Product Manufacturing Analysis g152011

Manufacturing Methods

Part: Large Housing Gasket

• Manufacturing Methods: Die cut
• Evidence: Visible signs of a blade cutting the edges to make the shape from a press with the sides of the gasket being compressed.
• Did Material Choice Impact Manufacturing: Yes, the material (rubber) was needed to make a seal in the motor to create sufficient compression and to prevent leaking of air and fluids.
• Did Shape Impact Manufacturing: Yes, because it is two dimensional; die cutting is easy to produce large quantities of a simple 2 dimensional component.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Easily mass produced and cost efficient

Part: Small Housing Gasket

• Manufacturing Methods: Die cut
• Evidence: Visible signs of a blade cutting the edges to make the shape from a press with the sides of the gasket being compressed.
• Did Material Choice Impact Manufacturing: Yes, the material (rubber) was needed to make a seal in the motor to create sufficient compression and to prevent leaking of air and fluids.
• Did Shape Impact Manufacturing: Yes, because it is two dimensional; using die cutting it is easy to produce large quantities of a simple 2 dimensional component.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Easily mass produced and cost efficient.

Part: Carburetor Gasket

• Manufacturing Methods: Die cut
• Evidence: Visible signs of a blade cutting the edges to make the shape from a press with the sides of the gasket being compressed.
• Did Material Choice Impact Manufacturing: Yes, the material used (rubber) was needed to make a seal in the motor to create sufficient compression and to prevent leaking of air and fluids.
• Did Shape Impact Manufacturing: Yes, because it is two dimensional; die cutting is easy to produce large quantities of a simple 2 dimensional component.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Easily mass produced and cost efficient
  • Social- Reduces vibrations that cause noise

Part: Crankshaft Housing

• Manufacturing Methods: Die casting
• Evidence: The housing is made from a die cast with visible flash marks as seen on the bottom of the housing.
• Did Material Choice Impact Manufacturing: Aluminum can be easily heated and formed to a shape using a cast.
• Did Shape Impact Manufacturing: The design does not warrant the time or effort to be milled or machined.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Money and time were saved using die casting rather than milling.

Part: Cylinder block

• Manufacturing Methods: Die casting and then milled
• Evidence: The cylinder block is first cast this is evident because of the visible flash marks as seen on the bottom of the housing and the cylinder hole is milled so it can attain the necessary precision.
• Did Material Choice Impact Manufacturing: Aluminum can be easily heated and formed to a shape using a cast and then milled.
• Did Shape Impact Manufacturing: This piece needed to have a high precision so it was necessary for it to be milled after it was cast
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Money and time were saved using die casting and then milling instead of milling the entire thing.

Part: Piston

• Manufacturing Methods: Die casted and milled
• Evidence: The piston was made from a die cast as can be seen on the inside of the piston and the outside is milled to a specific diameter which is evident through smooth lines on the outside of the piston.
• Did Material Choice Impact Manufacturing: Steel can be easily heated and formed to shape and then altered after by milling to achieve specific dimensions within tolerances.
• Did Shape Impact Manufacturing:
  • The inside of the piston is too hard to be milled or machined and is easier to be casted, especially since it has no vital operation.
  • The outside needed to be very accurate so milling was the obvious choice.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- Die-casting is cheap.
  • Environmental- Not a lot of waste compared to milling the entire piece.

Part: Flywheel

• Manufacturing Methods: Die casted
• Evidence: Visible signs of flash marks on the underside of the flywheel. A part with so many features would be too costly and time consuming to be milled.
• Did Material Choice Impact Manufacturing: Steel can be easily heated and melted to form desired shape.
• Did Shape Impact Manufacturing: Yes, you need something that could produce good dimensional accuracy, and make a well balanced part. Otherwise, the part could do damage to the rest of the machine.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- Die-casting is cheaper than milling would have been.
  • Environmental- Not as much waste as milling or investment casting would have created.

Part: Magneto and magneto wire

• Manufacturing Methods:
  • Copper wires were drawn
  • Main housing was forged
• Evidence: A piece of iron was forged to give it a general shape. This evident by the flash on the outside edges of the component. The inner wires were drawn and then pressed together and placed inside the casing.
• Did Material Choice Impact Manufacturing: Yes, metal was needed and the easiest way to get metal to the desired shape is through a combination of manufacturing processes. Copper was chosen for the wires because it can be easily drawn and is highly conductive.
• Did Shape Impact Manufacturing: Yes, the shape of the casing was easily made with casting and the wires on the inside were easily drawn.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic: Casting is relatively a cheap way to make this part on a large scale.

Part: Carburetor

• Manufacturing Methods:
  • Cast and die cut parts
  • Milled hole
• Evidence: The body of the carburetor is casted from steel and can be seen by flash marks. The hole inside the steel is machined out to a specific diameter, and is evident through very smooth walls and circular lines on the inside. The brass plates are forges out of a large piece of metal and are evident through the rounded edges to where the force was applied on the outside of the plates.
• Did Material Choice Impact Manufacturing: Steel can be formed to shape in a cast when heated and then then milled to specifications, and strength was needed in all of these pieces.
• Did Shape Impact Manufacturing: The body of carburetor has many intricate designs which would be too costly and time consuming to mill, and the hole milled inside could not be casted to dimensions within tolerances any other way.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Environmental- These parts that would not deteriorate or rust and last for extended periods of time.
  • Economic- These parts will likely never need to be replaced.

Part: Crankshaft

• Manufacturing Methods:
  • Cold rolled then milled shaft
  • Forge counterweights
• Evidence: The shaft starts as a solid piece of cold rolled steel and is milled down to specific dimensions which can be seen by the smooth lines on the outside of the shaft. The threads at the end are also milled after the width is determined to be true. The counterweights at the end of the crankshaft are forged out of a piece of steel which is evident through the rounded edges and the straight lines present on the side of the weights from the force of the die on the metal.
• Did Material Choice Impact Manufacturing: Yes, steel is a strong material but can be shaped to specifications, and strength and geometric detail were needed for these pieces.
• Did Shape Impact Manufacturing: Yes, cylindrical shape can be easily milled in a lathe and counterweights shape can be easily forged.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Strong long lasting piece of metal was turned into the pieces we need for this component in an economically sound way.

Part: Bearing

• Manufacturing Methods:
  • Casted and polish balls
  • Cut and extruded pipe casing
  • Injection molding rubber spacer
• Evidence:
  • The bearings are casted pieces of steel to create near perfect spheres and are then polished to create a smooth surface and less friction.
  • The housing of the bearings appeared to be cut from a steel pipe to size and then polished to reduce friction.
  • The plastic/rubber spacer was made by injection molding which is evident through parting lines.
• Did Material Choice Impact Manufacturing: Yes, the steel balls needed to be strong and durable. The casing needed to be strong to protect bearings, and the rubber created an effective spacer.
• Did Shape Impact Manufacturing: Yes, it would have been hard to mill a sphere (and there would have been a lot of waste in that process) and tubing is easily cut while the rubber can be easily molded into any shape.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- Smooth working engine creates less problems for the consumer
  • Economic- Casting is cheaper than many other comparable methods.

Part: Clutch

• Manufacturing Methods:
  • The shoes were cast and then milled
  • Spring was drawn and tempered
• Evidence: To get the initial shape of the shoes it was most likely cast, and then to get it to its current shape it was probably milled. The body of the clutch is machined and milled to the required dimensions and is evident with no flash marks found and smooth lines appearing around the edges to which the shape is made. The spring is made by hot winding a heated wire around a mandrel and then it is removed immediately and cooled in oil. The spring must then be heat treated to make the spring strong and able to handle stress and return to its original shape.
• Did Material Choice Impact Manufacturing: Steel is rigid and can be milled at a rapid pace for production. Steel springs preserve shape and rigidity, and is the strongest, inexpensive material suitable for the functions the spring must be able to perform.
• Did Shape Impact Manufacturing: Yes the shape is relatively simple, but needs a lot of work to make it. To make this part quickly and efficiently it would need to be cast and then finished off by milling.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Casting is cheap (after the initial cost of the mold), and milling gets it to the specific dimensions needed.

Part: Pull Start Mechanism

• Manufacturing Methods:
  • Injection molded casing
  • Woven rope
• Evidence: The plastic casing was made using injection molding and can be seen by parting lines and tapered edges. The rope is made of woven nylon.
• Did Material Choice Impact Manufacturing: Yes, plastic was used because it needed to be lightweight and the extra strength and weight not be necessary.
• Did Shape Impact Manufacturing: No because the best way to manufacturing this piece was to investment mold it. CNC machining would be the best to make this piece, but the amount of money needed to do this would not be worth it.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal factor- needed to be smooth for the consumer to pull
  • Economic needed to be cheap enough material so it does not significantly raise the price.

Part: Clutch Shroud and Casing

• Manufacturing Methods:
  • Casing- Injection molding
  • Shroud- Forged
• Evidence: The plastic casing was manufactured using injection molding and can be seen by parting lines and tapered edges. The solid end piece is formed by a press to create the semicircular extruding steel inside the shroud.
• Did Material Choice Impact Manufacturing: Yes, investment molding was chosen because plastic was used; this because it needed to be lightweight and the extra strength and weight provided by metal was not needed. Forging was selected because it was the best way to shape the metal. This needed to be strong enough to withstand the force applied from the spinning clutch.
• Did Shape Impact Manufacturing: Yes, the easiest way to make the plastic into the shape it needed to be was through injection molding. The best way to give the metal its shape was through forging because it allowed the metal to keep its strength without adding too much cost to the process.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- Must have a nice appearance because it’s a visual to the consumer
  • Economical- Plastic was used for the casing because it’s cheap

Part: Washer

• Manufacturing Methods: Forged
• Evidence: Forging is evident flash left on the outer edges.
• Did Material Choice Impact Manufacturing: It is easiest to forge a shape like a washer.
• Did Shape Impact Manufacturing: It is a simple shape so forging would be sufficient in making the shape.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Forging is economical on a large scale
  • Environmental- There is very little waste from this process

Part: Head Spring

• Manufacturing Methods: Drawn and tempered
• Evidence: Springs are made by hot winding a heated wire around a mandrel, removing it immediately, and cooling it in oil. The spring must then be heat treated to make it strong and able to handle stress and return to original shape.
• Did Material Choice Impact Manufacturing: Yes, steel can be easily shaped when heated and strong enough to retain shape.
• Did Shape Impact Manufacturing: Yes, this is the only way to make a proper spring.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- This process is rather quick and inexpensive on a large scale

Part: Trigger Mechanism

• Manufacturing Methods:
  • Plastic was injection molded
  • Spring was drawn and tempered
• Evidence: The trigger and trigger casing are made by injection molding and can be seen through part lines and reset marks. The spring is made by hot winding a heated wire around a mandrel and then removed immediately and then cooled in oil. The spring must then be heat treated to make the spring strong and able to handle stress and return to original shape
• Did Material Choice Impact Manufacturing: Yes, the best way to get plastic into a form is to injection mold it; plastic was used because it needed to be lightweight and the extra strength and weight was not needed by a metal. Steel springs are only really made through the one process.
• Did Shape Impact Manufacturing: Shape is intricate and can be easily made from a molding. The spring can only be made the one way.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- create comfortable trigger for the consumer to use. Also since it’s made of plastic it does not add a lot of weight to the machine.

Part: Support Handle

• Manufacturing Methods: Injection molding
• Evidence: The handle is made by injection molding and can be seen through reset marks and tapered edges.
• Did Material Choice Impact Manufacturing: Yes, plastic is best formed through injection molding, and plastic was used because it needed to be lightweight and the extra strength and weight given by metal was not warranted.
• Did Shape Impact Manufacturing: Complex shape can be easily molded out of plastic.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- It makes the tool more comfortable for the consumer to use
  • Economic- Plastic is cheaper than metal

Part: Air Filter and Casing

• Manufacturing Methods:
  • Plastic was injection molded
  • Spring is drawn and tempered
  • The filter is made of foam
• Evidence: The plastic outer casing is made by injection molding and is evident through reset marks found. The spring is made by hot winding a heated wire around a mandrel and then removed immediately and then cooled in oil. The spring must then be heat treated to make the spring strong and able to handle stress and return to original shape.
• Did Material Choice Impact Manufacturing: Yes, plastic is most easily formed with injection molding. Plastic would be the desired material for this piece because it is lightweight. Steel springs are most easily made with the process discussed above.
• Did Shape Impact Manufacturing: Shape can be easily molded from plastic. Steel spring would be too costly and not as effective if made using any other method.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Plastic is less expensive than metal
  • Social- Being made out of plastic reduces the weight of the machine

Part: Throttle Cable

• Manufacturing Methods: Drawn and woven steel
• Evidence: The throttle cable is thin drawn steel which is tightly woven together to create one strong piece of cable. The cable is then inserted into a molded tubular casing to protect the wire from damage.
• Did Material Choice Impact Manufacturing: Steel cable is strong yet flexible and the easiest way to make steel cable is through drawing.
• Did Shape Impact Manufacturing: Cables and wires are easily drawn and then can be woven together to greatly increase the strenght.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- Since it is made out of steel it is likely that the cable will never break or need to be replaced.
  • Social- You never have to worry about the cable snapping and hitting someone because it is so strong.

Part: Key Piece

• Manufacturing Methods: Forged
• Evidence: The key piece is forged and is evident through the lines visible on the outer edges from the press pushing down on the material.
• Did Material Choice Impact Manufacturing: Thin steel pieces can be easily forged to create a desired shape.
• Did Shape Impact Manufacturing: Simple designs can be easily forged from sheets of steel.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- Forging is an economically sound way to make a piece compared to other methods.

Part: Muffler

• Manufacturing Methods:
  • Casing is die cast and drilled
  • Spring is drawn and tempered
• Evidence: The muffler is made by pouring liquefied metal into a mold. This evident by the shape of the piece. Then a drill is used to give it holes on the inner tower. Springs are made by hot winding a heated wire around a mandrel and then removing it immediately and then cooling it in oil. The spring must then be heat treated to make the spring strong and able to handle stress and return to original shape.
• Did Material Choice Impact Manufacturing: Yes, it is easy and quick to cast steel, and it is easy to draw and temper steel.
• Did Shape Impact Manufacturing: Thin walls of muffler would have been hard to mill and are more easily cast from a steel to gain these dimensions.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- Reduces noise pollution to the consumer and society.
  • Economic- Die casting is cheaper than other methods of production.

Part: Choke Plate

• Manufacturing Methods: Forged
• Evidence: The choke park is visibly forged. You can see flash on the round edges made by the press.
• Did Material Choice Impact Manufacturing: The thin steel pieces can be easily forged into formed.
• Did Shape Impact Manufacturing: Yes, simple 2 dimensional shapes are easy to forge.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- Forging is relatively inexpensive.
  • Societal- The choke ark makes the weed wacker easier to start.

Part: Kill Lever

• Manufacturing Methods: Forged steel, injection molded plastic
• Evidence: The kill lever is a thin piece of metal that could have easily been forged.
• Did Material Choice Impact Manufacturing: Yes, it is easy to forge steel into the kind of shape that is needed for this part.
• Did Shape Impact Manufacturing: Yes, small pieces of metal are easily forged from heated steel
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Forging is economical for a part with this type of geometry.

Part: Spark Plug

• Manufacturing Methods:
  • Rolled
  • Die casting ceramic
• Evidence: A spark plug is carefully machine rolled steel to make sure that it has precise dimensions and threads. This is evident through smooth lines around the outside of the spark plug, and the threads on the end. The ceramic casing on the plug is cast. The ceramic is then pressed onto the plug. This is evident by how tightly the ceramic sits around the plug.
• Did Material Choice Impact Manufacturing: Yes, you can make a mold of ceramic, and it is possible to roll metal to the shape of a spark plug and put thread on it.
• Did Shape Impact Manufacturing: Yes, it needed to be rolled to put the threads on it, and the shape of the ceramic needed to be cast because it is rather odd.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- This creates a good spark for the engine to start faster, and a good insulator to keep it safe.

Part: Spring shaft

• Manufacturing Methods: Drawn steel and tempered
• Evidence: The spring is made by multiple layers of tightly wound heated wire around each layer of spring and then immediately cooled in oil. The spring must then be heat treated to make the spring strong and able to handle stress and return to original shape. This is evident because we could see the different layers of wire.
• Did Material Choice Impact Manufacturing: Yes, to make steel wires you need to draw them.
• Did Shape Impact Manufacturing: Yes, to manipulate steel to a wire you must draw it. Solid steel that is milled into this shape would not be able to maintain the flexibility needed that is produced from multiple layers being wound together
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Drawing steel is much cheaper than trying to make the same part any other way.

Part: Shaft Housing

• Manufacturing Methods: Extruded, cut and then formed
• Evidence: The shaft is made from tubular piping that is cut to length (and then probably grinded to a finish) and then is bent into shape with a press and is used to protect the spring shaft.
• Did Material Choice Impact Manufacturing: Yes, metal made the choice of cutting and bending easy because they would both be quick and inexpensive.
• Did Shape Impact Manufacturing: Yes, since the desired shape was a bent pipe it only made sense to apply force to the pipe and bend it.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Social- Since it is a bent shaft it is easier to use than a straight shaft because of its angle to the ground.
  • Economical- These processes are more economical than say milling and it produces much less waste.

Part: Main Casing

• Manufacturing Methods: Injection molding
• Evidence: The casing is made utilizing injection molding and is evident through part lines and tapered edges throughout the housing.
• Did Material Choice Impact Manufacturing: Yes, because it is much cheaper and easier to mold plastic than do anything else with it.
• Did Shape Impact Manufacturing: Yes, because you needed a certain geometry that is easy to make with a mold.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- It helps dress up the machine. It also keeps heat away from the user. Using plastic makes it lighter than using a material such as metal.
  • Economic- Plastic is cheaper than metal

Part: Head Guard/ Protective shield

• Manufacturing Methods: Injection molding
• Evidence: The head guard is made by injection molding and is evident through reset marks in multiple areas.
• Did Material Choice Impact Manufacturing: Yes, the best way to shape plastic is through molding.
• Did Shape Impact Manufacturing: No since it is a fairly simple shape it could be made in a variety of ways however injection molding is the most cost effective way to make this part.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- It protects the consumer from projectiles, and being made of plastic makes it lighter than if it were made of metal.

Part: Elbow Spacer

• Manufacturing Methods: Die casting
• Evidence: The elbow spacer is made by die casting of aluminum and is evident through flashing marks at the ends of the piece and the parting lines.
• Did Material Choice Impact Manufacturing: Yes, it needed to be metal and could be small and had to be relatively strong so die casting could work.
• Did Shape Impact Manufacturing: Simple, small design can be easily mass produced with casting
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economical- Die casting is inexpensive on a large scale.

Part: Head Assembly

• Manufacturing Methods: Injection molding
• Evidence: The head is made by injection molding and is evident through reset markings and tapered edges.
• Did Material Choice Impact Manufacturing: Plastic in molds easily forms to complex shapes and is flexible so injection molding could easily make such a part.
• Did Shape Impact Manufacturing: Intricate detail within head that would be hard to be machined so it had to be molded.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal- Easily constructed for the consumer to be able to take apart and assemble again to adjust or change line. Being made of plastic makes it lighter.
  • Economic- Molding is cheap.

Part: Head spacer

• Manufacturing Methods: Forge
• Evidence: The spacer is a steel ring that is forged from a cut piece of metal. This is evident through the lines on the outer edge.
• Did Material Choice Impact Manufacturing: Yes, metal can be forged into the required shape easily so that was the obvious choice.
• Did Shape Impact Manufacturing: Yes, the desired shape allowed for the piece to be forged.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Economic- Forging is relatively cheap compared to other processes

Part: Screws

• Manufacturing Methods: Forge and rolled
• Evidence: Screws are forged steel and are evident through the fact they have flash. The threads are made from rolling.
• Did Material Choice Impact Manufacturing: Yes, the fact that they are made from metal allowed them to be made with a multitude of different processes the easiest of which being forging and rolling.
• Did Shape Impact Manufacturing: They need to be in one piece and are relatively complex so we had an idea that more than one process was used. The easiest combination to use would be forging and rolling.
• Influence of Global, Societal, Economic, Environmental Factors::
  • Societal-They hold the machine together.
  • Economic- This process of making screws is cheaper than casting and turning would be; which is another possibility of the way these screws were made.