Chart: Component Summary

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Gate 3: Coordination Review (Component Summary)

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Reverse Engineering Team Project: Homelite® VersaTool™ Line Trimmer (Group 29)

Table 3.1: Annotated List of Components' Attributes

Component Name & No.	Function	Material(s) Used in Manufacturing Component	Manufacturing Process	Functional or Cosmetic?	Component's Shape	Grade of Complexity	Image
1 Rear Housing	Protects the user from the heat generated by the engine unit during operation Channels the escape of heat through slits.	Heavy mold of plastic.	Molding process	Functional	Curvilinear; lacks considerable thickness in material	2: Mold manufacture does not involve excessive operations. Functionally imperative. No sub-components involved.	Figure 3.1: Click to view a higher resolution of the image.
2 Air Filter Kit	Separates particulate matter from air intake that may interfere with the effective and designed operation of the carburetor.	Filter consists of petroleum-derived product. Air Filter cover is constituted of plastic.	Chemical processes involving polymer cultivation for lightweight cellular byproduct (foam). For Air Filter cover, it is a process of plastic molding.	Functional	Cellular foam filter exhibits a rectangular prism. Can be regarded as either concave or convex; curvilinear.	2: For cellular filter, manufacture is comprised of chemical and mechanical processes. Critical to the functionality of the product. Of the Air Filter Kit, the cellular foam can construed as a sub-component, but in this category it resides alone.	Figure 3.2: Click to view a higher resolution of the image.
3 Torx Screws with Regular & Lock Washers (top image) Torx Screws (bottom image)	Torx screws with Regular and Lock washers fasten components to each other or onto the product. Lock washers enable fastener to secure to a position undergoing vigorous vibration more tightly than Regular washers provide.	Steel	Screws mass manufactured using "Thread Rolling" method. Washers produced via stamping mechanism.	Functional	Self-evident	1: Screws are mass manufactured, a process involving limited operations. Necessarily indispensable for the product to hold together. Torx Screws are attended by Regular and Lock washers.	Figure 3.3a: Click to view a higher resolution of the image. Figure 3.3b: Click to view a higher resolution of the image.
4 Crankcase Cover	Seals the Short Block	Steel	Steel casting for Crankcase cover. Extrusion and threading of holes.	Functional	Comparatively flat, rectangular plate with filleted edges. A cylindrical recess, and for threaded holes, 2 on the flank of each of the circle's two semi-circles.	2: Manufacture requiring casting involves methodical process. Functionally essential: The Short Block must be sealed to preclude any internal leaks the operation of the product. No sub-components involved.	Figure 3.4: Click to view a higher resolution of the image.
5 Fuel Tank	Provides a tank for storing needed fuel and filtering the fuel.	Plastic	Molded and then trimmed to proper shape.	Functional	Defies expression	2: Manufacturing process not difficult. Contribution to functionality somewhat important. No other parts.	Figure 3.5: Click to view a higher resolution of the image.
6 Exhaust Muffler	Muffles the intense sound waves generated by internal combustion process. Provides path for exhaust.	Aluminum Steel screws	Die casting for muffler encasing; cold working for steel screws, more than likely from austenitic steel.	Functional	Defies Expression	2: Manufacturing process not highly involved or time-consuming. Functionality somewhat important. No sub-components involved.	Figure 3.6: Click to view a higher resolution of the image.
7 Carburetor	Mixing chamber for fuel and air. Throttles mixture into Engine Head at a controlled rate.	Aluminum body with stainless steel plates, and rubber “bubble” used for manual fuel injection. Plastic choke handle Bronze throttling flap and fuel pipes.	Die casted, and then machined on all sides and surfaces.	Functional	Cubic	5: Materials very abundant, leading to a long manufacturing process. Functionality: Highly imperative. Contains many sub- components, including path for fuel.	Figure 3.7: Click to view a higher resolution of the image.
8 Carburetor Gasket	As the gasket to the carburetor, it seals the aperture covered by the gasket to the Heat Dam. Prevents interstitial leaks between connected components.	Asbestos, or a kindred compound	Molding process	Functional (arguably cosmetic as well, considering its unique rounded-edge, parallelogram-like figure)	Rounded-edge, parallelogram-like figure with two pairs of holes of two differing diameters, and a larger diameter at the center of the gasket.	2: Development of asbestos-constituting chemical compounds involves an extensive sequence of operations dealing with chemical engineering, followed by the molding mechanism whereby it achieves its intended shape. Functionally critical: Prevents catastrophic oil leaks from damaging internal components of the engine area. No other sub-components involved.	Figure 3.8: Click to view a higher resolution of the image.
9 Heat Dam	Provide buffer between carburetor and engine head. Prevents heat transfer to carburetor.	Dense plastic	Molded	Functional	Defies expression	2: Functionality only a precaution. Manufacturing process not highly intricate, but rapid. No sub-components involved.	Figure 3.9: Click to view a higher resolution of the image.
10 Piston/Connecting Rod Assembly	Provides compression and transmits mechanical energy to the shaft.	Aluminum	Milled This component requires high precision for smooth motion within engine head.	Functional	Piston: Cylindrical rod, which resembles a “Dog-bone” figure with both ends shaped as holes.	4: Long manufacturing process due to high precision requirements and its function being very critical to the product’s operation.	Figure 3.10: Click to view a higher resolution of the image.
11 Spark Plug	Delivers a spark to the combustion chamber, enabling ignition.	Aluminum	Casted	Functional	Cylindrical	3: Indispensable in terms of functionality. Manufacturing Process involves a series of operations. Corresponds with ignition coil.	Figure 3.11: Click to view a higher resolution of the image.
12 Engine Head (Cylinder)	Provides a chamber for combustion and path of motion for piston. Also has ports for fuel and exhaust.	Aluminum	Exterior: Die casting implemented in a two-piece form and merged together. Interior: High precision machining for piston; three threaded holes.	Functional	Rectangular fins used for heat dissipation. Cylindrical interior for seal with piston.	5: Very long/high precision manufacturing process. Function importance is very high. Exhaust and intake sub-components apparent (visible).	Figure 3.12: Click to view a higher resolution of the image.
13 Stringhead/Line Spool	Provides rotational motion for the line wound on the line spool.	Durable plastic	Molding process	Functional	Curvilinear, with a cylindrical, bulged protrusion at outer surface of the line spool.	2: Manufacturing process involves molding mechanism where minimal operations are necessary. Functionally critical in order to have the product deliver its designed end of scything grassy terrain with a rapidly gyrating line. No sub-components included in setup.	Figure 3.13: Click to view a higher resolution of the image.
14 Gear Head Assembly Moving parts of Gear Head Assembly http://www.youtube.com/watch?v=gF-kGbAXWwc	Convey rotational mechanical energy to the line spool via gyration of interlocking gears.	Steel, and much grease	Steel casting, followed by high-precision machining.	Functional	Cylindrical bases with angled teeth that serve as gears. Encasing of assembly forms hollow enclosure.	4: Manufacturing process requires high-precision machining. Indispensable in terms of functionality: The gears allow for the rotation of the line. The two interlocking gears are the functionally important sub-components of the assembly.	Figure 3.14: Click to view a higher resolution of the image.
15 Grass Deflector	Shields both the product and the user from stray grass.	Steel	Steel casting Extrusion, and threading for holes.	Both functional and cosmetic	Somewhat akin to a "deep-sea diver's" fin, but with a large-diameter hole extruded at the filleted tip for mounting to the line trimmer	3: Casting process and extrusion merit intricacy in the component's manufacture. Not entirely functionally important: The line trimmer can operate without having this secured to it. No visible sub-components.	Figure 3.15: Click to view a higher resolution of the image.
16 Ignition Coil (Magneto)	Provides electrical current to spark plug, thereby allowing spark plug to function.	Rubber insulators Plastic case Metallic coil	Undergoes a certain process performed in multiple steps.	Functional	Defies expression	3: Important component, as measured by functionality. Manufacturing process amounts to a comparatively swift operation. Corresponds to the spark plug.	Figure 3.16: Click to view a higher resolution of the image.
17 Clutch	Allows engine to idle without the line spool having to rotate.	Metal	Outer shell is die casted. Inner rings are machined.	Functional	Disk	2: Not as important functionally, and manufacturing process does not involve many operations.	Figure 3.17a: Click to view a higher resolution of the image. Figure 3.17b: Click to view a higher resolution of the image.
18 Rotor (Fly Wheel)	Provides initial rotation necessary for ignition. Magnetic component provides electric current for the spark plug.	Aluminum, with steel clips	Die casted Machined center hole for shaft fit, and groove for Woodruff Key.	Functional	Tenuous cylindrical disk with curved fins.	3: Manufacturing process complex due to fins. Very important in terms of functionality. Sub components not abundant.	Figure 3.18: Click to view a higher resolution of the image.
19 Starter Assembly Internal workings of Pull Cord configuration http://www.youtube.com/watch?v=Ow0RYIeccxQ	Provides for means of starting the line trimmer externally through user input.	Durable plastic, perhaps jute for the Pull Cord string, and cold-rolled steel for the Torx screws.	Molding process for the encasing and handle of Pull Cord. Threading and weaving for Pull Cord string. Mass manufacturing via "Thread Rolling" method for Torx screws.	Both functional and cosmetic	Defies expression	2: All components necessitate manufacturing mechanisms; however, they may vary among one another, do not prove very intricate and do not involve many machine operations. Functionally essential, for the user requires the Pull Cord to achieve ignition of the line trimmer. The solitary critical sub-component is the Pull Cord.	Figure 3.19: Click to view a higher resolution of the image.
20 Engine Shaft	Provides rotation and work transmitted from chemical energy.	Aluminum	Machined shoulder where bearings fit. Mainly machined.	Functional	Cylindrical	3: Serves a vital function to product. Manufacturing process involves multiple operations. No apparent sub-components.	Figure 3.20: Click to view a higher resolution of the image.
21 Flanged Washer	Enhances fastening.	Molded plastic	Molding mechanism is involved.	Functional	Flanged: self-explanatory	2: Manufacturing involves molding process. Component is functionally beneficial to fastening needs on the product. No sub-components.	Figure 3.21a: Click to view a higher resolution of the image. Figure 3.21b: Click to view a higher resolution of the image.
22 Short Block (Crankcase)	“The Main Frame” provides structure for mounting the Engine Head and the engine shaft. Provides compartment for rotation	Aluminum	Casting mold. Machined surfaces where Engine Head connects for sealing. Machined for low tolerance bearing fits, as well.	Functional	Rounded, curvilinear around myriad bends, and cylindrical, among other applicable adjectives.	3: Involves an in-depth manufacturing process. Important to functionality of product. Not too many sub-components directly involved, given it serves as a fixture for mounting components.	Figure 3.22: Click to view a higher resolution of the image.