Product Archaeology: Product Evaluation

Return to Main Page

Return to Product Analysis Page

Component Summary

Introduction

The Part List

To improve professionalism, we have created an entire component list. We tried to mimic component lists that professionals assemble when they sell their product to consumers. When viewing the part list, keep in mind it is organized alphabetically by SUBSYSTEM. This will help should you need to find a specific component.

Each component has a specific “code name.” To improve the organization, each component code name begins with a letter that corresponds to their respective subsystems. For example, all the components within the engine subsystem will have a code name that begins with the letter “E”. And likewise, all components that are in the Electric Generator subsystem will have a code name that begins with an “EG”. After the subsystem letter, the rest of the code name letters will be an abbreviation of the actual name of the component. For Example, the engine block would start with “E” for engine, and end with a “B” for block. Combining these two, we have created a code name for the engine block that is “E–B”.

Not only does every component in the part list have a written description in the “info” link, but each component has its own picture under the “photo” link. Since most of the components are so complex, the info section of each component can be wordy or sometimes too complex to explain in words. Please use the visual aids to better comprehend each component.

Parts List

Subsystem photos

To clarify where all of the parts from the part list come from, we have assembled overall pictures of each subsystem. Please refer to these pictures when grading Gate 3 to help better understand where all of the components come from. The subsystem will be named on each image with a clear indication as to where it is on the image.

Figure 1: Frame Subsystem

Figure 2: Gas Tank Subsystem

Figure 3: Muffler Subsystem

Figure 4: Overhead Valve Subsystem

Figure 5: Power Center Subsystem

Figure 6: Pull Start Subsystem

Figure 7: Throttle Subsystem

Figure 8: Electric Start Subsystem

Figure 9: Engine Subsystem

Figure 10: Electric Generator Subsystem

Figure 11: Carburetor Subsystem

Figure 12: Carbon Canister Subsystem

Figure 13: Air Filter Subsystem

Product Analysis

Introduction

The eight components below were chosen for the product analysis. We felt that the characteristics of these components were noteworthy of analysis because of their shape, material, complexity and manufacturing methods.

ES-GH – Electric Starter Gear Housing

FUNCTION

I. Performed function(s) -

1. Transfers rotational motion to the engine fly wheel (E-FW) when starting the engine.

II. Flows -

1. Kinetic Energy-Rotational motion is transferred from the electric starter motor (ES-M) to the ES-GH and delivered to the E-FW.

2. Internal Energy-The gears are held in place by a spring, but when in motion, they slide forward creating potential energy.

III. Environment

1. Temperature- Ranges from hottest to coldest weather conditions.

2. Pressure-Atmospheric pressure

3. Chemicals-Atmospheric gases and greased up gears

FORM

I. Shape

1. Noticeable shape Properties- Housing is hollow and complex in shape, symmetrical in one plane along axis. Gears are round and symmetrical. Shaft is cylindrical and symmetrical.

2. Dimensions & Size-Housing LengthXWidthXHeight-9.5X8X6 cm, Shaft Length-10 cm, Shaft Diameters at L=0,2.5,4.5,6,7,8-1,4.5,3.5,1,2.5,1 cm, Gear 1 LengthXDiameter-1X4 cm, Gear 2 LengthXDiameter-1.5X2 cm, Housing Weight-4-5 g, Shaft Weight-10-12 g, Gear 1 Weight-6-8 g, Gear 2 Weight-2-4 g, 3D

3. How shape affects and contributes to function-Housing shape holds shaft into place and has openings for gear rotation. Shaft and gear shapes allow for proper rotation.

II. Material – (Stainless Steel)

1. Why it is made from (Stainless Steel) –Provides strong material for rotational torsion.

2. Alternative usable Material –Aluminum, iron

3. Outstanding Factors influencing the choice of material

A. Global

B. Societal

C. Environmental

D. Economic-Cheap and strong material

III. Aesthetics

1. Reason for Color – Natural steel gray

2. Purpose for look – Functionality, not in the open, not meant to be seen.

3. Surface Finish –No surface finish

MANUFACTURING METHODS

I. Suspected Method – Mold casting, Forming and shaping

1. Evidence for Suspected Method-Shape of housing limit options, Shaft and gears most likely manufactured by extrusion or drawing based on axial symmetry.

II. Limits on Manufacturing-

1. Limits from used Material- No limits

2. Limits from shape and geometry- Housing has many intricate features limiting the processes available.

III. Outstanding Factors for Manufacturing-

1. Global

2. Societal

3. Environmental

4. Economic-Cost effective molding and drawing

COMPLEXITY 1 – 10: 1= Simple 10 = Intricate

I. Scale Rating: 9

1. Criteria For Scale

A. Function-Just one major function to rotate E-FW when starting engine.

B. Form-Housing has many intricate features, such as an open window, boring, channels for gears, base assembly, mounting brackets. Many small pieces are included in the shaft and gears.

C. Manufacturing-Casting, drawing, drilling used.

II. Complexity of component within the respective subsystem –

1. Starter subsystem jumpstarts the engine for continual runtime. The ES-GH actually rotates the E-FW for kickstart motion.

2. Complexity Rating within its subsystem: 4

ES-M – Electric Starter Motor

FUNCTION

I. Performed function(s) –

1. When prompted by the power starter an electric current rotates the motor to rotate gears in the electric starter gear housing (ES-GH) to assist ignition motion on the engine fly wheel (E-FW) to start engine.

II. Flows -

1. Electric Current-Current is transferred from power center to rotate ES-M shaft.

2. Kinetic Energy-Rotational motion is transferred from ES-M shaft to gears within ES-GH.

III. Environment

1. Temperature-Ranges from hottest to coldest weather conditions

2. Pressure-Atmospheric pressures and torsional pressure from gears.

3. Chemicals-Atmospheric gases

FORM

I. Shape

1. Noticeable shape Properties- Casing is cylindrical and hollow with mounting triangle at base and extension at end. Motor shaft is cylindrical in different dimensions at different points. They are both symmetrical along its axis.

2. Dimensions & Size- Casing LengthXDiameter-8X6 cm, Shaft Length-12 cm, Shaft Diameters at L=0,2,7,9,10 cm-1,3.5,2.5,1.3,1 cm, Casing Weight-10-12 g, Shaft Weight-10-12 g, 3D

3. How shape affects and contributes to function- Extension keeps shaft in place. The cylindrical shape makes it easy for the shaft to rotate within the casing. The triangle mounting at the base obviously

II. Material – (Stainless Steel)

1. Why it is made from (Stainless Steel, Filling Material, Iron, Copper, and Ferrite magnet) –The shell is made of stainless steel to provide a strong casing and has ferrite magnets within to provide a magnetic field for the rotation of the shaft. The shaft is made of stainless steel, iron, copper, and a filling material. The stainless steel provides a strong core for the shaft in order to rotate the ES-GH gears. The other materials all deal with having good conductivity and magnetic properties to rotate when an electric field is present.

2. Alternative usable Material –Many of the metals used could have been interchanged as alternatives.

3. Outstanding Factors influencing the choice of material-High conductivity, Magnetic, Strength

A. Global

B. Societal

C. Environmental

D. Economic-Most of the material costs are low. Copper has a relatively high cost.

III. Aesthetics

1. Reason for Color – All materials are natural color except for filler. Steel and iron are gray. Copper is reddish orange. Filler is colored yellow to show where the iron plates are located within shaft.

2. Purpose for look –Functional purposes for look. The internal shaft is not meant to be seen and is covered by casing which is just functional in use as well.

3. Surface Finish –No surface finish

MANUFACTURING METHODS

I. Suspected Method – Turning

1. Evidence for Suspected Method-Rings along bases and sides of casing are visible.

II. Limits on Manufacturing-Must be round/axial

1. Limits from used Material- Filler applied after shape manufacturing.

2. Limits from shape and geometry- Axial shapes

III. Outstanding Factors for Manufacturing-

1. Global

2. Societal

3. Environmental

4. Economic-Cheap easy manufacturing

COMPLEXITY 1 – 10: 1= Simple 10 = Intricate

I. Scale Rating: 8

1. Criteria For Scale

A. Function-Just one function to rotate shaft by use of electric current.

B. Form-Many small pieces must be connected to accomplish shape. Magnets, iron plates, copper plates and wires must be attached by strong, durable adhesive.

C. Manufacturing-Turning is used for most of the manufacturing.

II. Complexity of component within the respective subsystem –

1. Main purpose of starter subsystem to give engine a jump start (fly wheel rotation)

2. Complexity Rating within its subsystem: 10

TH-A1 – Throttle Arm 1

FUNCTION

I. Performed function(s) -

1. Acts as an intermediate to control the engine idle speed by adjusting the throttle rod (TH-R).

2. Acts as a base to throttle spring 2 (TH-S2) which pulls throttle valve closed when throttle is not applied.

3. Acts as an intermediate to control throttle valve when starting engine by electric starter throttle control (ES-TC).

II. Flows

1. Kinetic Energy-Energy is transferred when the electric starter throttle control arm (ES-TCA) presses on the TH-A1 to open the throttle valve.

2. Internal Energy-Energy is transferred to the TH-S1 when spring is pulled on.

III. Environment

1. Temperature-Can range from the hottest and coldest weather conditions, plus extra heat provided by the engine.

2. Pressure-Atmospheric pressure

3. Chemicals-Atmospheric gases

FORM

I. Shape

1. Noticeable shape Properties- Flat bar with restraint on edge, symmetrical along axis, 2 holes along extension, pressed pin at base.

2. Dimensions & Size- Length-9.6 cm, Width at base-2 cm, Width at extension-1 cm, Thickness-0.2 cm, Height of restraint-1 cm, Weight-Approximately 2-3 g, Predominately 3D.

3. How shape affects and contributes to function- Wideness at base provides strong anchor, restraint provides a control on its range of motion, pressed pin allows for movement to control throttle rod (TH-R), 2 holes provide a mount for the TH-R and TH-S2.

II. Material – (Write what it is predominantly made of here)

1. Why it is made from (Stainless Steel) – Provides for a strong material with efficient load transfer and can withstand high and cold temperatures.

2. Alternative usable Material – Lead, aluminum, iron

3. Outstanding Factors influencing the choice of material- Strong, good temperature range, cost effective, easy to manufacture.

A. Economic-Cost effective, easy to replace.

III. Aesthetics

1. Reason for Color- Natural sheet metal grey

2. Purpose for look – Functionality-There is no need to paint or coat the TH-A1 and there is no purpose to aesthetically enhance it.

3. Surface Finish- No surface finish

MANUFACTURING METHODS

I. Suspected Method – Cast molding and metal working

1. Evidence for Suspected Method- Edging has streak lines and restraint is bent down from flat arm.

II. Limits on Manufacturing-

1. Limits from used Material- Not many limits. Stainless steel is versatile.

2. Limits from shape and geometry- Not capable of extrusion or pulling.

III. Outstanding Factors for Manufacturing-

1. Global

2. Societal

3. Environmental

4. Economic

COMPLEXITY 1 – 10: 1= Simple 10 = Intricate

I. Scale Rating: 2

1. Criteria For Scale

A. Function-A couple functions interact with the TH-A1

B. Form-Shape is specific to use

C. Manufacturing-easy to manufacture

II. Complexity of component within the respective subsystem –

1. The TH-A1 provides a central region to control the idle throttle and the starter throttle of the engine.

2. Complexity Rating within its subsystem: Subsystem has a low complexity, but the TH-A1 would rate a 6 within the subsystem.

PS-LC – Pull Start Locking Cylinder

FUNCTION

I. Performed function(s) -

1. The PS –LC is meant to lock the pull start subsystem to the engine flywheel (E-FW). Both the Engine Crank Shaft (E- CS) and the PC-LC are connected by 22 mm nut.

II. Flows

1. Rotational Motion- This component turns when the PS- RW is pulled to take the energy and transfer it to the flywheel.

III. Environment

1. Temperature- Normal and Standard Room Temperature.

2. Pressure-None

3. Chemicals-None

4. Majorly Open or Closed- Is a predominately open system component. It takes rotational mechanical energy and transfers it. Obviously some of the energy is lost due to the fact that no process can be completely ideal and reversible.

5. Noticeable Outstandings – This part is needed to start the engine.

FORM

I. Shape

1. Noticeable shape Properties-Hollow cylinder with a base containing 5 holes. Symmetrical along the base plane and height plane of the part. Has 5 rectangular slots near the top of the cylinder with an added grove on the rim.

2. Dimensions & Size- .0675m Height = .077m Weight = .14 kg Predominantly 3 dimensional.

3. How shape affects and contributes to function- The perfect cylindrical shape allows for rotational motion without losing too much of the rotational mechanical energy.

II. Material –Aluminum

1. Why it is made from Aluminum – Aluminum is a cheap and light material to manufacture parts from. Aluminum is most versatile metal that performs well under most conditions

2. Alternative usable Material – Any strong and heat resistant metal. Steel or iron.

3. Outstanding Factors influencing the choice of material-

A. Global – By using the common most metal on the earths crust it is readily available and used in most machines.

B. Societal- Aluminum is relatively safe because aluminum and aluminum alloys are strong.

C. Environmental- Bauxite is a plentiful substance on the earths crust which is used to make aluminum so there is small risk of depleting the world of the aluminum supply. Can be recycled and be reused.

D. Economic – Aluminum is a strong metal that gives the manufacture the best value for their dollar.

III. Aesthetics

1. Reason for Color – Natural color of material.

2. Purpose for look – Needs to be cylindrical to transfer rotational motion.

3. Surface Finish –The surface finish is relatively smooth but not to be aesthetically pleasing. Its looks are more dictated by its function. It smooth because it’s a rotating part, and it’s silver because the material is naturally silver after being put through the manufacturing process

MANUFACTURING METHODS

I. Suspected Method – Extrusion, Broached

1. Evidence for Suspected Method- The rectangular “punch outs” along the side of the cylinder means that they were probably broached. The cylinder as a whole was probably extruded from an ingot because of its shape.

II. Limits on Manufacturing-

1. Limits from used Material- This part was not able to be put in a grinder. Aluminum is unable to be ground because it can ruin the cutting edge on the grinder.

2. Limits from shape and geometry-It would be unwise to rapid prototype this part because of its simplistic geometry. This product was probably not sawn because it has to be precise to where it connects to the flywheel.

III. Outstanding Factors for Manufacturing-

1. Global - Skilled workers and sophisticated machines are required to make this part. So it would be rare to see it manufactured in a third world country.

2. Societal- The mass production of this part and most all of the components would create jobs.

3. Environmental - aluminum can be scraped and be reused.

4. Economic - The material and processes are all relatively quick and inexpensive.

COMPLEXITY 1 – 10: 1= Simple 10 = Intricate

I. Scale Rating: 5

1. Criteria For Scale

A. Function-The slots in it and the manner it connects the subsystems makes it fairly complex.

B. Form-Its simplistic geometry makes it fairly simple.

C. Manufacturing-it only has to undergo two manufacturing processes.

II. Complexity of component within the respective subsystem – Since the PS- LC helps transfer the rotational motion from the pull start system to the engine subsystem, it is an important component. Its function makes it an important component.

1. Complexity Rating within its subsystem: 6

OHV-EV – Overhead Valve Exhaust Valve

FUNCTION

I. Performed function(s) -

1. Opens and closes to allow exhaust gas from combustion chamber to exit to the muffler.

II. Flows

1. Heat in the form of hot exhaust gas passes through the OHV- EV.

III. Environment

1. Temperature- Hot Temperature. Has to withstand combustion.

2. Pressure-High pressure with the expansion of gas

3. Chemicals-Carbon Monoxide and other gases produced after combustion.

4. Majorly Open or Closed- Open because gaseous material flows through the valve

5. Noticeable Outstandings – Is composed of a valve with shaft attached. A spring and two caps are included in this component as well.

FORM

I. Shape

1. Noticeable shape Properties- Circular valve cap. Regular coil spring.

2. Dimensions & Size-Diameter= .03m, Height=.087m, Weight= .05kg, Predominantly 3 dimensional.

3. How shape affects and contributes to function-

II. Material – Aluminum

1. Why it is made from Aluminum – Aluminum is a cheap and light material to manufacture parts from. Aluminum is most versatile metal that performs well under most conditions

2. Alternative usable Material – Stainless Steel, Iron, or any metal the can withstand hot temperatures

3. Outstanding Factors influencing the choice of material

A. Global - By using the common most metal on the earths crust it is readily available and used in most machines.

B. Societal - Aluminum is relatively safe because aluminum and aluminum alloys are strong.

C. Environmental - Bauxite is a plentiful substance on the earths crust which is used to make aluminum so there is small risk of depleting the world of the aluminum supply. Can be recycled and be reused.

D. Economic - Aluminum is a strong metal that gives the manufacture the best value for their dollar.

III. Aesthetics

1. Reason for Color – Natural Color of Material with oil stains.

2. Purpose for look – No purpose

3. Surface Finish – The surface of the rod is polished and there are no sharp edges on the component. The component as a whole is oily. Oil is needed on this component because it is always moving up and down allowing for exhaust flow.

MANUFACTURING METHODS

I. Suspected Method – Drawn, rolled, turned, and forged

1. Evidence for Suspected Method- The rod and the spring were most likely drawn. If they were not they were rolled because of their round shape. The rod was probably turned as well in order to create the seams on it. The Caps and valve head were probably forged because of their overall flat circular shape. A Flash was probably left on the inside slot of one of the caps.

II. Limits on Manufacturing-

1. Limits from used Material- The aluminum material is very versatile but it cannot be used in a grinder. If used in a grinder, it would ruin the grind wheel.

2. Limits from shape and geometry- Nothing could be sawed. This component needed a high degree of precision to make. Since sawing is a relatively imprecise manufacturing process it probably wasn’t used.

III. Outstanding Factors for Manufacturing-

1. Global – Skilled workers and sophisticated machines are required to make this part. So it would be rare to see it manufactured in a third world country.

2. Societal – The mass production of this part and most all of the components would create jobs.

3. Environmental – aluminum can be scraped and be reused.

4. Economic – The material and processes are all relatively quick and inexpensive.

COMPLEXITY 1 – 10: 1= Simple 10 = Intricate

I. Scale Rating: 7

1. Criteria For Scale

A. Function – Because of the fact that this component is always moving and always transporting exhaust, its function is rated as very complex.

B. Form – Since this component is comprised of simple shapes its form is relatively not complex.

C. Manufacturing – since this component has to undergo multiple manufacturing processes, it is rather complex.

II. Complexity of component within the respective subsystem – This component helps the flow through the OHV subsystem. Without it, the exhaust gas would have no place to go, causing an overload of pressure inside of the combustion chamber.

1. Complexity Rating within its subsystem: 7

CA-FF – Carburetor- Fuel Float

FUNCTION

I. Performed function(s) -

1.Starts/stops fuel flow between fuel line (GT-FL) and mixing chamber of carburetor by inserting or removing a rubber-tipped plug into the fuel inlet.

2. Maintains ideal fuel level in CA-FR by tipping up or down based on fuel level, manipulating the fuel plug.

II. Flows -

1. Mass- Fuel flows over the stem of the fuel float, which closes and opens the fuel path thousands of times a minute.

2. Signal- It is the component of the carburetor that closes or opens fuel line.

III. Environment

1. Temperature- Low to Moderately high. Temperatures are higher than ambient temperature, but never are allowed to reach combustion temperature for gasoline.

2. Pressure- Relatively close to ambient pressure, with the minor added pressure of the head-pressure of the fuel line, which is almost cancelled out by the vacuum produced in the carburetor to draw in fuel.

3. Chemicals- Immersed in gasoline and air.

4. Majorly Open or Closed- The internal section of the hollow CA-FF is a closed system.

5. Noticeable Outstandings- None

FORM

I. Shape

1. Noticeable shape Properties- Semicircular, with cylindrical profile. A hollow plastic semicircular portion is joined together at its ends by a solid plastic mounting section equipped with a spring-mounted plug stem.

2. Dimensions & Size- Outside Diameter (OD)=4.5cm, Inside Diameter (ID)=2cm, H=2cm, Weight<10g.

3. How shape affects and contributes to function- The hollow characteristic of the component allows it to achieve its function of being a float-switch. The average density of the component is less than the density of gasoline. The Semicircular shape, which surrounds the fuel draw-line and traces the perimeter of the fuel reservoir allows the float to perform its function even if the fuel reservoir is not completely horizontal, or if the machine is not on a level surface.

II. Material – (Mostly plastic with a small steel spring and a rubber tip on the fuel plug-stem)

1. Why it is made from (Plastic) – Plastic is buoyant in gasoline when hollow, and will not deteriorate in gasoline.

2. Alternative usable Material – Rubber or other plastics. A less likely alternative, although possible, would be a very thin-walled hollow steel or aluminum float.

3. Outstanding Factors influencing the choice of material

A. Global- Plastic used is tolerant of all fuel grades available, including some with higher ethanol rating.

B. Societal- None

C. Environmental- Rubber tip on plug-stem allows for a tight seal, which prevents flooding or fuel loss.

D. Economic- Plastic is cheap and easy to manufacture in large quantities. Non-deteriorating materials will make replacement of altering very unlikely.

III. Aesthetics

1. Reason for Color – White is the natural color of this material.

2. Purpose for look – the form of this component directly follows its function with little or no consideration of aesthetics (Component not visible by consumer).

3. Surface Finish – The component is very smooth and non-porous. This reflects the need for the component to not absorb or retain any fuel, which would affect its density and decrease the functionality.

MANUFACTURING METHODS

I. Suspected Method – Injection Blow-Molded

1. Evidence for Suspected Method- Visible seam around the hollow portion. The solid parts were probably part of the perform, and the stainless steel spring was added after the injection blow molding.

II. Limits on Manufacturing-

1. Limits from used Material- Not tolerant of high temperatures. Hard to machine without distorting.

2. Limits from shape and geometry- Internal cavity can either be produced by joining two concave pieces or by blow-molding. The prior is more expensive and cumbersome than the latter.

III. Outstanding Factors for Manufacturing-

1. Global- None

2. Societal- Little need for manual labor, highly automated.

3. Environmental- Injection Blow-Molding wastes very little material and reduces required material to be involved in the component.

4. Economic- Blow Molding is cheap in high-quantities.

COMPLEXITY 1 – 10 1= Simple 10 = Intricate

I. Scale Rating: 7

1. Criteria For Scale

A. Function- This component has to float, has a spring-supported plug, and needs to function even if the fuel surface is not level.

B. Form- Mostly hollow with solid mounting section and fuel plug-stem.

C. Manufacturing- Manufacturing involves numerous processes if the joining of the multiple sections is considered.

II. Complexity of component within the respective subsystem –

1. This component is complex, and lies in a very intricate, complex subsystem (Carburetor). The Carburetor requires a very specific amount of fuel and air in order to supply the engine with a proper mixture. The Fuel Float allows for a constant, predictable source of fuel to be mixed with air.

2. Complexity Rating within its subsystem: 6

E-CS – Engine- Crank Shaft

FUNCTION

I. Performed function(s) -

1.Translates linear energy in the Piston to Rotational energy.

2. Controls timing of the OHV valves by turning the valve-actuating gear (E-VAG) .

3. Connects the fly wheel to the engine.

4. Passes energy from the engine into the shaft of the generator.

II. Flows -

1.Energy- Linear energy from the Piston is translated into rotational energy in the crank shaft, which is passed to the electric generator.

2. Signal- None

III. Environment

1. Temperature- High temperatures. Much of the heat from combustion is absorbed by this section of the engine. Temperature will never reach combustion temperature of oil, unless there is a critical failure.

2. Pressure- Relatively close to ambient pressure. The pressure will increase when the air in the engine cavity heats up.

3. Chemicals- Immersed in oil.

4. Majorly Open or Closed- This is a closed system, with the exception of heat flow.

5. Noticeable Outstandings- High stress is induced by the piston, thousands of times a minute.

FORM

I. Shape

1. Noticeable shape Properties- Solid steel. It is circularly symmetrical, with the exception of the off-centered section that is connected to the piston. This section is parallel to the rest of the component, but about 4cm displaced. There are two gears machined into the crank shaft. Overall the component is very substantial with large rotational inertia.

2. Dimensions & Size- Length=35cm, Diameter=4cm, H=10cm, Weight=5kg.

3. How shape affects and contributes to function- The off-centered portion of the crank shaft allows for the shaft to turn when linear force is applied to it. This allows it to accomplish its function of converting linear energy into rotational energy. The heavy, high inertia traits allow for momentum to build up, which reduces jarring changes in velocity.

II. Material – Steel

1. Why it is made from (Steel) – The steel used will tolerate the repeated stress induced to the component. Also, it has a relatively high density, which increases its inertia. This steel will also tolerate the chemical and thermal environment it is immersed in.

2. Alternative usable Material – Various types of steels, high carbon steels, or stainless steels. Other metals would work if they have high strength and won’t become brittle over time.

3. Outstanding Factors influencing the choice of material

A. Global- Readily available globally.

B. Societal- Material is tolerant of abuse, so it will not often require service or repair.

C. Environmental- Recyclable.

D. Economic- This is the cheapest material usable to attain required properties and life time.

III. Aesthetics

1. Reason for Color – Gray is natural color of the steel used.

2. Purpose for look – The form of this component directly follows its function with little or no consideration of aesthetics (Component not visible by consumer). The thick, heavy areas are designed either to strengthen the component or to increase inertia in certain areas.

3. Surface Finish – The component is very smooth wherever it slides in a bearing, and rough everywhere else. This shows that wherever a smooth, low-friction finish was needed, it was created. The rougher finish on the rest of the component allows oil, which helps cool and protect the component, to cling to the crank shaft.

MANUFACTURING METHODS

I. Suspected Method – Die casting with post-cast machining (surface finish), possible annealing and hardening. The gear teeth were probably finished after the part was cast.

1. Evidence for Suspected Method- Visible seam on the rougher surface. The smooth sections were probably turned onto the rougher part. The gear teeth most likely were hardened to bump up the strength and resistance to fatigue.

II. Limits on Manufacturing-

1. Limits from used Material- Material traits change during casting and machining, requiring annealing or hardening process stages to be added.

2. Limits from shape and geometry- The gears and off-centered section make it impossible to create on a lathe, and the complex shape and changing diameter make it impossible to extrude or to form. Machining the entire part would be very time consuming and expensive.

III. Outstanding Factors for Manufacturing-

1. Global- Method of manufacturing provides a sturdy, durable part. This reduces the need of maintenance in areas of the world that might not have access to proper equipment of facilities.

2. Societal- Little need for manual labor, highly automated.

3. Environmental- Die-casting leads to little wasted material. The machining is only used when it is required, and more efficient and less wasteful methods are used whenever possible.

4. Economic- Die-casting is cost-effective if quantities are large. The smooth finish added to only some parts saves money on unnecessary machining of the other sections.

COMPLEXITY 1 – 10 1= Simple 10 = Intricate

I. Scale Rating: 7

1. Criteria For Scale

A. Function- Component has to be able to turn on its axis without shaking the machine and also has to turn when linear force is applied to it.

B. Form- The high-mass sections allows for a balance of rotational inertia, even though it is not symmetrical. This reduces vibration.

C. Manufacturing- Manufacturing involves numerous processes even after the casting takes place. These processes include polishing and machining a smooth surface of some sections, cutting gears into casting, and hardening.

II. Complexity of component within the respective subsystem –

1. This component is complex, and lies in a very intricate, complex subsystem (Engine). The Crank shaft is the key to the energy transformation in the engine. The linear energy in the piston shaft pushes on the off-centered section of the crank shaft, which causes the crank shaft to rotate.

2. Complexity Rating within its subsystem: 5

F-DE – Frame-Engine Damper

FUNCTION

I. Performed function(s) -

1.This component is the mounting point that connects the engine to the frame.

2. Reduces vibration in the machine, which reduces stress on vital components and wandering.

3. Cuts down noise due to vibration of machine.

II. Flows -

1. Energy- Absorbs energy in the form of vibration that is created in the engine.

III. Environment

1. Temperature- Close to ambient, sometimes warmer due to waste heat and heat generated due to friction in damper. Always <50 degrees C.

2. Pressure- Ambient pressure.

3. Chemicals- Exposed only to air, sometimes exposed to spilled fuel due to its location under fuel tank.

4. Majorly Open or Closed- Closed

5. Noticeable Outstandings- None

FORM

I. Shape

1. Noticeable shape Properties- Engine damper consists of two plates with threaded rods protruding from them, the plates bent in various areas, that sandwich a square rubber piece between them.

2. Dimensions & Size- L=7cm, W=5.5cm. H=8cm.

3. How shape affects and contributes to function- Metal plates act as a mounting surface for the square rubber damper. Attached threaded rods allow the damper to be mounted between the frame and the engine.

II. Material – (Painted steel and Black Rubber)

1. Why it is made from (steel and rubber) – The steel provides a solid, durable, permanent mounting structure for the damper. The rubber, which is mounted between the two steel plates, absorbs the energy given to it from the engine, and passes very little through to the frame. Rubber allows the damper to perform its job of absorbing energy.

2. Alternative usable Material – Other forms of rubber would be acceptable. Another alternative would be a system of spring or air shocks. These two alternatives would increase cost.

3. Outstanding Factors influencing the choice of material

A. Global-The rubber and steel used are common materials used throughout the world.

B. Societal- The rubber damper will have a long life, but if it does deteriorate, it is easy and cheap to replace. The rubber also absorbs energy making the machine quieter and more tolerable in highly populated areas.

C. Environmental- The steel used is recyclable. By using rubber in this part of the machine, it decreases wear on many other components, cutting down on the need for replacement parts and materials.

D. Economic- This steel and rubber are cheap and easy to manufacture, maintain, and replace.

III. Aesthetics

1. Reason for Color – Black is a readily available color of the rubber, and the steel is painted black to allow for a uniform color. If the rubber were painted, the paint would flake off as the damper flexed and vibrated.

2. Purpose for look – The form of this component direrctly follows the function. The only consideration taken for aesthetics was the choice of color to paint the steel.

3. Surface Finish – The rubber is smooth, which makes it harder for a crack to start. The steel has been painted black with a protective paint to avoid any rusting or chemical decay. The steel is smooth to avoid any unwanted materials to bond to it.

MANUFACTURING METHODS

I. Suspected Method – The steel plates were most likely sheared or laser cut, and then formed on a break. The threaded rods were then inserted through holes in the plates and then welded. The rubber was probably the last to go on. It was molded around mounting stems that were welded to the steel plates.

1. Evidence for Suspected Method- The Steel plates are of uniform thickness, which suggest they came from a sheet, and were cut or stamped out. There is a visible weld around the threaded rods, which prove they have been welded on. The rubber has a visible seem that shows they were molded.

II. Limits on Manufacturing-

1. Limits from used Material- Rubber is heat sensitive, which means it had to go on after the other pieces were welded on. The use of more than one material demands multiple steps in forming the part. The

2. Limits from shape and geometry- There is no uniform dimension or useful symmetry, so the parts could not be extruded. Also, there are overhanging sections that would make it near impossible to die-cast.

III. Outstanding Factors for Manufacturing-

1. Global- None

2. Societal- Little need for manual labor, highly automated.

3. Environmental- All materials have been reduced, cutting down waste. The rubber used is very tolerant of abuse, cutting down damage to other components, reducing need for shipping replacement parts and wasting materials.

4. Economic- Stamping and forming sheet metal is simple. The molded section is a very simple shape, reducing cost on complex dies.

COMPLEXITY 1 – 10 1= Simple 10 = Intricate

I. Scale Rating: 4

1. Criteria For Scale

A. Function- This component needs to mount permanently, support a heavy engine, and also be flexible.

B. Form- A Complex shape consisting of multiple materials.

C. Manufacturing- Manufacturing involves numerous processes applied to different materials, including welding, forming, and casting.

II. Complexity of component within the respective subsystem –

1. This component is about average in complexity relative to the Frame subsystem. It performs a complex function of reducing vibration, but is a somewhat simple solution to the task.

Solid Modeled Assembly

Explanation of CAD Package and Components

The choice of Computer Aided Drafting (CAD) package was Autodesk Inventor 2011. This package was chosen because it can provide the necessary functions to create the solid model assembly that we saw fit to detail our product. The package was also free for students to download from the Autodesk website. Only one of the members has a background in a 3-D modeling program, Solidworks, but the program was not readily available or free to download. So by default, Autodesk Inventor was the choice of CAD package.

The group believed that the most beneficial system to model would be the piston cylinder. It is integral to the function of the generator and can provide important representations of the function of the piston. During disassembly the group took great interest in the piston components. Every gas engine contains a piston device of some sort and the group believes it is a system that should be looked into further. With a solid model to simplify and represent how it functions, we can better understand the processes that occur within a 4-stroke engine. We can also use this model as a reference for our engineering analysis. Thus out of pure interest and importance of the piston cylinder device, we decided to solid model the piston, piston arm, intake valve, and exhaust valve.

Assembly

Figure 14: Piston and Combustion Chamber

Figure15: Piston Arm with Piston Assembly

Figure 16: Overhead Exhaust Valve and Piston Assembly

Figure 17: Final Piston Assembly

Engineering Analysis

Introduction

Below are three Analysis problems that all relate to the four stroke combustion function of the generator. If needed refer to the solid modeling section above for a better understanding of the piston cylinder arrangement. Also, we have assembled four photos that help aid in the understanding of the four stroke combustion function that we are referring to in the Engineering Analysis.

The three problems focus on the Detailed design, Testing and Validation, and Concept development stages of the Design process. For the sake of clarity, the Analysis process for each section has been limited to the first four steps. After the first four steps for each analysis, a brief paragraph has been provided which explains how the respective problem statement relates to its respective design stage.

Four Stroke Cycle Photos

Figure 18: Phase 1

Figure 19: Phase 2

Figure 20: Phase 3

Figure 21: Phase 4

Friction and Manufacturing - Concept Development

Problem Statement

In the combustion chamber it is ideal to have the smoothest surface possible between the cylinder wall and piston. We want to know the best manufacturing method to make the piston cylinder arrangement that can be used in the combustion function. What we need to find is the manufacturing method that gives the best surface finish. We will consider Broaching, Drilling, Grinding, and Extruding, Casting.

Diagram

Figure 22: Friction Diagram

Assumptions

1. The piston cylinder arrangement can be any basic geometric shape (ie. circular, rectangular, etc.)

2. The overhead valve can fit onto the piston cylinder arrangement.

3. The Piston cylinder is to be made out of steel.

4. Neglect cost of manufacturing for the sake of answering the problem statement.

5. These manufacturing processes are available.

6. Material is available.

Governing Equations

1. Friction = µ N

2. Steel to Steel - µs = .7 µk = .6

This problem Statement would fall under the concept design stage in the design process. The nature of this problem allows for a lot of creativity and generalization. For example there are not too many equations or assumptions needed because this problem falls into an early stage of the design process. From this problem, we generate 5 concepts we can work with: Broaching, Drilling, Grinding, Extruding, and Casting. From there we can study the pros and cons of each method and choose a method that would yield the best surface finish. When exploring these 5 concepts, we can further discuss detailed and embodiment designs for each. Then we will be able to choose the best manufacturing method.

Power and Efficiency - Testing and Validation

Problem Statement

Given length of open space in combustion chamber, open and closed, the diameter, and the mass of the piston head, determine the power of the piston in the combustion chamber and determine the efficiency of the power input compared to the final generator output as stated in the specification sheet.

Diagram

Figure 23: Dimensions 1

Figure 24: Dimensions 2

Assumptions

1. Neglect friction on the piston from the combustion chamber

2. Assume pressure on piston is uniform

3. Assume generator power output is constant

4. Assume in testing, temperature(input/output) and time can be measured

Governing Equations

In the Testing and Validation step of the design process, an experiment would be performed to determine a few key factors in the analysis process. This would include several runs determining temperatures and the time taken for the piston to move from the initial to the final stage. These factors would then be used in the analysis process to find power input and ultimately efficiency. This is done specifically to test performance in the Testing and Validation step.

Volume of Combustion Chamber - Detailed Design

Problem Statement

Find smallest dimensions of the combustion chamber using the volume of air and fuel needed per stroke. These dimensions can then be used during the manufacturing process. Determine the volume of the mixture of air and fuel needed per stroke using the desired energy per stroke. The volume of air found would contain the minimum amount of oxygen necessary for combustion. The ideal gas constant R is 8.314 kJ/kmol*K. The MW of C8H18 is 114.23 g/mol. The density of liquid C8H18 is .703 g/mL.

Diagram

Figure 25: Combustion Chamber Volume

Assumptions

1. Diatomic oxygen constitutes for 20.8% of the total air.

2. Air is an ideal gas.

3. The air entering chamber is at standard temperature and pressure.

4. A value for the desired energy per stroke.

5. The only substances entering chamber are the calculated volume of air and fuel.

6. The fuel is fully combusted, outputting its full energy potential as indicated in the chemical equation.

Governing Equations

where r = radius of piston head and h = length of combustion chamber.

This analysis can be used as an aid in the 5th step of the design process, detailed design. The dimensions of the needed combustion chamber can be found by finding the volume of air and fuel per stroke. By using the energy per stroke value, as specified by the company, we can manipulate the chemical equation to find exact amount of fuel and air needed in molar quantities. From moles of air, volume can be found using the ideal gas equation, and from moles of C8H18, using the molecular weight of C8H18, mass can be found. Then from mass, volume can be found by the density of C8H18. The volume of fuel/air mixture is now available so the radius and length of the piston cylinder chamber can be determined.

Design Revisions

When choosing our design revisions, we addressed all four factors of design: Global, Societal, Economic, and Environmental. However some of the design revisions focus more on one or two design factors than the others. The frame upgrade addresses societal and economic, The Gas Tank revision focuses on economic and environmental, and the Fan cover focuses on global and societal.

Gas Tank Upgrades

The below design revision is an option available to the consumer. This revision would be in both the honeywell's and the consumer's best interest as viewed from an economic standpoint. However this revision would be harmful from an environmental standpoint. Details on the revision are below.

I. Included Components -

1. GT (Gas Tank)

II. Alterations -

1. Combinations of Components- GT combined with GT-TE to increase the size of the gas tank.

2. Removals- N/A

3. Additions- GT-TE (Gas Tank-Tank Expander) to be used as an optional expansion to the standard gas tank.

4. Other Modifications- N/A

III. Factors of Alterations -

1. Global- N/A

2. Societal- N/A

3. Economic- Honeywell can manufacture this product and make more of a profit by selling this as a separate component for purchase for customers who wish to have the generator last through the night on one tank of gas. This also saves the consumer money by reducing their amount of trips to the gas station.

4. Environmental- This addition would be worse for the environment. Consumers would run their generator longer thus producing more harmful carbon emissions.

IV. Improvements -

1. GT-TE will be designed to be attached to the gas tank so that the generator can run through the night with out the gas tank having to be filled

Figure 26: Simple Small Gas Tank Addition

Frame Upgrades

This design revision is meant to improve the ergonomics of the Generator. By adding a shopping cart style wheel, the product would be more appealing to a wider marketing audience. Below are the details to the Frame revision.

I. Included Components -

1. F-A (Frame Axel)

2. F-ABR (Frame Axel Bracket)

3. F-SL (Frame Stand Leg)

4. F-W (Frame Wheel)

II. Alterations -

1. Combinations of Components-F-A combined with F-W to make self mounted wheels.

2. Removals-F-A and F-ABR removed.

3. Additions-F-WB (Frame Wheel Bracket) to mount wheels in place

4. Other Modifications-More rugged F-W’s that rotate for better maneuverability. Thicker, stronger F-SL for sturdier performance.

III. Factors of Alterations -

1. Global- N/A

2. Societal-Product mobility to the user is enhanced. Turns are easier to make with rotational wheels.This improvement would improve the ergonomics of the generator making it more appealing to the consumer.

3. Economic-Supports a better value to the user. This could be used as a marketing strategy. Minimal cost to achieve these goals. Two parts are removed and replaced with one, which evens out cost. The thicker steel F-SL may have extra cost, but minimal. Such cost would encompass small components, connections, and extra material.

4. Environmental- N/A

IV. Improvements -

1. F-SW is designed with thicker steel so that it is sturdier than before.

Figure 27: Wheel Revision

Removable Electric Generator Fan Cover

This design revision was made to directly affect the accessibility of the engine. By adding this revision, Honeywell and Honda could advertise the generator as an easily accessible product that the average "Joe" could preform maintenance on. This Design revision is outlined below.

I. Included Components -

1. Electric Generator- Fan Cover (EG-FC)

II. Alterations -

1. Combinations of Components- NA

2. Removals- NA

3. Additions- Possible louvered cover to be attached to a frame

4. Other Modifications- The Fan cover, in its current design, is not removable. The bolts holding it on are inaccessible. To improve upon this design, we suggest making the bolts connecting this component accessible from the outside of the machine. This might require larger openings in the fan cover itself, or a modified design of this component. The fan cover could be an open frame, with a mountable screen, instead of one component with a permanent screen.

III. Factors of Alterations -

1. Global- NA

2. Societal- The current design makes service impossible without damage to product.

3. Economic- Making an easily removable fan cover would add a slight cost to manufacturing, but would decrease in cost of service and support.

4. Environmental- By modifying the fan cover fixtures we do little to affect the environment. The fan size itself would not change, thus creating no impact.

IV. Improvements -

1. Engine block would be open-able

2. Electric generator would be serviceable

3. Consumer would be more satisfied with product