Group 12/RFP
Contents |
Purpose
Image courtesy www.gaspoweredleafblower.net
Introduction to Mechanical Engineering (MAE277) at SUNY Buffalo was divided into groups. Each group has the same assignment with different products. We will form a project design team that will take one product, disassemble it, investigate various aspects of its design and manufacturing and reassemble the product to its original condition. These products include automatic transmissions, internal combustion engines, pumps, computer components, consumer products, small kitchen appliances, and power tools and many others. Our group was assigned a leaf blower. We are group twelve and members are: Michael Ciambella, James Cendrowski, Patrick Daigler, Matthew Blasz, and Marie Catalano.
Work Proposal
-First step of disassembly is to take apart the outer plastic housing which encloses the main system of the leaf blower. The main system of the leaf blower consists of the motor, fuel and ignition systems, blower fan, and muffler. The removal of the outer shell will include the disassembly of handle, protective guards, and air tube. The first step will require a set of metric Allen wrenches as well as a set of Phillips and flathead screwdrivers. The procedure will take an estimated thirty minutes.
-Second step of disassembly will involve removing main external components of the motor. These external components include the impeller and impeller housing, carburetor, muffler, and fuel tank. The second step will require previous tools, as well as a set of metric sockets. A can of penetrating oil may also prove helpful. The procedure will take an estimated forty-five minutes.
-Third step involves the disassembly of the engine. This will include removal of the cylinder head, separation of cylinder from the crankcase, and removal of the crankshaft assembly, complete with connecting rod and piston. The third step will require previous tools, as well as a set of metric wrenches. The procedure will take an estimated sixty minutes.
Fourth and final step of disassembly will include the exposure of the internal workings of the carburetor.The fourth step will require previous tools. The procedure will take an estimated fifteen minutes. Since another group was assigned with disassembling the motor, the group decided to not disassemble the bearings or any part that is pressure fit together. The gain in information in disassembling these parts is outweighed by the amount of work needed to take them apart.
Time Management
Time Management is a key ingrident to success in any group project. To stay on track we have set deadlines for each part of the project. Table 1 is a layout of due dates of projects and sub-projects, and when we should have them completed.
Our group plans to meet every Wednesday 5-7 PM in Furnas 621 and every Friday 3-4 PM in Bell Computer Lab, unless otherwise specified. The group encountered a conflict with the meeting time on Wednesday, the group member had an extracurricular sport that was at the same time. Since this group member was not able to make the meetings, his assignment load was increased. As a group we worked out each problem beforehand so that the assignment was only typing up the information.
Group Assesment
Group 12 works very well together. For randomly assigning 5 students in a class to work together on a project we work well together. Usually we meet to discuss the assignment and draw out a rough draft of the main concepts we wish to become the spine in our report. Everyone goes home with a part of the report assigned to them. When it is complete they e-mail it to Michael who proofreads and formats it. Michael then sends it to Marie to be uploaded to the webpage.
The main strength of our group is recognizing strengths. We know which members are skilled in certain areas and we are utilizing them in their specific area. All of the strengths of the individuals create a well balanced, high functioning team. The main weakness of our group is scheduling. With five incredibly busy engineering students, finding time where everyone is free to work on the project for an extended period of time is difficult.
The capabilities of our group are endless. We are a strong, determined group. Between us we have the extensive knowledge of how engines operate, Autodesk Inventor, and the creation of a webpage. We are eager to learn more about the engine and ready to take on the task. Some shortcomings our group may face would be staying on task, and in turn running out of time. Hopefully we follow the Grantt Chart and complete what we had scheduled on time.
The strengths and weaknesses of each group member areas follows:
| Name | Strengths | Weaknesses |
|---|---|---|
| Michael Ciambella | Organized Punctual Strong leader |
Minimal knowledge of engines |
| James Cendrowski | Strong writer Familiar with 3-D modeling |
Commmunication skills |
| Matthew Blasz | Extensive knowledge of engines Familiar with tools required for disassembly Strong technical writer |
Unfamiliar with computer modeling software |
| Patrick Daigler | Experience with snowmobile engines Deep understanding of mechanical processes |
Procrasinator Communication |
| Marie Catalano | Organized Communication |
Unfamiliar with engines Unfamiliar with tools and disection process |
Management Proposal
To work more efficiently, each member of the group has been assigned a title with specific tasks of what that title entails.
| Group Member | Job Titlte | Tasks |
|---|---|---|
| Michael Ciambella | Project Manager | Coordinate Group Meetings Act as the point of contact Keep group on task Be aware of and enforce deadlines Organize reports |
| James Cendrowski | 3-D Model Specialist | Aquire Autodesk Inventor Learn how to use Autodesk Inventor Produce a 3-D model of the engine before the deadline |
| Matthew Blasz | Technical Expert | Apply deep knowledge of engines and mechanics Aquire tools for dissasembly Disassamble the engine |
| Patrick Daigler | Technical Expert | Apply deep knowledge of engines and mechanics Analyze how the product works Reassemble the engine Assist in writing up reports |
| Marie Catalano | Wikipedia Expert | Record what was discussed in meetings Take pictures of disassembly for documentation Learn how to create a Wikipedia page Post assignments, pictures and videos on the page |
Inititial Product Assesment
The intended use of the product is to displace leaves and miscellaneous yard refuse. With just a preliminary judgment, considering the materials and off-brand name, it is rather obvious that this product is intended for home use. Although designed and built for residential use, the product could be used for light commercial operations, such as a small lawn care business. In addition to being a leaf blower, various markings claim that this product doubles as a vacuum as well as a blower. Although it is unknown how this conversion takes place as of yet, one can deduce that it would not be a very complicated process (the machine was intended to be used by the everyday person).
Based on the experience within in our group, it was rather easy to determine how this product works. Basically, the leaf blower contains a two-cycle gasoline engine that turns a blade, causing air to be forced through a specially designed nozzle that protrudes about two feet from the motor. The fan blade is attached directly to the vertical shaft motor, and draws air from an opening in the bottom of the blower. Plastic cowlings channel the air into the nozzle and also provide a basis for the main body of the blower itself. Different types of energy that are utilized in the leaf blower are as follows:
• chemical energy: in the form of gasoline that is used for combustion
• thermal and mechanical energy: from the conversion of gasoline
• electrical energy: utilized to create a spark required to ignite the gasoline
• mechanical engery: converted to electric potential by a magneto and is discharged to create a spark
• thermal energy: a biproduct of combustion but it is also used to keep the engine at optimally warm operating temperatures
• chemical energy: after it is converted into mechanical energy, it is transfered through a shaft to the main moving part, the fan blade
• kinetic and potential: considered in the function of the fan blade; there are moving parts in both the engine and fan, which are considered kinetic energy, where as potential exists in the gasoline and electrical systems
Functionality and Complexity
The leaf blower was removed from the lab and tested in the parking lot. After being filled with 40:1 two-cycle engine fuel, the engine was primed. After a half dozen attempts to pull start the engine, ether (more commonly known as starting fluid) was sprayed into the air intake in an attempt to get the engine to fire. Despite further attempts at pull starting the engine, it was determined that the engine did not run. However, it was clear that the engine had compression, as evidenced by the force required to turn the engine over, and the air passing through the exhaust.
Due to the fact that the engine came from a mechanics shop that believed it was not worth fixing, it was no surprise that the engine did not run. For any gasoline engine to run, three basic components are necessary: air, fuel, and spark. Although the exact reason that the leaf blower did not run is unknown at this time, logic can narrow the cause down. First and most likely, is the absence of spark in the combustion chamber. After putting either into the engine, if spark was present, odds are that the engine would have at least puttered. However, a lack of the proper tools prevented the removal of the air filter, making it plausible that the ether was not fully sucked into the engine (if either the air filter was clogged). Furthermore, upon inspection, the fuel filter seemed rather dirty, as did the gas tank. It is completely possible that the carburetor jets are clogged, thereby not allowing fuel to enter the chamber. Lastly, the engine may just be worn out and unable to create enough suction and compression necessary for operation. Just because compression is present, as evidenced in the test, no formal compression test was performed, leaving the possibility of a worn engine.
Complexity can be rated through multiple characteristics, such as the number of tools required to assemble, the time required to assemble, having more than three multi-component subsystems, and the number of sub functions it has. The leaf blower would be more complex than a flash light because it requires more tools to assemble. On the other side, a motorbike would be more complex than a leaf blower because it has more multi-component, and it would require more time to assemble. However, based on one’s definition of a system or component, the argument could be made that a flashlight and a leaf blower could be of equal complexity (i.e. having the same number of components). It seems as though there is no concrete definition of “complexity”, but rather a blend of many factors.
The leaf blower is a rather complex based on our definition of complexity. There are many components that make up the product. Not all of them are visible making it difficult to get an exact number of the components used. Based on our observations there are six components that are visible from the outside. They are the hard plastic shell, the blower nozzle, the handle, the intake vent, the control levers, and the rip cord. We can assume that on the inside there is a fan, engine, carburetor, muffler, spark plug, air filter, and a fuel tank. The complexity of the components deviates greatly from the simple rip cord to the complex engine.
Listed in the table below are all of the components that make up the leaf blower, the materials they are likely made out of and if they are visible without taking disction or not. If they are not visible without disection we could get hints through small cracks in the exterior and educated guesses.
| Component | Probable Material | Visiblity
|
|---|---|---|
| Outside Plastic Shell | Polypropylene | Visible |
| Nozzle | Polypropylene | Visible |
| Screws | Stainless Steel | Visible |
| Rip Cord Handle | Smooth Plastic | Visible |
| Rip Cord | Nylon | Visible |
| Spark Plug Insulator | Polyethylene | Visible |
| Interior Metalwork | Cast Aluminum | Not Visible |
| Fuel Tank | Polypropylne | Not Visible |
| Rubber Seals | Polyethylene | Not Visible |
| Electrical Wires | Copper | Not Visible |
Due to lack of experience with leaf blowers we are not sure of the satisfaction with this product. We have nothing to base our satisfaction off of. We believe the product has a lot of potential. Depending on the consumer comfort with the product will could vary dramatically. Some problems with the product could be that it is too small for their task, the consumer could be scared to use gasoline, or the product might be too heavy to carry.
For most people, this product will be easy to use. It is lightweight and portable. As for maintenance, minimal day to day maintenance is required. Besides checking the fuel/oil mixture before use, the only other main component that would require service is the air filter on the engine. The air filter should be checked and kept saturated with oil, as it is vital to the longevity of the engine. Over time, other maintainance might incude changing or regapping the spark pulg, and cleaing the carburetor jets. If the fuel filter becomes clogged or dirty, it must be replaced as it is unable to be cleaned. Overall maintenance is relatively low because the product is very durable.
Alternatives
Image courtesy ehow.com
There are a few alternatives to gas leaf blowers. One and probably the simplest, is a rake. A rake with a metal shaft, a plastic head and handle costs about fifteen to twenty dollars. The biggest difference between the two is how they are powered. Rakes do not need any electricity or gas to run. They are powered by the user. The disadvantage is, although lightweight, it is very time consuming to rake leafs, especially if one has a big yard.
The next alternative is a leaf sweeper. A leaf sweeper is like an old fashion powerless lawn mower, there are blades connected by two wheels that scoops leaves into a big bag. This product can cost around one hundred and sixty dollars or more. It is much more efficient than raking leaves, and it doesn’t need any resources like electricity or gas to power. The disadvantage of the leaf sweepers are there price.
Our last alternative is the electric leaf blower. It can cost around sixty dollars or more. It basically has identical functions to a gas blower, without the gas. The electric leaf blower uses electricity either from a battery or a chord plug in. If it is chorded, its mobility is limited. If it is battery operated, it has limited run time. All of these alternatives have common advantages over gas leaf blowers. Gas blowers have had countless complaints of air pollution and noise disruption. The air pollution problem is a double edged sword. The gas burning pollutes the air, but the blowing of leafs creates air pollution by blowing dirt into the air. Another advantage of these alternatives is cleaner burning emissions. Gas blowers waste gas because they are a gas-oil mixture. Electric leaf blowers offer a petroleum free emission.
