Group 1 Honda Generator-Component Summary

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Complexity Scale
1 Low Complexity - The part is made up of less than 6 individual pieces AND The function of the part is easily understood and requires no research or testing/observation. For example an aperture nut is only one part and just by looking at it you can easily understand that it is used to hold the crankshaft to the flywheel.
2 Medium Complexity - The part is made up between 6 - 15 individual pieces OR The function of the part is understood only after some research/observation. For example the Choke linkage has more than 6 parts and unless one knows the makeup of the carburetor its function would be extremely hard to understand.
3 High Complexity - The part is made up of 16 or more individual pieces OR The function of the part is not easily understood (or understood at all) and requires extensive research/ observation. For example the generator has well over 16 parts and without understanding hoe electricity and magnetism interact one would have no chance of understanding the inner working of the generator.

Contents

Gas Tank

The Gas Tank

Function

The gas tank has two main functions. The first major function of the gas tank is to contain, preserve and protect the gasoline. The second major function of the gas tank is to act as a roof for the engine and generator components by preventing liquids and debris from interfering with the components of the generator. The gas tank is associated with the flow of gasoline (chemical energy) to the engine. The gas tank performs in the multiple environments depending on the weather, it can function is almost any environment except extreme heat and temperatures below the freezing point of gasoline.

Aesthetics

The component is large and red (the universal color to indicate gasoline containers), made of stainless steel, it is a large hollow rectangular shape with rounded edges and a seam around the outside where it was spot welded together. This component is 3-dimensional. The color is its only aesthetic property. The component is 2' 1.5" x 1' 5.5" x 5". (LxWxH) the size of the gas tank allows the tank to cover the engine and generator , also the hollow shape is necessary to contain the gasoline and prevents spills, leaks and evaporation. The gas tank weighs about 5 lbs. The tank was made of stainless steel because it doesn’t rust and will be unaffected by the constant contact of the gasoline, it can also stand bombardment by most types of weather.

Manufacturing

The gas take was manufactured using the metal forming, likely stamping or drawing. The lack of tabs rule out casting, and rapid prototyping would be much too expensive for mass production. Then machining was used to cut out the holes for the cap and indicator. Finally spot welding is used to join the 2 halves together. This can be seen in the small circular depressions around the seam. These manufacturing methods were chosen because they are the cheapest for the part’s shape and material type. Because stainless steel is a metal and therefore welding and extrusion work best.

Complexity

The gas tank can be rated Low on the predefined complexity scale. The above categories only support this because of the lack of steps in the manufacturing, as well as the lack of functions and interaction within the component.

Frame

The Frame

Function

The Frame surrounds and protects the generator from outside forces mainly at the more fragile corners, it also provides handhold for moving the generator. also on some select models it acts as a mooring for wheels and handles. There are no flows associated with the frame, but the rubber dampening pads between the frame and inner components help to dispel vibrations. The frame performs in the multiple environments depending on the weather, it can function is almost any environment except extreme heat.

Aesthetics

The frame is 3 dimensional measuring 2' 3.5" x 1' 9.5" x 1' 9.5". The frame comprised 2 round tubes bent in 4 places to create a rounded corner rectangle with a 4 crossbars joining the tubes, 3 of the crossbars are soldered on, and one is held on by bolts for easy removal and replacement of the inner components. The shape of the frame allows it to protect the generator without restricting access to the generators inner components and controls. The frame weights roughly five pounds and is made likely from iron, dues to the black paint finish it is impossible to tell without removal of the finish. Iron is a reasonable assumption though because the frame has to be strong and rigid, and iron is the cheapest materials that will accomplish this job. also the paint finish may be necessary to protect iron from rust, whereas this would be unnecessary with stainless steel. The frame has a dull black paint finish likely to reduce glare and help the generator to stand out against most backgrounds. It also protects the frame from rusting my both sealing the pores of the metal and preventing it from coming in direct contact with water. Therefore the finish is both aesthetic and functional.

Manufacturing

In order to make the frame 5 manufacturing methods are needed, extrusion is first used to create the hollow tubing, then bending in order to crate the curved corners, then machining to add the necessary holes for nuts bolts and other attachments, then welding in order to attach cross bars and attach the 2 sides of the frame, and finally an unknown combination of finishing operations ending in either spray painting or electromagnetic coating for the black finish. though no evidence suggests the extrusion or the machining we believe that this was used because they are cheap and widely available methods used in the creation of this kind of part. Evidence supporting out guess of bending can be seen in the wrinkles on the inside of the corners of the frame.

Complexity

This component would be rated Low on the above defined complexity scale. the previous categories support this because of the frame's lack of moving parts and contribution to the main function of the generator.

Control Panel

The Control Panel

Function

the control panel receives and transfers user input signal to the generator, it also outputs the electrical energy generated by the generator. it is associated with the signals and electrical energy flows within the generator. The gas tank performs in the multiple environments depending on the weather, it can function is almost any environment except extreme heat and environments that would cause water to degrade the contacts for signal communication.

Aesthetics

The control panel is primarily 2 dimensional and a rectangular shape the edges jut out about half an inch beyond the panel to create a contact area and protect the more fragile switches and outlets to a certain extent. The panel measures 10.5" x 8.5". the shape allows the switches and to be displayed in the open for easy access by the user while also protecting them from unnecessary wear and tear. it also spaces the outlets far enough away from each other to allow larger plugs access to the electrical energy.

Manufacturing

The control panel was likely created from only injection molding because it was plastic and the injection tabs are clearly visible on the back. injection molding was chosen because it was cheap , and widely available due to its common usage, also because plastic is most easily formed with injection molding.

Complexity

The control panel would be rated Low on the above defined complexity scale due to its number of parts.

Battery

The Battery

Function

The battery is used to store and regulate the current of the electricity coming from the generator, it also stores power so that the push button starter can start the engine without any energy input. The battery is associated with the flow of electrical energy withing the generator. The battery can function in any environment so long as nothing can short circuit the contacts, and the temperature of the battery is kept between −20°C and 45°C.

Aesthetics

The battery is a medium, sized 3 dimensional rectangle measuring 6" x 3.5" x 4.5" and weighs roughly 3 pounds. the shape of the component does not affect its functions so much as it makes it easy to carry as well as keeping it stable. its outside is made of plastic and insides are unknown. an educated guess leads us to believe that it contains metals (because battery acid is corrosive) as well as Nickel Cadmium battery acid. The properties of the Nickel Cadmium battery acid allow the battery to hold and regulate the current. the plastic is black in order to keep the battery a neutral color, whereas the contact coverings are black and red to indicate negative and positive respectively. this is both functional and aesthetic.

Manufacturing

The battery was likely created from only injection molding because it was plastic and the __ are clearly visible on the back. injection molding was chosen because it was cheap , and widely available due to its common usage, also because plastic is most easily formed with injection molding.

Complexity

The battery would be rated Low on the above defined complexity scale due to its small number of parts.

Generator Core

File:Generator core.jpg
The Generator Core

Function

The generator core is designed to transform rotational mechanical energy into electrical energy through the rotation of permanent and electromagnets withing and around a copper coil. this component is associated with the flows of rotational energy inputted from the engine and electrical energy outputted to the control panel. the generator can operate in most environments where small particle or liquids cannot penetrate the cover and cause friction or short circuits within the generator.

Aesthetics

the generator core is a 3 dimensional cylinder measuring 11" in length with a diameter of 8". Like all cylinders it is symmetrical around its center axis. weighing roughly 60 pounds it is made of aluminum, iron, copper, plastic and other unidentifiable materials. all of these materials were chosen for their beneficial properties. Aluminum because it is light, strong and not magnetic, iron because it is magnetic and can be used to create an effective electromagnet, copper because it has a very low resistance at normal temperatures, and plastic because of its extremely high resistance. the other materials are assumed to have similar properties necessary for the function of the generator. because the generator core is hidden both under the fuel tank and covered by a protective plastic sheet it was not given any kind of aesthetic finish.

Manufacturing

The generator core was manufactured in many steps, the iron parts were likely machined from slugs created by an extruder, the aluminum was likely die-cast to create the base, the copper wiring was extruded and the plastics were injection molded, there connections needed to be made most of the materials had to be machined and then soldered or welded together. then a robot was was likely used to precisely assemble the parts. each method was chosen based on the material and the cost effectiveness of that method.

Complexity

The battery would be rated High on the above defined complexity scale due to the large number of moving parts as well as the total number of parts. it is also has many different interaction both between itself and other components as well as withing the core. the importance of the generators functions as well as the precisions of the assembly and the number of steps in manufacturing the generator core support this complexity rating.

Pull Starter

The Pull Starter

Function

The pull starter is designed to transform the rotational mechanical energy supplied by the operator to initiate engine rotation to start the engine. The pull starter has numerous flows associated with it. Human signal as well as human energy is inputted into it, which are then transformed into mechanical energy, which is utilized by the engine. The pull starter is comprised of primarily plastic, which allows it to function in virtually any environment except for high temperature extremes, as that would melt the plastic, and prevent the component from rotating.

Aesthetics

The pull starter can be simplified geometrically to a circle. Since the pull starter is circular it has rotational symmetry about its center point. The pull starter is primarily two-dimensional; it has very little depth to it. The pull starter has a 8.5 inch diameter on the bottom, a 6.75 inch diameter on the top, and a 2 inch depth to it. The pull starter’s geometric shape was selected based on its function, the pull start initiates the rotational energy of the engine, which is why it is circular so when the operator pulls on the string which is wrapped around it, the pull starter will spin and provide rotational energy to the engine. The component roughly weights 5 ounces. The pull starter is manufactured almost entirely of plastic, which was selected as a material due to its low cost, and insulating properties. Aesthetics due play a role in this component; it was painted red to make it more visually appealing, and make it easier to notice to prevent individuals from accidentally colliding with the generator, which would be catastrophic.

Manufacturing

The pull start was most likely manufacturing utilizing injection molding. Injection molding was likely used due to the fact the component is primarily plastic, which injection molding is primarily used for. Furthermore, there are visible parting lines on the component, which is an indicator of injection molding. Economic factors were considered in this decision because injection molding is among the cheaper manufacturing process, and plastic is an inexpensive material.

Complexity

The pull starter can be rated Low on the predefined complexity scale. The pull starter has a low complexity because it is a fairly simple component; it is a plastic circle, which provides rotational energy to the engine. It is manufactured using simple materials, and a simply process.

Muffler

Function

The muffler is a component, which is used within the generator to reduce the level of noise emitted by the exhaust system. The muffler is associated with the flow of chemical energy in the form of, Carbon Monoxide, Nitrogen dioxide, Sulphur dioxide, which are byproducts of combusting gasoline. The muffler is comprised of primarily steel, which allows it to function in virtually any environment except for high temperature extremes, as that would melt the steel.

Aesthetics

The general shape of the muffler is a rectangle. The muffler is a three dimensional component, with dimensions 9.5 inches in length, 4.25 inches in width, and 5 inches in depth. The mufflers rectangular shape is related to the component it performs because it reduces the sound by creating destructive interference, where opposite sound waves collide with each other as a result of a series of tubes. The rectangular shape is utilized to allow for a large interior volume for the tubes. The muffler weighs roughly 10 ounces. The muffler is comprised primarily of steel, which was selected due to the fact that steel has a high melting point, which is necessary to withstand the high temperature of the gasoline exhaustion. The muffler has a dark paint finish to protect it from being exposed to liquids and rusting.

Manufacturing

The muffler was manufactured using a variety of manufacturing method. The muffler was manufacturing using stamping due to the fact that the muffler appears to be one major piece, except for the narrow rod, which is the exit. The narrow rod is wielder onto the muffler, and appears to be manufactured by drawing it. I suspect that it was drawn due to the fact that it has the same cross-sectional area and has visible lines along its side. These manufacturing methods were selected because they are relatively inexpensive.

Complexity

The muffler would receive a rating of Medium on the above complexity scale due to the number of parts and number of interactions within.

Kill Switch

The Kill Switch

Function

The kill switch is a way to shut off the generator in an emergency situation in which it cannot be shut down properly. Unlike the normal shut down, which shuts down all systems down correctly and without damaging them, the kill switch is designed to immediately stop the system at all costs, which includes damaging the system. The flow associated with the kill switch is the human signal input to terminate the generator operation. The kill switch can perform in virtually any environment except extreme heat as that would melt the plastic which compromises it.

Aesthetics

The general shape of the Kill Switch is a rectangle. It is primarily two-dimensional. The dimensions of the kill switch are 4 inches in height, 2.5 inches in width, and 1 inch in depth. The kill switch is a rectangle because a rectangle is an easy button to push, if the kill switch were a different shape such as a triangle or circle it would be harder to push. The component weighs roughly 3 ounces. The kill switch is made of plastic due to its ability to act as an insulator, and low cost. The switch has a slightly rough finish to make it easier for the operator to press, if the switch did not have a rough finish on it then when the operator went to press the kill switch he would have a harder time doing so due to a lower friction. The rough finish allows the operator to have an easier time pressing the kill switch.

Manufacturing

The kill switch was most likely manufactured utilizing injection molding. Injection molding was likely used due to the fact the component is primarily plastic, which injection molding is primarily used for. Furthermore, there are visible parting lines on the component, which is an indicator of injection molding. Economic factors were considered in this decision because injection molding is among the cheaper manufacturing process, and plastic is an inexpensive material.

Complexity

The kill switch can be rated Low on the predefined complexity scale. The kill switch receives a Low because it is a fairly simple component; it is a plastic rectangle, which provides terminates the operation of the generator. It is manufactured using simple plastic materials, and a simply process of injection molding.

Cooling Fan

Function

The sole function of this component is to create an air flow across the engine to cool it down. This component does so by rotating in sync with the flywheel and the effect of the fins pushing through the air rapidly creates turbulence in the air resulting in an air flow across the engine. Flows associated with this component are limited to the flow of air resultant from the rotation of this fan. This component functions in whatever environment is present during operation. This includes atmospheric pressure, ambient temperature and relative humidity.

Aesthetics

This component is cylindrical in its overall geometry. Notable properties include the obvious symmetry associated with a cylinder and the pattern of the fins symmetrically placed along the circular base on the fan. This component is three dimensional in its geometry yet two dimensional in its rotation about its central axis. This component is approximately 23 centimeters in diameter by approximately 10 centimeters high and approximately one kilogram in weight. The form of this component is integral in its function. The cylindrical orientation of the fins allows for maximal surface area along which the stagnant air can be agitated. This component is made entirely from plastic. The plastic must be stiff enough to resist the force of the air pushing against the fins during rotation. Global factors influencing this decision include the availability of the raw materials necessary to manufacture this component. Societal factors include the safety of this component and the chance of injury to the user during operation. Economic factors include the material cost and the cost of the manufacturing process used to form the plastic. This component was not designed with aesthetics in mind. This component is the natural white color of the plastic used to create it. The surface finish is smooth with the exception of seams left from the molding process that formed this component. This is neither for functional nor aesthetic purposes; however the smooth finish lends itself to a safe smooth surface for the user to contact if necessary.

Manufacturing Methods

Injection molding was used to form this component as evidenced by the smooth surface finish and noticeable seams along the vertical axis. Material choice impacted this decision in that plastic is easily formed this way as well as the fact the plastic cannot be machined, or pressed due to the complex geometry of the fins and the uneconomical nature of rapid prototyping. Global factors affecting this decision include the availability of the raw materials necessary to manufacture this component. Societal factors include the overall safety of this part while in operation as well as while stationary. Economic factors include the cost of the material used and the cost of the process by which the component is manufactured. Environmental factors include the recyclability of this component and the material it is made of.

Complexity

The Cooling Fan would receive a rating of Low on the predefined complexity scale due to its simplicity.

Fan Shroud

The Fan Shroud

Function

This component covers the plastic cooling fan and the flywheel. It also lends itself as the attachment point for the recoil starter. The perforations in the cover also allow for the surrounding air to be pushed by the air flow resulting from the rotation of the fan within the shroud. This resultant airflow helps cool the engine. Flows associated with this part are limited to the flowing air resulting from the rotation of the fan. This part operates in an open air environment subject to the ambient temperature, atmospheric pressure and relative humidity.

Aesthetics

This component has a general concavity from the reverse side. Its outside edge conforms closest with the geometry of a circle for the most part, with a trapezoidal protrusion outward from one side. It has no outwardly notable properties and is primarily a three dimensional part. The part is approximately 35 centimeters long, 10 centimeters wide and 24 centimeters high. The components shape is coupled to the task it performs by its geometry; it is a cover and therefore is convexly formed in order to provide space for the part to be covered. This part weighs approximately 2.5 kilograms and is made from a low strength steel due to the fact that it is mainly for aesthetic and safety conveniences and it can be formed to its final shape relatively easily. No specific material properties are needed for this part to function. Global factors influenced the material choice because it is available worldwide. Societal factors include the overall safety of the part. Environmental factors include its ability to be recycled and used again and economic influences include the low cost and high availability of low strength steel. This component is painted red with a smooth surface finish and an elegant sloping appearance in order to be aesthetically pleasing. It is painted red to conform to the overall color scheme of the product. The smooth surface finish not only makes this part more aesthetically pleasing, but also limits burrs and edges on which the user can be injured.

Manufacturing

The fan shroud was most likely pressed from a flat sheet of steel using mechanical force. This is evidenced by the component’s simple geometry as well as the lack of any seams and a smooth surface finish with no noticeable machining marks. Both the material and the shape of the part impact the method by which it is manufactured. The material impacts the decision because low strength steel is relatively easily pressed into a final shape. The final shape impacts this decision because the simple geometry is easily produced from a press and does not require a more intricate process to be formed. Global factors influencing this decision include the availability of the raw materials necessary to form this component. Societal factors include the overall safety of this component. Environmental factors include the recyclability of the material used to make this component. Economic factors include the cost of the material and the cost of the manufacturing process.

Complexity

The Fan Shroud would receive a rating of Low on the predefined complexity scale due to its simplicity.

Air Filter

The Air Filter

Function

The sole function of this component is to draw air in from the environment and force it through an oil impregnated sponge that filters out dust and dirt particles from the air, before the air enters the carburetor. Flows associated with this component are limited to the flow of air through the filter housing, through the filter itself and finally into the carburetor. This component functions in the natural environment present at the time of operation. This includes the atmospheric pressure, ambient temperature and relative humidity.

Aesthetics

The general shape of this product is that of a rectangular box. There are no outwardly notable properties attributed to this primarily three dimensional part. The outer casing is approximately 16 centimeters long by 10 centimeters wide by 27 centimeters high and weighs approximately 2.5 kilograms. The shape of this component’s interior is integral to performing its function efficiently. Air enters the outer casing through a small cut out rectangle, approximately 2.5 centimeters wide by 8 centimeters high, and travels along a channel to the oil impregnated sponge. If not for the guidance of the airflow channel this product would not work nearly as efficiently due to the chaos of normal air flowing around the entire cavity and not necessarily being driven directly through the filter and into the carburetor. The exterior of the air filter is formed from steel, while the inner air channel and filter housing are made of plastic. Manufacturing decisions impacted this mainly as a result of the complex geometry of the inner air channel and the plastic filter housing. The permeability of the filter sponge is integral to the function of this component. Global factors include availability of the materials to be used. Economic concerns include the cost of the raw materials and the cost of the manufacturing process to create the finished product. Environmental concerns include the recyclability of the materials used. Societal concerns include the safety of this component, whether or not there is a distinct possibility of injury because of the components surface finish, or general geometry, neither or which are grave concerns for this part. This component is aesthetically appealing due to its smooth surface finish. The black paint job also adds an aspect of a sleek look to it. The component is painted black to correspond with the overall color scheme of the generator. The smooth surface finish is mainly for aesthetic purposes, but also lends itself to a safer part overall due to the lack of burrs or scratches that could potentially injure the user.

Manufacturing

The outer shell of the air filter was pressed into its final shape using mechanical force. The inner plastic pieces were formed by injection molding. Evidence supporting this is the lack of machining marks on the metal components as well as their relatively simple geometry, as well as bits of flash remaining and noticeable seams from the molding process of the plastic and the plastic’s inability to be machined due to its softness. Material choice had a distinct impact on how the plastic was formed. Plastics are relatively soft materials and therefore are not applicable to machining processes and the complex geometry limits the ability of the plastic to be formed by pressing, and rapid prototyping is not a worthwhile choice economically. Global concerns include the availability of the materials necessary. Economic concerns include the material cost and the cost of the process by which the part is manufactured. Environmental concerns include the recyclability of the materials used.

Complexity

The Air filter would receive a rating of Low on the predefined complexity scale due to its simplicity.

Choke Linkage

The Choke Linkage

Function

The function of the choke linkage is to control the choke valve within the carburetor. This component also helps govern air flow under various throttle conditions. When the choke lever is pulled to the “choke” position (out toward the user), the choke valve closes to restrict airflow to the carburetor and when the choke lever is pushed back into the “open choke” position the choke valve opens to allow more air to flow to the carburetor. The choke linkage also helps to govern air flow by way of a lever arm, held in place by a spring that controls a pushrod that pushes or pulls on a horizontal bellows, approximately the size of a quarter in diameter, to inflate or deflate the bellows. On the other side of the bellows is a rubber tube approximately 10 centimeters long, with a unidirectional flow valve at the end. This valve is the connected to the carburetor engine interface via another rubber tube. The tube is clamped to a spigot on the carburetor engine interface’s exterior. A smaller hole is contained within the spigot and extends through to the inner diameter of the carburetor engine interface. This entire secondary assembly can be considered a pressure sensor. This pressure sensor helps control air flow through the carburetor into the engine under various throttle positions. The hole within the carburetor engine interface has air flowing past it at a certain pressure, into the engine. When the choke lever is placed in the “open choke” position, the choke linkage only turns the choke valve to approximately a one quarter open position. Depending on the pressure of the air flowing past the hole within the carburetor engine interface, the high pressure air within the bellows will be pulled down through the rubber tube, through the unidirectional valve, through the other connecting rubber tube and into the lower pressure airflow going into the engine. When this happens the bellows collapse and the push rod is pulled in with the bellows. This inward motion pulls the choke linkage further back than the “open choke” position can move it, thus opening the choke valve more, allowing more airflow through the carburetor and into the engine. Depending on the throttle position the air pressure flowing through the carburetor will be larger or smaller and the bellows will react appropriately to the given pressure which will cause the choke valve to open or close accordingly. The only flow associated with this component is the flow of air through the choke valve and the flow of air through the rubber tubes. This component operates in the atmospheric conditions present during the time of usage, which includes the atmospheric pressure, the ambient temperature and the relative humidity.

Aesthetics

The general shape of this component is a trapezoidal figure with a circular bellows and cylindrical rubber tube attached. The component does not have any axial symmetry or other notable physical properties and is primarily three dimensional. The component is approximately 10.5 centimeters long (not including the rubber tube which adds an extra 20 centimeters), by 5 centimeters wide, by 10 centimeters high. The shape dictates the function of the subcomponents within the linkage assembly, the outer plates onto which all subcomponents are attached, are primarily flat with openings cut for the linkage to move in its appropriate direction. The choke lever’s shape restricts its movements to a horizontal, linear displacement, the lever arm attached to this moves horizontally in an arc to push or pull the push rod of the bellows. The entire assembly weighs approximately 140 grams, the weight of an average cell phone. The majority of the subcomponents are made of steel, with the exception of the rubber tubes and the plastic unidirectional valve. Manufacturing decisions impacting this component include the necessity of a light to medium strength material that can be easily bent and formed into a final shape and retain that shape, while still being cost effective. Global factors affect the material decision due to availability of the materials necessary. Environmental factors include the recyclability of the materials used. There is no social impact from these material choices. Economic factors include material availability and cost of attaining and forming the materials. This component is bland and uninteresting aesthetically. The aesthetic purpose of this component extends only to the outer plates which hide the intricate linkage behind them. The component is the natural base silver metallic color of the steel used, with the exception of the black rubber tubing. The surface finish is smooth due to the natural surface finish of sheet steel, before manufacturing, this is mainly to limit possible injury to the user because of burrs or scratches in the metal.

Manufacturing

The outer plates and lever arm are pressed into their final shape using mechanical force, the outer plates are the welded together to form a box-like structure, and the remaining linkage components were formed by bending a steel wire to the desired shape. Evidence supporting this includes the lack of marks in the surface finish that would be left by a machining process, the lack of seams that would be left by a casting process and the detrimental cost of rapid prototyping these components. Material had little impact on this decision, however the geometry of the subcomponents supports the decision to press the flat parts using mechanical force and bend a steel wire into its final shape again employing the use of mechanical force. Global factors that influenced this decision include the relative availability of the materials used. Environmental factors influencing this decision include the recyclability of the materials. Economic factors include the material cost and availability. There are no societal impacts on this decision.

Complexity

The Choke Linkage would receive a rating of Medium on the predefined complexity scale due to its number of parts.

Governor Linkage

Function

The function of this component is to link the electronic servo governor to the throttle valve and control how open or closed the throttle is depending on the signals received by the governor. If the throttle valve is to be opened to increase engine speed, or closed to decrease engine speed, the governor will pull on a lever arm or push on the same lever arm, respectively. That lever arm is connected to the governor spring, which is linked to the governor arm. The governor spring receives a signal from the governor to open or close the throttle; this signal is then translated into a linear motion of the governor arm. The motion of the governor arm then pulls or pushes on a connecting rod, which connect the governor arm to the throttle valve, and this pulling or pushing will open or close the throttle valve, respectively. Another function of this component is the prevention of engine surges by the use of an anti-surge spring that runs parallel to the connecting rod and limits the ability of the governor to pull open the throttle thus resisting engine surges due to insignificant voltage changes within the governor.

Aesthetics

This part is mostly linear in its geometry with the exception of the coils of the springs. This component is primarily two dimensional due to its linear motion and relatively flat construction. This component is comprised of two springs, a larger one called the governor spring and a smaller one called the governor anti-surge spring, a connecting rod and two pressed pieces of steel linked at one end by way of a journal bearing with two synthetic washers riveted loosely into the journal bearing. One of which is located between the two pieces of metal and the other between the rivet cap and the top piece of metal in order to reduce friction upon rotation of the two steel plates. This component is approximately 32 centimeters long by 10 centimeters wide (measured from governor spring on the left to the connecting rod on the right). The component is made primarily of steel, with the exception of the synthetic cloth washers which are nylon. Manufacturing decisions did not play a major role in the choice of materials for this part. The elasticity of the coiled steel spring is necessary for this component to operate properly. Global concerns of this material choice include the availability of the necessary materials. Economic concerns include the cost of the materials and the cost of the specific manufacturing process used. Environmental factors include the recyclability of the materials used. Societal concerns include the overall safety of this part. This component was not created with aesthetics in mind. The component is the base sliver metallic color of the raw materials, with the exception of the governor spring which is painted black to distinguish it from the governor anti-surge spring. This distinguishment is likely made to clearly depict which spring the user is not to touch in this system. The anti-surge spring may need adjusting, but the governor spring is not meant to be altered. The surface finish is smooth to reduce friction between the governor arm plates so they will be able to rotate easily.

Manufacturing

The steel plates were pressed from flat pieces of steel to their final shape using mechanical force and the springs were coiled from drawn steel wire. Evidence supporting this includes the smooth surface finish of the steel coupled with the lack of any machining markings as well as the fact that the formation of a tension spring involves bending a metal wire to coil the spring. Material choice is not dire to this component yet the robust nature of the steel allows for this part to move constantly for long periods of time with minimal wear. The shape of this part influenced the manufacturing process selected due to the simple geometry of the pressed plates and the coiled nature of a tension spring. Global factors include the availability of the raw materials necessary. Societal factors include the safety of the part once it has been manufactured, the smooth finish limit possible injury to the user. Economic factors include the cost of the materials and the cost of the manufacturing process used. Environmental factors include the recyclability of the materials used.

Complexity

The Governor linkage would receive a rating of medium on the predefined complexity scale due to its number of parts.

Carburetor

The Carburetor

Function

The carburetor has 3 functions. First, the carburetor must import gasoline from the tank and air from the atmosphere, to the combustion chamber. Second, it must regulate the air-fuel mixture to provide maximum power to the engine. This mixture is not constant and depends on the speed at which the engine is running. Finally, the carburetor must provide a mechanism to restrict flow to the engine and thus kill the engine. This carburetor - which will now be referred to as simply the "carb" - operates in an environment of air mixed with gasoline. It is also subjected to high air velocities and low pressures, as well as high moderately high temperature due to its proximity to the heat generating engine..

Aesthetics

This shape of this component is critical. It is fully 3 dimensional. It can best be described as cylindrical, with additional pieces added and removed. It is approximately 12 cm x 6cm in diameter. It weighs about 1-2 kg. There is a large hole running parallel to the diameter of the cylinder. The bottom section is hollow. There are many small holes/ports drilled in various locations. The shape is coupled to the function in various ways. The bottom section (float chamber) is hollow to store a small amount of fuel, as governed by a plastic floater and rubber stopper on a hinge. The hole through the body narrows slightly in the middle. This narrowing is called a venturi. When the engine intakes air, the narrowing of the venturi causes the air to gain velocity and lose pressure (venturi effect). This reduction below atmospheric pressure allows the fuel in the float chamber to be pushed by atmospheric pressure up through a small hole between the float chamber and the venturi. This is what mixes the air and fuel. Also inside this venturi are 2 butterfly valves, called the throttle valve and the choke valve. The throttle valve, located at the engine side of the fuel jet, closes completely to block airflow entirely. The choke valve, located before the fuel jet, has a small hole it to allow air to flow in even when it is completely closed. Both valves are linked to plastic control surfaces at the top of the carb. There are several holes in the carb, for fluids, mounting, and control pieces. There are also 3 very small ports located under the throttle valve, and a brass needle valve to adjust these ports. The purpose of these holes is to compensate for the lack of fuel delivery from the main jet, when it is operating at low speed and the vacuum from the venturi is inadequate to supply enough fuel. The carb is made primarily from aluminum, but also has a few small pieces of plastic, a rubber hose and gasket, a brass needle valve, and some steel hardware. Manufacturing was probably not the reason for choosing these materials. There are other materials that would be more easily machined, like plastic. The reason for choosing aluminum is because it is cheap, strong, and can with stand the forces and elements it is subjected to. The floater is made of hollow plastic to ensure that it is light enough to actually float on the fuel. Rubber hosing was chosen because it is inert enough for fuel, flexible enough to bend around components, and can withstand the heat of the engine. The gasket is also rubber for its flexible nature and its ability to create a hermetic seal. Economic factors were the key factors in choosing these materials. a number of other metals have the required properties for this component, however, aluminum provides the required properties cost effectively. The carb was not designed with aesthetics in mind. It is barely visible and the consumer has no direct interaction with it at all. The surfaces are unfinished and the aluminum still rough from the mold it was cast in.

Manufacturing

To make this part, several manufacturing methods were used. The main aluminum body was cast as evident by the rough finish and seam lines. Half of the venturi has a rough casting finish, and the other half has a smooth finish with very small helical grooves. This is evidence that it was bored. There a many small holes drilled in the body also, some of which have been plugged with a lump of yellowish metal, probably brass. This was likely done to drill some holes which could not be reached directly. The 2 flat faces each side of the venturi, which connect flush with the air filter and the carb-engine interface, were cut with a circular saw. This is clear from the circular grooves on the faces. As a economic concern, casting was chosen over machining, because it wastes significantly less material, and takes less time to produce the complex geometry. This means the manufacturer can spend less on materials and get the product to market faster.

Complexity

The Carburetor would receive a rating of high on the predefined complexity scale due to its number of parts and difficulty to understand

Spark Cap

The Spark Cap

Function

This component has 2 functions. The first function of this component is to generate a high voltage pulse - on the order of 10 kV - such that a spark can be generated in the spark plug in order to combust the air/fuel mixture in the cylinder. The second function is to be precisely timed. The high voltage pulse be perfectly in sync with the beginning of the power stroke phase, in order to most effectively generate high pressures needed to drive the piston. This Component receives both a signal and a magnetic flux from a permanent magnet affixed to the flywheel. As this magnet passes by the magneto, the laminated steel core channels most of the changing magnetic flux through a series of copper windings around the steel core. This rapidly changing magnetic flux induces a high voltage difference in the spark cap relative to the grounded engine body. This potential difference cause the electrical arcing in the spark plug necessary to ignite the fuel mixture. By playing the permanent magnet at a very precise location on the flywheel, the precision synchronization between the spark and piston location can be achieved. This component is required to operate in high temperatures as it is direct contact with a combustion engine. It is not subjected to and liquids.

Aesthetics

This component is primarily 3 dimensional. The general shape of this component is approximately 20 thin sheets of steel (most likely silicon steel, for reduced electrical reisitivity and therefore reduced eddy currents), approximately 8cm x 3 cm x 0.5 mm. Around this core there is a plastic and resin shell than encases the copper windings. Coming out of this shell are the spark cable and ground cable, which are approximately 30cm and 45cm, respectively. At the end of the spark cable is a cylindrical plastic spark cap, approximately 8 cm long. The shape of the steel layers is coupled to the function. The side closest to the spinning magnet on the flywheel is machined so that it has a radius of curvature that matches the flywheel. This is to most effectively transmit the magnetic flux to the steel layers. Laminated layers - as opposed to a solid block of steel - is used in order to reduce resistive loses, due to eddy current being generated in the steel. The shape of the spark cap is such that it can be easily removed, for spark plug maintenance. this component weighs roughly 0.5 - 1 kg. This component is made from steel, copper, plastic, rubber, brass, and some form of insulating resin. The primary reason for choosing these material was not manufacturing, but function. The steel is chosen to guide the magnetic flux because it has a high magnetic permeability. The copper was chosen because it has a low resistivity. Rubber was chosen as a flexible insulator. Plastic was chosen as a rigid insulator. The main concern for this component was economic concern. Copper is not the best conductor, however, it provides adequate electrical performance at the lowest price. Plastics is also very inexpensive to make and to manufacture. Also, there is a societal concern regarding the potentially hazardous high voltuage produced. the conductor in the spark cap is deeply recessed within the plastic housing, possibly to prevent injury to the consumer. Aesthetics were not really a factor for this component, as it is completely hidden inside the engine(with the exception of the spark cap/cable). The color of this component is simply the color of the raw materials it is made up of. There is no additional finish on this component.

Manufacturing

This component utilizes multiple manufacturing methods. The steel core was formed by die cutting the shape out of a sheet of steel, then stacking the layers together and crimping them together. The crimped holes are clearly visible. The plastic and rubber parts were formed by injection molding, as evident by the seam that runs along each part.

Complexity

The Spark Cap would receive a rating of Medium on the predefined complexity scale due to its difficulty to understand.

Fly Wheel

Function

The flywheel only has a single function. The weight of it creates a large amount of inertia, therefore giving it great momentum so that the engine can continue its cycle despite pressure in the opposite direction. This also has the added benefit of reducing vibrations. The flywheel is associated with the flow of mechanical rotational energy from the engine to the generator. The flywheel can function in any environment because its function (momentum) does not depend on its surroundings.

Aesthetics

The flywheel is a large circle. It has a 10 inch diameter with a 2 inch lip around the outside, it is radially symmetrical in quarters and is primarily 2 dimensional. For a body to have momentum it must be moving, so in order for the Flywheel to have momentum but not move it must be circular, thus the designers chose a gear shape for it, its weight of about 25lbs, helps this function. The designers chose to use steel in the creation of the flywheel due to its durability and extremely high melting point. Though steel is not the only material that would allow the flywheels to function it is the most efficient. Because the flywheel is hidden withing the engine block is has no aesthetic properties. Its only finish is the the teeth around the edges are sanded down for a more precision.

Manufacturing

The flywheel was most likely created using the method of sand casting. This can be seen in the un-finished areas of the flywheel, the rough surfaces has the texture of sand. Because this is a cheap and cost effective way to create steel parts it can be said that the material choice did affect the manufacturing methods. The shape also had an effect, because of the holes and ridges, as well as some the teeth of the flywheel sand casting was necessary as conventional molds would not be effective.

Complexity

The flywheel would be rated Low on the above defined complexity scale due its single part and its easy to understand function.

Crank Shaft

The Crank Shaft

Function

The crankshaft has one main function and that is to transform reciprocating linear piston motion into rotation. there is a single crankshaft used in the generator. the flow of mechanical energy from the gas engine to the generator is associated with this component. It functions in any environment as long as it is not hot enough to melt the metal.

Aesthetics

The crankshaft is a long 3 dimensional shaft of 14 inches with varying diameters, the widest being4 inches. the shape of the crankshaft is optimized for the highest TDC and lowest BDC of the piston. It weighs roughly 5 lbs. It is made of steel because of the inconsistency of forces being applied to it, therefore the durability of steel is necessary. The crankshaft has a smooth finish with gray color which is that of the steel. The smooth finish of the crankshaft limits the amount of drag so it can function optimally.

Manufacturing

In order to make the crankshaft it is forged through the process of roll forging and is hardened through induction hardening because it makes the crankshaft lightweight and it is cheap also. It also allows for very precise dimensions along the crankshaft. It then polished to reduce the drag at the bearings.

Complexity

The crankshaft would be rated as Medium Complexity on the above defined complexity scale due to its importance and the precision necessary for it to function within the engine. The crankshaft interacts rather simply with the surrounding parts with simple connections to the flywheel and the piston.

Engine Oil Sensor

File:Engine Oil Sensor.jpg
The Engine Oil Sensor

Function

The engine oil sensor tracks the amount of oil inside the engine. There is only one. It consists of sensors at the bottom of the oil filter that track the oil content. It functions as a safety measure so that the generator is not used at any point without oil.

Aesthetics

It is a small black plastic sensor. It is small and weighs little so that it does not affect any other functions. It is made of plastic because it is not a main component of the generator so it can be made cheaply.

Manufacturing

The engine oil sensor was likely created from injection molding because it is plastic. Injection molding was chosen because it was cheap , and widely available due to its common usage, also because plastic is most easily formed with injection molding.

Complexity

The engine oil sensor would be rated a Low on the above defined complexity scale due to the fact it is not necessary and can be cheaply made in mass production.

Pushrods and Tappets

The Riders

Function

The function of this component is to open and close intake andexhaust valves. It does so through the use of two cams located on the camshaft, which rotates in synch with the main crankshaft via a gear. The rotation of the camshaft dictates the movement of the pushrods. As the crankshaft rotates the shape of the cam forces one of the tappets upwards, this upward motion pushes on the pushrods which rest in the tappets. The upward motion of the pushrods press one end of a lever called a rocker arm which opens the valve in question to allow either the inflow of combustion gasses or the outflow of exhaust gasses. Two cams,180 degrees out of phase, rotate and operate the valves. When the intake vale opens the exhaust vale is closed and vice versa. The only function of this component is operating the intake and exhaust valves. Flows associated with this component include the inflow and outflow of combustion gasses and exhaust gasses respectively. This component operates in the interior engine environment. This includes the viscous oil lubricating the system and the high temperature regime within the engine block.

Aesthetics

The pushrods are simply linear, cylindrical rods with rounded ends. The tappets consist or a circular base with a vertical cylindrical extension that is cupped to cradle the lower end of the pushrod. Notable properties include a vertical axial symmetry of both parts and horizontal axial symmetry of the pushrods. The pushrods are primarily one dimensional, whereas the tappets are primarily three dimensional. The pushrods are approximately 16 centimeters long and 3 millimeters in diameter, the base of the tappets are 2.5 centimeters in diameter by 1 millimeter high and the cylindrical protrusion is 7 millimeters in diameter by 4.5 centimeters high. The pushrods weigh apporoximately 25 grams each and the tappets weigh approximately 50 grams each. The shape of this component is the governing factor in its success. The shape of this component is integrally connected to its function in that the linear vertical design allows the force of the cams’ rotation beneath the tappet to be transferred along the pushrod to the rocker arm to operate the valves. This component is made from steel, manufacturing decisions influenced this due to the fact that the material chosen must be applicable to a turning process to achieve the desired form. Resistance to heat and toughness are necessary for this component to operate being that it is in a high temperature regime during operation and takes repeated striking force from the cam during every engine cycle. Global factors influencing this include the availability of the raw materials necessary for manufacturing. Environmental concerns include the recyclability of the material used and economic factors include the cost of the material coupled with the cost of manufacturing the final product. Aesthetics were not considered when designing this part as it is an interior part and would not be accessed by the user unless they were servicing their unit. The component is the silver metallic color of steel due to the fact that it has no surface coating. The surface finish of this component is very smooth for precise operation within the engine.

Manufacturing

These parts were most likely turned using a machining process to remove excess material from the component until it reached its final shape. Evidence supporting this includes the cylindrical nature of the component and the tell-tale rotational surface markings present on the component. The components shape impacted the method chosen as a result of the specific geometry of the part and necessary precision. Global concerns include the availability of the raw materials used. Societal concers include the overall safety of the part, it is smooth and safe to handle. Economic concerns include the cost of the material and the cost of the machining process used. Environmental factors include the recyclability of this component.

Complexity

This component receives a rating of 2 because of the simplicity of it function.

Piston

The Piston

Function

The Piston/Connecting rod serve 2 functions. Firstly, the piston must bear the pressure of the combusted gasses in the cylinder, and convert the boundary work done by the gasses on the piston into a rotational kinetic energy in the crankshaft. Also, it must lubricate the moving parts by splashing oil from the oil pan up onto them. The piston receives energy from the high pressure gasses and exports that energy as mechanical energy. The component functions in a high  temperature environment.

Aesthetics

This component weighs approximately 2 kg. The piston head is 8.5 cm in diameter x 6.6 cm at its widest point. It is a round in one plane. The connecting rod is 16 cm long, 2.5 cm x 2.5 cm at the thinnest section, and 6 cm x 2.5 cm at the end that attaches to the crank shaft. It is primarily 3 dimensional. The circular shape is critical to the function. Any deviation from a perfect circle will result in a leaky seal between the piston and the cylinder. This could result in reduced chamber pressure, and ultimately a decreased overall efficiency. Also, for all the circular surfaces on this component including the piston, and 2 journal bearings, and imperfections in the shape would cause vibrations, stress concentrations, increased wear, and reduced longevity. This bulk of this component is made from aluminum, with some steel hardware. The steel pieces include 2 bolts that attach one end of the connecting rod to a cap, which come together around the crankshaft, forming a secure bearing. manufacturing processes were not the main concern for the material choice. Aluminum was chosen because it is lightweight and cheap. Since the connecting rod moves back and forth hundreds if not thousands of times per minute, and the accelerations are governed by the RPMs, having a large mass would increase the forces required to operate at that speed. This is directly from Newton's 2nd law of motion. The bolts are steel because the concentration of stress is beyond the capacity of aluminum. Economic concerns were to use as little material as possible and thus save money. Global, societal and environmental concerns were not factors in this components design. ​This component was not designed with aesthetics in mind and it is and internal component, and  entirely occluded from view. The component is gray and this is just because the color of the structural material is gray. Some parts are polished smooth, but this is purely for performance.

Manufacturing

This component was made from cast aluminum as evident by the rough texture and longitudinal seams. Material choice did not impact this as casting is the generally most efficient way to make a component. This part as also machined on a lathe and band saw as evident by circular grooves on the outside wall of the piston and the contact surfaces of the bearings, and the parallel lines on the connecting rod and cap. The shape impacted the method because lathing creates the high precision required for optimum performance. The primary concern for the manufacturing of this component was economic. The methods employed are the most cost effective methods to produce this part. This component receives a 2 on our complexity scale. The component interactions are not very complex.

Complexity

This component receives a 2 on our complexity scale. The component interactions are not very complex.