Exceed RC Buggy Product analysis
Five pieces were chosen to be analyzed in more detail
The Exceed Hyperspeed RC car has a 2 stroke nitro-gas engine and shares the characteristics of a typical 2 stroke engine. The Engine’s primary function is to facilitate the combustion process and create shaft work. The flow associated with this component is air+fuel in and exhaust+shaft-work out. This component functions in a hot environment due to the combustion process. The general shape of the engine block is two cylinders placed together in an L-shape. With the exception on the exhaust connection the engine block is vertically symmetrical. This being one of the more complex components it is primarily 3 dimensional. The L shape of the engine is couple with its function because the piston corresponds to the vertical aspect and the drive shaft corresponds to the horizontal aspect. The engine weighs about 1/2 lb and is roughly 2 ¼” x ½” x 2” (L x W x H). The engine is made out of steel and has a brass sleeve in the piston chamber. Steel was used for the engine block because it can withstand heat without deforming. Brass was used for the sleeve because of its lower coefficient of friction. Aesthetics are not a large factor in the design of this engine because it is largely unseen during operation of the car. The engine is silver because it is made of steel. this component has a relatively rough surface finish in comparison to other parts on the car. The main geometry of the part was most likely made by a Die Cast due to the ridges in the center of the piece. The engine block would then have to go through several high accuracy CNC milling processes before it was completed. The part could not have been made purely by a Die Cast because of the ridges and small grooves present.
Our product uses a compression ignition engine which requires a glow plug to ignite the fuel. The glow plug has multiple functions: to provide heat for combustion and to function as a heat sink for the engine. The glow plug operates in an extremely hot environment because it is on top of the engine. The general shape of the glow plug is eight discs stacked around a cylinder. With the exception of the key slot for the glow starter this piece is horizontally and vertically symmetrical (when looking down at the car). This piece can be classified as a 2 dimensional component because of its high symmetry. It weighs about an ounce and has the cylindrical dimensions of roughly r = ⅘” and h = 1”. The stacked disc shape of the glow plug correlates to its function because it has maximum surface area to expel heat. The glow plug is mainly aluminum but has a copper male plug and a small wire of platinum. From a manufacturing perspective aluminum is easily machined and cheap. Platinum and Copper are necessary from a functional perspective for their conductive properties. This piece is a very distinguishable component because it sticks out of the car. It is silver because of the aluminum and has a fine surface finish. This piece was die cast and milled. The shape of the glow plug would make it extremely improbably that this piece was only die cast.
The exhaust manifold’s primary function is connecting the engine to the exhaust. The flow associated with the exhaust manifold is exhaust in from the engine and out to the exhaust. This component functions in a relatively hot environment due to its proximity to the engine. The general shape of the exhaust manifold is a hollow cylinder with one opening connected to a rectangular shaft connects to the engine. This piece is primarily 3 dimensional and lacks symmetry. This piece weighs roughly ½ ounce and has dimensions 1 ¼” x 1” x 1 ¼” (L x W x H). This piece is made from aluminum because of its ease of manufacturing and low cost. Much like the engine block this piece is unseen during operation and does not require attention to aesthetics. This piece like made by die casting the cylinder and shaft separately and welding them together. A finishing process smoothed down the weld on the rear side of the piece but weld marks are clearly visible along the side where the two connect. A milling process was used to create the grooves. A Die cast would be optimal because aluminum could be used.
There are two engine supports which connected the engine to the frame. The function of these pieces is to support the engine and hold it in place. The general shape one engine support is a rectangular box however finishing processes have shaved it down to maximize structural integrity and minimize material used. These pieces can be classified as 3 dimensional but can be understood also as 2 dimensional components Each one weighs about an ounce and has the dimensions 1” x ¼” x ¾” (L x W x H). The components shape is couple with its function because it needs a thinner top to connect to the engine and a wider base to connect to the frame. These pieces appear to be made of aluminum. Like the other aluminum pieces this is an economical and environmentally friendly material to use. Aesthetically this piece is similar to the exhaust manifold. This piece was Die Cast and then finished with a milling process to achieve the small grooves on its sides. The grooves and curves are too finite to be from a simple die cast process. The holes were drilled and tapped.
Piston Chamber Cover
The piston chamber cover functions to isolate the combustion process while allowing the pull start to begin the rotation of the piston. This functions in a high temperature environment because of its proximity to the engine. The general shape is thin hollow cylinder with a thin square piece around it. This piece is symmetrical except for the corner which protrudes to cover the pull start. The cover is about an ounce and has the dimensions ¼” x 1 ¼” x 1 ¼” (L x W x H). The cover’s shape allows it to seal the combustion chamber and connect to the pull start. This piece is made of aluminum and there is a copper sleeve in the center. Copper was used for the sleeve because of its low coefficient of friction and its contact with the starter shaft. The cover is primarily silver because it is made out of aluminum. This piece is internal and has no aesthetic purpose. The manufacturing process to make this piece was an extruded copper piece welded to a die cast aluminum plate. The hole were drilled and tapped for threads.
These five components are some of the most complex components in the Exceed Hyperspeed RC car. The metric that will be used for complexity is a 1 to 5 scale which accounts for the amount of manufacturing processes needed to make the piece and the amount of interactions each piece has with other pieces. A 1 would be a simple plastic support piece which was made by injection molding. The engine block is a 5 because of its intricate geometry and interactions. The glow plug is a 3 because of its geometry. The exhaust manifold is also a 3. The engine supports are also a 3. The support cover is a 4 because of the manufacturing processes needed to make it.