cell phones are quite common in Kenya but charging them without access to electricity is a constant struggle. In order to charge their phones, owners typically have to leave their village and walk a long way until they have access to the grid or to a diesel generator where they can pay to get their phone charged. The entire circuit is housed in a small box which remains attached to the bike stand but that can be disengaged at any time. The whole system works as follows: Once the owner of the bike arrives to the place where he would like to pump water, he flips down the stand to make the bike stationary and connects the water pump to the exterior side of the axle. After that, he has to connect the inlet and outlet hose and place the pump stand right under the pump. Then, the last step is to drop the inlet hose into the water source and the outlet hose to the desired storage vessel. After that, he can start pedaling to pump water. This whole process shouldn´t take more than one and a half minutes. Also, as mentioned before, the generator can be engaged at any time. Since the amount of power that it extracts is not very great, it can be engaged when riding the bike from one place to the other, taking advantage of the time spent travelling. Once the user decides to start pumping water, he can leave the generator engaged if the head he wants to pump to is not too high, or he can just disengage it to transmit all the power to the pump. Once the process of pumping water is over, the packing process is the same as the setup process but in the opposite direction: he has to disconnect the hoses and the pump, flip up the stand and secure it with the bungee system and place the rack and the crate on top of it, again using another bungee system. To conclude, he has to put the pump, the pump stand and the hose in and around the crate respectively and he is ready to ride his bike to a different location. 7 | P a g e
MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
TESTING/PROTOTYPING RESULTS Setup and Methods Numerous rounds of testing were conducted both to test component integration and system performance. Pump testing was conducted by pedaling the bike and measuring the flow rate of the water as well as the pressure head generated. Testing was done at a gentle power input to simulate the ability of someone pedaling for an extended period. We tried testing with two different pressure gauges, neither of which provided any useful measure of pressure head within the system because of constant fluctuations. As such, we resorted to calculating the pressure head based on pumping to different vertical heights. This is not truly a measure of the pressure built up in the pump as it doesn’t account for frictional losses in the tubing, but it provides a good lower bound of pump capabilities. Testing was performed in Skirkanich, with the bike on the ground floor and someone on a different floor measuring the flow rate. We also tested outside near Penn Park to simulate what it would be like to actually use the bike outdoors up a more sloping hill. We set up the bike with a bucket of water at the bottom of the hill and again had someone at the top measuring flow rate. The height of the hill was about 15 feet and at a leisurely pace we achieved a flow rate of about 4 GPM. We also tested the electrical components of our product. Current and voltage output from the generator were tested with a digital multimeter while one person pedaled. The generator was also tested by charging a cell phone, both while stationary and riding. Cell phone charge time was measured to give an indication of generator performance. The aspect of testing that we struggled the most with was that we couldn’t measure power input. There was no way for us to practically measure power output of the person pedaling, so we had no way to validate our model. The best we could do were smart estimates. However, because the goal of our project was to pump water and generate electricity, most of our testing focused on simply getting the system to work. Prototyping effect on design Doing a lot of testing early on was key in ensuring system functionality. Our initial tests were promising (we were able to pump water via pedaling), but were not ideal. As of the submission of the midterm report, our design made use of an extra gear engaged with the main bike chain. This required a lot of tension to be added to the derailleur (40-‐60 lbs.) which was more than was practical via any additional tensioning system. All of the designs we tested to add tension to the chain were bulky and awkward. We also noticed after testing our system several times that applying such great tension to our derailleur was permanently deforming it, and we nearly broke it. Doing a lot of testing and playing around with different ideas for power transmission led us to the double chain system. At some point in all of our design iterations, we had been contemplating the double chain system, but had discounted it. We were doubtful because the extra chain would absorb one of the gears rendering it unusable, and we were worried about space constraints. We were also concerned that a double chain system would require the user to remove the chain with every setup and breakdown of the pump. Examining the bike, we realized that the double chain could be permanently engaged with the back gear to prevent this issue. Prototyping confirmed that 8 | P a g e
MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
this designed functioned well given the space constraints and that the extra chain could remain on the back gear without problems. Leaking was also an important factor in our testing, and we experimented with thread tape and sealant as well as different types of hose connectors to see which ones worked the best. Results of Testing Our final round of testing gave us the following results for our pump:
Height (meters)
Flow Rate (GPM)
4.70
6
9.25
4
13.25
2
From our initial generator testing, it was clear that we could easily output over 12 Volts. We even found that we could generate voltages larger than 12 Volts while pedaling at an easy pace. After our circuit was complete, we tested it by charging a cell phone. Our generator was able to charge a cell phone from 0% battery to 20% in 20 minutes, similar to charging via wall outlet. Additional applications such as a bike light were also hooked up the USB port and charged easily.
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
PROPOSED IMPROVEMENTS/LESSONS LEARNED Along the process of designing and manufacturing our project we faced different problems ranging from the lack of access to some resources (as welding) to the strict constraints in terms of cost and materials. Because simplicity, reliability, portability, low cost and manufacturability in developing countries were our main goals, we struggled to find materials and components that met these requirements while still being useful in our design. One of the biggest lessons learnt during this process is how to design and manufacture what we had in our minds while being subject to the constraints mentioned. We realized that the easier design is usually the better one. One major breakthrough that we had is that using repurposed parts from old bicycles was an optimal solution balancing practicality and our initial goals of using all recycled material. Bike parts are cheap and easy to find in developing countries. They are universal and easy to understand and fix, which we considered really important to implement our system. Besides this, using bike parts that are already manufactured drastically reduces the complexity, number of tools, and time required to construct the system. This way, the whole system can be made by a welder by just using and old bike (from which he would take the bottom bracket, the chain, the rear gear hub, the cassette and the seat stays). The frame of an old bike or scrap metal could be used to build the stand instead of having to buy one. If we had to do this project again, we would make several changes. Due to the lack of access to welding facilities, we decided to buy a bike stand. Although this stand works well, it is heavy and expensive. The stand alone was as expensive as the water pump and the generator together, and it represents the majority of the extra weight added to our design. Since the design of the stand is really simple, we are confident that it could be made from the frame of a scrap bike. That would make the design lighter and cheaper. Another feature that we would like to change for a second iteration is the integration of the output shaft. In our current design, the shaft is welded into the frame in a fixed position. This system works efficiently, but has some drawbacks, mainly the initial setup and adjustment of the second chain. Because the shaft is fixed in place in our current design, the user has to modify the length of the second chain to accommodate whatever extra gear he uses. In some instances, he may not be able to use the gear size he wishes because chains come with a discrete number of links, and as such only certain size gears will work. Further, although this is a setup need only be done once (since after the first setup the chain is going to be permanently engaged), this process could be made easier. We thought that having the output shaft mounted in a rail system along the frame of the stand would make the system more user-‐friendly. It would not only make this initial setup easier but it would allow the user to change the gear on the shaft fast and easily. Although the current gear ratio is optimal for pumping water, the user may be interested in a having broader range in order to power other potential functions. Other improvements that could be proposed for a second iteration of this project are the implementation of a compact water filtration system or a hose system that could be used for irrigation. Last but not least, another improvement that would like to propose is to make the whole electric system waterproof. Although we know that our generator is water resistant (it is meant to be used for outdoor purposes such as wind turbines), we could not verify that capability. Further, the USB port and the connections for the battery are exposed. Although the whole electric system can me removed easily to prevent it from corrosion in the case of rain, we think that is necessary to make it completely waterproof because the device is mainly meant for outdoor use. 10 | P a g e
MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
In terms of the lessons learnt, apart from the constrained design mentioned before, we also learnt the importance of system integration. The fact of having different subsystems working smoothly and perfectly does not imply that they are going to work once they are put together. That was one of the main challenges we faced during the design of the double chain system. Due to the presence of the derailleur and the tight space between the bike and the stand we had several issues with parts interfering with each other, which made us make several redesigns until we found the final solution.
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
REQUIREMENTS COMPLIANCE Initial Goals: Flow Rate
13 GPM
Pump Head
0.5 miles (horizontal)
Cost
$20 - $100
Materials
Entirely recycled or scrap
Our initial goals were set before we fully understood the needs of people in developing countries and the limits of human abilities. Because of this, they are a little unrealistic. They’ve since been scaled back while keeping in mind customer’s needs. Furthermore, we added in several new quantitative and qualitative metrics. Revised Goals: Flow Rate
3 GPM
Pump Head
15 m
Generator
Charge 12 Volt Battery Charge cell phone or small appliances via USB
Cost
$20 - $100
Materials
Incorporate recycled materials where possible. Use as many recycled bike parts as possible.
Additional Goals
Portability, usability, ability to use any bike, ease of set up
As our design went through several iterations, our priorities and design focus changed. We abandoned the goal of making the project from completely recycled materials for several reasons. Requiring that the entire project be made from recycled materials came to be viewed as an impractical and unnecessary constraint. Instead, we attempted to incorporate recycled materials, especially any type of bike part, when practical and feasible. The team decided that making certain components, the pump for instance, out of recycled material, was an unnecessary step as pumps are manufactured to specific tolerances which is especially important given concerns with sealing, and manual pumps are inexpensive anyway. Our final design is a good compromise between recycling components, functionality, and cost.
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
We scaled back our flowrate goal as our initial estimate of 13 GPM was probably more than necessary for an average village and not practically possible. Instead of focusing on horizontal distances, we instead used vertical distances as our metric for pressure due to the impracticality of testing over long distances. We were successfully able to pump 2 GPM up to 13.5 m. Our model indicates that with a ¾” diameter pipe about 15-‐20% of pump head is lost to frictional losses (depending of course on flowrate). Conservatively estimating that 15% of our pump head was lost to friction, 13.5 m of vertical head would give a total pump head of 15.8 m. As such, we accomplished just under our revised goal of 3 GPM and a little bit above our revised goal of 15 m of pump head. It is likely that we could have hit the 3 GPM at 15 m metric had we tested our system with a greater power input. Many qualitative goals were added into the project between the beginning of the year and now including: portability, usability, ability to use any bike, and ease of set up. We feel that we have met or exceeded all of these qualitative goals as discussed in detail in the previous sections. In terms of cost, should our product be manufactured at scale and with the stand made from scrap metal instead of purchased, it could certainly be manufactured for around $100. The bulk of the cost is due to the pump ($66) and the generator ($40). The addition of the generator, which was not part of the design with the initial $20-‐100 cost estimate, adds a lot of value to our product even though it is a major cost driver.
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MECHANICAL ENGINEERING DESIGN PROJECTS FINAL STATUS REPORT
COST In terms of literal expenses throughout the entire year, we spent $814.84, which is $81.16 under our allotted $900 budget. However in terms of what we spent that was actually used in our final project, it comes out to be significantly cheaper. The actual cost of everything that was used in our final product was $448. The tubing was a large part of this cost at $180. The generator, pump, and stand amounted to $177. The extra $41 came from miscellaneous expenses like screws, bungee cords, nuts, a check valve, and hose connectors. We also had to buy a bike, however we bought a used one at Neighborhood Bike Works for only $50. The discrepancy between the product cost and the total cost of $914.84 comes from expenses not directly toward the final product, such as costs associated with prototyping, development, and testing equipment. The costs associated with prototyping and development were for items that were ordered but ended up not needing due to design changes. Our first pump, which was made of cast iron, rusted and was too heavy, so we ordered a second, plastic pump which was used in our final design. We also ordered two generators because we were unsure which model would work best and wanted to avoid delays due to ordering a second generator. We only ended up using one, however. Miscellaneous items ordered from McMaster in the beginning of the year when we wanted to make the pump ourselves amounted to another $150. About $40 was spent on accessories for the bike such as a 12 Volt battery and a bike light. Both were ordered to demonstrate what the bike was capable of accomplishing. The remainder of the costs resulted from testing. A check valve, a gate valve, a pressure gauge, and smaller amounts of tubing were purchased for testing. Things like thread sealant, latex tape, various types of hose connectors, and thread connectors were also used for testing. We really used these items primarily in testing, so they were a necessary cost, but didn’t actually go into the final product. This combined with smaller expenses like tape, spray paint, and glue made up for the rest of the expenses.
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Summary of Expenses Items Ordered Through the Business Office Cost RAD Cycle Products Indoor Portable Work Out Bicycle Trainer $75.18 Cast Iron Rotary Drum Pump, 10 GPM $43.95 Plastic Rotary Polypropylene Drum Pump For Chemicals # 4649-‐99 $66.10 Small Alternator, Mini Generator $36.50 Small Alternator, Mini Generator for Wind Turbine $49.00 EPDM O-‐Ring AS568A Dash Number 242, packs of 10 $6.29 Sheet Gasket Assortment Includes 14 Sheets, 6" X 6" $24.26 High-‐Strength Adhesive/Sealant Marine, 10.2-‐Ounce Cartridge, Clear $9.74 Zinc-‐Plated Steel Bolts with Two Hex Nuts and Washers $9.33 Machine Screw Hex Nuts, Zinc-‐Plated Steel $1.21 3/4" Air and Water Hose, Black Hose $17.70 Two Male Fittings for 3/4" Air and Water Hose, Black Hose $16.24 Business Office Total $355.50 Reimbursements Home Depot $46.00 Bike and Parts $60.00 Lowes Mar 24 $34.39 Home Depot Mar 31 $9.66 Bike Church Mar 28 $5.00 Radioshack Mar 29 $25.89 Lowes Mar 31 $198.22 Dr. Jackson Hardware Store, Swing Check Valve $11.76 Monarch Hardware $12.13 CVS Pharmacy $4.85 CVS Pharmacy $4.85 Radioshack Apr 6 $4.53 Radioshack Apr 9 $5.92 Hardware Store Apr 10 $4.96 Hardware Store Apr 11 $6.47 Lowes April 8 (Alyssa) $26.04 Home Depot Apr 8 (Alyssa) $2.67 Reimbursement Total $463.34 Sum of Expenses $818.84 Total Budget $900.00 Difference -‐81.16 15 | P a g e