Product Archaeology: Product Explanation

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Introduction

The major step in this gate is to reassemble the generator. We will take the information we have learned through this process to draw conclusions on the product. We looked into how we could have planned the reassembly better or dealt with challenges associated with it in a more efficient way. We reassembled the product and took specific notes on every step. As a group we also devised three revisions on a system level that we feel would greatly improve the product.

Product Reassembly

How Assembly Differed from Disassembly

The assembly was the same as the disassembly in many ways. For the most part, the assembly was basically a reverse process of the disassembly. This being said, there were several differences, which are listed below.

• Pressing vs. Removal. The removal of pressed on components was a difficult process without a wheel press. It requires quite a bit of even force to accomplish this task. Pressing the component back into place in the assembly process was much easier. The only thing required was to tighten a threaded fixture with a little force.
• Compression of Springs vs. Removal. There were compressed springs in the overhead valve. Removing these springs required about a quarter inch of compression followed by a small shift to one side to remove. This is a fairly easy process. Compressing the springs back into place requires a lot of controlled force, while holding the valves into place. This is a very difficult process in which force and control are required to properly position the head of the spring.
• Compression of Piston Rings vs. Removal. The piston head slides easily out of the combustion chamber without any force or special removal process. In order to slide the piston head back into the combustion chamber, either a piston ring compressor or a thin sheet of metal could be used. The compressor or sheet metal would guide the rings tightly into the combustion chamber.
• Cleanliness of Disassembly vs. Assembly. During the disassembly process, oil was present within the oil reservoir. This proved to be a messy process when the engine block was separated. Also many of the components were greasy and oily. Due to the fact that most of the parts were wiped off during disassembly, the assembly process was much cleaner.
• Knowledge of Needed Tools/Information for Disassembly vs. Assembly. When disassembling the generator, the group did not have knowledge of how to accomplish certain steps and what tools to use, whereas the assembly process went much smoother.

How was Product Originally Assembled

When determining how the generator was originally assembled, certain things are taken into account. This includes manufacturing, outsourcing, assembly type, and preassembly. When Honeywell makes the decision to use Honda engines to make their generator work, the entire engine should be outsourced to Honda in Japan. The engines will most likely come to Honeywell preassembled. Many other parts are most likely outsourced to other companies before the end product is finished. The process Honeywell takes after receiving these parts is to determine if any manufacturing needs to be done, such as molding the power center panel. Once all of the components and/or subsystems are present and ready for assembly, they are sent down an assembly line of either working men or automated machines or both. A simplified process is listed below.

• Outsource components and subsystems from other manufacturers.
• Evaluate what manufacturing processes need to be completed to acquire all components.
• Make these components.
• Assemble subsystems using labor or automation.
• Assemble system through connection of subsystems using an assembly line of labor or automation.

Original Tools used for Assembly-

• Metric Sockets and Wrench: Since all the nuts and bolts on the generator were of metric size, it makes sense that in the original assembly metric sockets were used.
• #1 and #2 Phillips and Flat head Screwdrivers: Various screws were present in the generator system.
• Bearing Press: A bearing press was probably used to insert the bearings onto the camshaft and the engine block.
• Piston Ring Tool: This special tool is used to compress rings onto the piston.
• Various: other various tools, seeing as how we can only speculate as to what tools were used for the original assembly, some tools may differ to the ones we used for the assembly.

Scale Explanation

In the reassembly of our generator, we devised a scale to help rate the difficulty of each step of the reassembly step. The scale uses the basic 1 through 10 ranking system where 10 is the harder reassembly step and 1 is the easier reassembly step. We have created a scale that is based off of four main criteria: Time, Force, Tools Used, and Accessibility. Each of the four criteria are allotted 2.5 usable points that when all added together determine the final difficulty of reassembly. The more intricate a criteria the more points a reassembly step will be awarded. When assigning the point value to each criteria for a specific reassembly step, we thought about the following variables for each:

I. Time - When assigning a point value to a reassembly step for the time variable, we took into consideration the amount of time spent on planning, devising, and actual hands on reassembling. The total amount of points that can be given for the Time criteria is 2.5

II. Force – When assigning a point value to a reassembly step for the force variable, we took into consideration the amount of force required and the precision of the force. The total amount of points that can be given to a reassembly step based on the Force criteria is 2.5

III. Tools – When assigning a point value to a reassembly step for the tools variable we took into consideration the amount of tools needed, the complexity of the used tools, and if there was a need for simultaneous tool usage. The total amount of points that can be given to a reassembly process based on the Tools criteria is 2.5

IV. Accessibility - When assigning a point value to a reassembly step for the Accessibility variable, we took into consideration the awkwardness in position of the process, and the amount of people needed to reassemble. The total amount of points that can be given to a reassembly process based on the Accessibility criteria is 2.5

After we assigned each reassembly step individual scores based on the criteria above, we added each of the four criteria scores and were left with a final difficulty score. Outlined below are the steps of reassembly with their respective difficulty ratings.

Stage 1 - Core Components

Introduction

The first stage of the reassembly process consisted of the subsystems that made up for the majority of the functionality of the generator. These subsystems are:

I. Engine

II. Electric Generator

III. Overhead Valve

We not only reassembled these subsystem first because of working in reverse order, but because they were also the most important. Without these subsystems there us no possible way for use to achieve a product remotely close to a generator. All of these subsystems are linked by the fact that all of their functions make up the working of a generator. Below are the steps of reassembly for this stage.

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Table 1: Stage 1 of Reassebly

Stage 2 - Secondary Components

Introduction

For stage 2 of the Product disassembly we chose to reassemble the following subsystems:

I. Carburetor

II. Pull Start

III. Electric Start

IV. Throttle

V. ½ of the Frame

We chose to reassemble these subsystems second because of their respective functions. All of these subsystems are not necessarily crucial to the running of the generator, but they link and start the functions of the other subsystems. Below are the steps of reassembly.

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Table 2: Stage 2 of Reassebly

Stage 3 - Finish Components

Introduction

The following subsystems make up the final stage of the reassembly.

I. Gas Tank

II. Muffler

III. Carbon Canister

IV. Power Center

V. Air Filter

VI. ½ of the Frame

We chose to reassemble these steps last because of their related functions. All of these subsystems aid in the final running of the Generator. Weather it be from an ergonomic or supply standpoint, all of these subsystems are linked by the fact that their functions complete the generator. The Steps of the reassembly are listed below.

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Table 3: Stage 3 of Reassebly

Challenges Faced

As a group we faced challenges during the reassembly process. The gate was scheduled to be completed during thanksgiving break, which proved to be not realistic as members could not correlate free time and one member went out of town for break. So the entire gate got pushed back into a single week. Whether or not it was poor planning, this was a great deal of work to accomplish in a short period of time. To make matters worse, the only place we saw suitable for working on the generator was a member’s workshop in Orchard Park. During this week of scheduled work, the weather was horrible to the point where thru ways were closed and there was no way to get to or from the shop. So the reassembly had to get crammed into 2 days, cutting close to the deadline. Overall the assignment was completed on time, and the only real challenges faced were actually getting manpower to our generator. The reassembly itself went very smooth, much smoother than we anticipated, based on the difficulty of disassembly.

Design Revisions

Introduction of Design Revisions

Below are listed three design revisions that we see fit to improve our product. We looked into altering the power center, fuel source and function of the engine, converting from 4-stroke to 2-stroke. We believe these changes will improve the products performance, serviceability or usability. These changes also target one or more of the 4 factors of design, global, societal, economic or environmental.

Propane vs. Gasoline

I. Problem Addressed –If there is no available gasoline or if propane is a more readily available fossil fuel, then a propane-powered generator would be more advantageous. Gasoline does not have a good shelf life, only 6 months. Most building codes require that no more than 25 gallons of gasoline can be stored in a residential area. This amount of fuel would only last 25-30 hours and in some emergency situations that will not suffice. Most fuel pumps require electricity, so the user may not be able to acquire more gasoline.

II. Proposed Solution –The solution to this problem is to equip the generator with a propane adapter that attaches to the carburetor and allows a propane mixture to flow rather than a gasoline mixture. Propane has an unlimited shelf life, much better than that of gasoline. Propane can be stored in large tanks, unlike gasoline. A larger tank means more fuel, which directly impacts the allowable runtime. It is the only fuel source that does not require electricity to refill. This is a huge advantage in a wide spread blackout.

Figure 48:Photo from www.propane-generators.com. Shows an installed propane adapter between the carburetor on the left and air filter on the right.

III. Directly Affected Subsystems

A. Carburetor Subsystem –The adapter will attach to the carburetor, and allow for a propane mixture to be burned, not a gasoline mixture.

B. Air Filter Subsystem –The air filter will need to be moved in order to make room for the adapter. Thus longer hoses will be needed for the connection between the carburetor and the filter.

IV. Improvements

A. Allows for an Alternative Fuel Source –With this adapter, the use of propane or natural gas is permitted. This is a huge advantage in situations where gasoline Is not available.

B. Propane or Natural Gas Burns Cleaner –Propane or Natural Gas burns cleaner in the engine and will not “gunk” up the carburetor or engine.

V. Revision Tradeoff’s

A. Propane is More Expensive – In an emergency when a generator is used, the user is often desperate for electricity so the higher cost for propane is not as important as the need for power. The potential disaster for a homeowner, such as a sump pump failing, will outweigh the minor cost increase of propane to gasoline. Also during an outage, people are desperate for gasoline and as gas stations get swamped with people hoarding fuel, the price goes up as well as rationing. Thus propane may even be cheaper during an outage, when a generator is used.

B. Propane Will Not Supply the Amount of Power Gasoline Would – The adapter is equipped with a different venturi than the gasoline venturi in the carburetor. So the propane adapter will allow for the necessary amount of propane to enter the piston to output the same amount of power that the gasoline would have.

C. Once the Adapter is Attached, Gasoline Cannot Be Used Anymore – This is False. The Adapter is specifically an adapter, not a converter. Thus the adapter will not inhibit any process that was used prior to the adapter being installed.

VI. Four Factors

A. Economic –The adapter can either be sold as a separate attachment or packaged with the generator, depending on the manufacturer’s decision. If it is sold with the product it can be promoted as a major alternative and can be sold for a higher price. Or it can be sold separately for a cost determined by the manufacturer.

B. Global –Propane and natural gas are available worldwide so the product could be marketed overseas. Different connections and or hoses could be sold separately as needed.

C. Societal –The issue of propane leaks will increase the necessary safety for the generator.

D. Environmental – N/A

Power Center Upgrade

I. Problem Addressed –Limited outlets for consumer use.

II. Proposed Solution –2-4 more outlets available

III. Directly Affected Subsystems

A. Generator Subsystem –The generator must output a larger current for an even voltage at 120 V. Either more coils would be needed or the shaft would have to rotate faster to generate the proper amount of Voltage.

B. Engine Subsystem –Due to the requirements needed by the generator, the engine would have to output more power. This means that the engine would need to either rotate at a faster speed or a gear arrangement could rotate the generator shaft faster.

IV. Improvements

A. Improvement 1 –2-4 more outlets available for consumer use

B. Improvement 2 –Increase the rotation rate of the crank shaft.

V. Revision Tradeoff’s

A. Tradeoff 1 –2-4 more outlets-More power necessary to accomplish this task. More outlets are convenient during a power outage providing expanded use. Manufacturing of different power center panel will increase cost. Cost of extra outlets. Electric Hazard increased with more outlets.

B. Tradeoff 2 –Increase rotation of crank shaft. Fuel consumption increased. Possible increase of vibration. Noise increase. More exhaust pollution

VI. Four Factors

A. Economic –Consumer will spend more on fuel. Cost of extra outlets minimal. Change in power center manufacturing to fit in extra outlets.

B. Global –N/A

C. Societal –Consumer is more satisfied with more outlets to use at their discretion. Decision may be swayed by increased gas consumption. Larger span of outlets provide for more possibilities of electric hazard. Possible increase of vibration, noisy.

D. Environmental –Fuel consumption wasteful. More exhaust pollution.

Two Stroke vs. Four Stroke Engine

I. Problem Addressed – The generator is too expensive for people in the lower classes of society.

II. Proposed Solution – Replace the generators four stroke engine with a two stroke engine to decrease the complexity of the engine; therefore decreasing the manufacturing costs and in turn the price of the generator

III. Directly Affected Subsystems

A. Engine Subsystem – Because the two stroke engine fires once every revolution instead of once every other revolution, the engine will generate more power.

B. Generator Subsystem – The engine would produce more power, which in turn will cause the generator to produce a higher voltage output.

IV. Improvements

A. Complexity – By switching to a two stroke engine, the complexity of the engine decreases. With two stroke engines there are no valves, therefore simplifying their construction and lower production costs.

B. More Power – A two stroke engine fires twice as often as a four stroke engine; generating significantly more power.

C. Lighter – Because of the simpler design, the engine also weighs less and is easier to transport.

V. Revision Tradeoff’s

A. More Pollution – Because there is no exhaust on a two stroke engine, more pollution is released from the engine than with a four stroke engine. Also, each time a new mix of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port.

B. Shorter Life – The lack of an exclusively allocated lubrication system means that the parts within the two stroke engine wear out faster. Two stroke engines require a mix of oil in with the gas to lubricate the crankshaft, connecting rod and cylinder walls.

C. Does not use Gas Effectively – Since the two stroke engine fires more often it is less fuel efficient than the four stroke engine.

VI. Four Factors

A. Economic – There will be a decrease in manufacturing costs and also in the price of the product allowing it to be marketed to a wider variety of consumers. There are also less parts in a two stroke engine which leaves fewer parts to break, and fewer repairs.

B. Global – N/A

C. Societal – Consumers will have to mix the oil and gasoline before fueling the engine, if this is not done properly the engine could malfunction, because of this more instructions must be given to the consumer to ensure their safety and the liability of the company.

D. Environmental – The two stroke engine will effect the environment because it will emit more pollutants into the air because of the lack of exhaust in a two stroke engine.

Figure 49:Two Stroke Engine Process