Group 4 - Lawn Mower Engine

Group Members

• Sean Lyons - Project Manager: - Set goals for each meeting and see that they are accomplished. - Divide work among each member each meeting. - Manage meeting work time

• Jessie Allen - Communication Liaison: - Email members meeting times and goals. - Organize group work into reports.

• Bhushan Karayilthekkoot - Solid Modeling Expert: - Perform solid modeling tasks.

• Tom Schuler - Wiki Expert: - Publish group work to the internet on our wiki page and manage it.

• Bob Belko - Deconstructing/Constructing Expert: - In charge of Deconstructing/Constructing the lawn mower engine.

Initial Product Assessment

3.1 Initial Product Assessment

(A)

(B)

Fig 1: (A) The top of the lawn mower engine; & (B) the same engine at a different view

3.1.1 Intended Use of the Product • Our group project is a 5 Horsepower lawn mower. This mower could either be for a push mower or a riding lawn mower. Whichever the case may be, it is intended for home use. This is shown by the small amount of power driven by the motor – if the Horsepower was higher, then there would be a more likely chance that this mower would be use for commercial use. • The main function of this motor is to successfully spin the blade attached to the shaft of the motor to cut the grass. Other pieces in this motor, however, have specific jobs. For example, the sparkplug starts the whole working process up, while the fan provides central cooling to the motor to prevent overheating while performing tasks. There are also other miscellaneous parts in the motor that have designated tasks that we will analyze once dissection of the motor has begun.

3.1.2 How do you think the product works? • There are three main types of energy that are used and consumed within the workings of this lawn mower. The first type is mechanical energy. This is present in the turning of the shaft and blade. This is also present in the rip cord that the user pulls to start the motor up (to get the motor running). Chemical energy is used in the process of combustion. We investigated what type of gas this motor takes, and this is unleaded gas – so this contributes to the chemical process. Thermal energy is also produced by simply running the motor. The motor will get hot after running for an extended amount of time, and thus why there is a fan system in place to expel this thermal energy. 3.1.3 Is the product currently functioning? • From our groups’ initial analysis, we have gathered that our lawn mower motor seems to be in good working order. We concluded this by first shaking the motor a bit to see if we could hear any loose mechanisms within the motor, but we did not. Also, we pulled the rip cord numerous times to see if we could hear the compression system working at its fullest. From our outside conclusions, we can predict that this is also in working order.

3.1.4 How complex is the product? • In terms of complexity of motors, this lawn mower is on the lower end of the spectrum for complexity. With a comparison to a car motor, this lawn mower is significantly smaller and has a much smaller amount of parts to deal with in terms of dissection. For the lawn mower, there a hard plastic outer shell, the main motor, a cylinder, sparkplug, numerous nails, and also possibly an air cleaner. Again, this is merely an outside perspective on what is included for this motor. Once we begin dissection, there will clearly be more parts that we will be concerned with. • Overall, these components named above are not very complex, from an initial outside analysis. The most complex part in the whole system would clearly be the motor itself. This will have little parts included with it (such as small nails), along with larger parts – such as a carburetor and exhaust system. This, overall, will be our biggest challenge when we start to dissect our product. 3.1.5 What materials are used in the product? • There are a good number of materials that our group could see from the outside of our product during our initial assessment. There is a hard plastic outer shell covering the whole product. There are numerous amounts of metal nails holding the lawn mower together. There is a rip cord located on the side of the product. Also, on the side of the mower, there is a visible spark plug jutting out. On the bottom of the product, there appears to be some kind of air cleaner or exhaust system. • There are also many more parts located inside of the mower that our group can guess are present. There are one to two cylinders present, along with a fan to keep the motor cool enough to run. There will be wires to connect the different parts together to perform the needed function. There must be a carburetor located inside for the said exhaust system. All of these parts are not known to be in the motor, but are crucial to the correct working

3.1.6 If you had to use this product, would you be happy with it? • Our group concluded that this product would be fairly comfortable to use. Since this product is fairly small, it would be easy to store anywhere, given its size. Also, the product is lightweight – anyone would be able to pick it up and move it around with ease. This motor would also fit into the designated lawn mower very easily given the two above factors. • This motor would also be easy to use as well. The gas tank is located on top of the apparatus – so this is easy to get to and maintain. Located next to this is the oil reservoir – this is also easy to access when needed. These two things together makes the maintenance of the product much more easier and less labor-oriented. • Continuing on maintenance, this product does require some basic upkeep. The user would need to change to oil every so often. Also, just like a car, this motor runs on gas and needs to be refilled when the gas runs out. When the change of season comes around, these liquids would need to be drained out to prevent freezing and bursting of the tubes that these liquids flow through. If the machine does require additional maintenance, this motor looks like it would be easy to disassemble – so the user could possibly fix the problem on ones’ own.

3.1.7 What alternatives to your product are there? • First we will compare our motor to an electrical motor. The advantage to our motor is that we do not need to electrically charge ours to make it fully functional. With electric motors, the product would need to be plugged into an outlet to make it fully operative. This also uses up a good amount of electrical energy, so it is not really an energy – safe, “green” method. • Next in comparison, we have just a crank, human-powered motor. Out of all of these listed alternatives, this is the least feasible in terms of productivity. This would take a significant amount of more time to get the task done than using our motor. Granted, this human powered method does not use up any energy machine wise, but this advantage does not outweigh the productivity factor. • Lastly, we have in comparison a battery powered motor. Depending on what type of battery is used within this motor, the user may need to electrically charge it to get the mechanism to work, just like the electric motor. If the battery does not need to be charged, then this motor works like our product – it can run with no outside energy added. The only downside to this is that the battery will, in fact, run out at some point, so the user will need to go get a new battery when this occurs. • Compared to other mechanically powered motors like ours, our motor has one advantage. Our gas and oil tanks are located on the top of the product. Other push (or riding) lawn mowers have the gas and oil tanks located on the bottom of the apparatus. This makes maintenance that much harder to work on, and possibly making these mowers less favorable. • Unfortunately, at this time, we are unable to compare prices for other motors/lawn mowers compared to ours. This is due to the fact that are not able to determine what company makes our mower, and also that we do not know whether this is a push mower or a riding lawn mower.

Management Proposal

Our group plans on a regular basis with specific objectives in mind each meeting. We plan to meet Mondays and Wednesdays, after class lecture at 5:00PM, in the project lab (Furnas 621). If needed, we will also meet on Thursdays in this same location at 3:30PM to finish what was not completed at the previous meetings. We can be contacted about our progress through the group manager’s email, sblyons@buffalo.edu. The group positions are as follows: Sean Lyons is the Project Manager, Jessie Allen is the Communication Liaison, Bhushan Karayilthekkoot is the Solid Modeling Expert, and Tom Schuler is the Wiki Expert. A table of our intended work timeline and position responsibilities outline are given below:

Along with these individual group tasks, each member is expected to contribute to the project write-ups as a whole to distribute work fairly and evenly.

Meeting Date..............Goals

10/12--------------------------Product Dissection

10/14--------------------------Product Dissection

10/19--------------------------Product Dissection

10/21--------------------------Product Dissection

10/26--------------------------Product Dissection

10/28--------------------------Product Dissection Write-up

11/2----------------------------Component Summary

11/4----------------------------Design Revisions

11/9----------------------------Solid Modeled Assembly

11/11--------------------------Engineering Analysis

11/16--------------------------Coordination Review

11/18--------------------------Coordination Review

11/23--------------------------Coordination Review

11/25--------------------------Coordination Review

11/30--------------------------Product Reassembly

12/2----------------------------Product Reassembly

12/7----------------------------Final Report

12/9----------------------------Final Report

Work Proposal

After the group’s first assessment of the lawn mower engine, we believe that disassembly process should run fairly smoothly. Judging from the mower engine’s external condition and the ability to hear compression in the engine, we concluded the engine is most likely fully functional. We estimate that the engine disassembly process should take between one to two hours. This is merely an estimate. Any unexpected discrepancies with the engine disassembly could possibly delay completion of dissection. This would include, but not limited to, remembering where all of the littler parts for the motor itself go. Evaluating the machine from the outside and using the group’s knowledge of small internal combustion engines, we compiled a list of tools that will be required for the dissection process. Tools not on the list may be needed once the dissection begins and/or during reassembly.

Tool list:

1. Phillips head screwdriver

2. flat head screwdriver

3. standard wrench set

4. spark plug socket

5. standard socket set

6. needle nose pliers

7. pliers

8. standard Allen wrench set

9. piston ring puller

10. rubber mallet

As a group, we are confident that our combined experiences and abilities will be able to effectively dismantle the lawn mower engine. All the members of the group have great leadership skills and work well together. We have specialist in 3-D modeling. It is apparent that most of the group has a basic knowledge of small internal combustion engines. One challenge that we feel the group will have to overcome is the use of the wiki page. The group members lack experience with wiki webpage development.

Disassembly approach:

1. Remove gas tank

2. Remove carburetor assembly

3. Remove starter assembly

4. Remove cylinder head

5. Remove crank case cover

6. Remove cam shaft assembly

7. Remove valves

8. Remove piston

9. Remove piston rings

While removing components, our group will be cataloging and taking pictures of every component to reinsure easy reassembly, and also measuring these said components to make realistic drawings in CAD modeling..