Gate 3 - Product Analysis (Group 18)
Gate 3: Product Analysis
In Gate 2, the RC Helicopter was disassembled to its basic components. In Gate 3, we can now produce a detailed analysis of each individual component. This gate contains all the information gathered from the examination of components at the subsystem level.
This gate consists of the Project Management: Coordination Review - Cause for Corrective Action and the Product Archaeology: Product Evaluation - Component Summary, Product Analysis, Solid Modeled Assembly, Engineering Analysis and Design Revisions
Project Management: Coordination Review
Cause for Corrective Action
Overall, our group members work well together. Our time spent in and out of class or labs has made us closer friends. Our main channel of communication though is through Facebook, mainly because we can quickly share information with one another or set up meetings. Besides Facebook, we also keep contact with each other through text messages and emails.
During the course of this gate however, all of our group members had several mid-term examinations in other subjects. This prevented us from meeting up according to plan, and thus we had to produce this gate in a short period of time.
We realize that we had overlooked this problem in our initial stages of planning, and therefore will take extra precaution in the future.
As for the future, we might potentially face another time shortage to complete Gate 4. However, we will be making more changes to our plan for lab times and meetings as the Thanksgiving break is coming up, leaving us little time to complete Gate 4.
Product Archaeology: Product Evaluation
This section contains details regarding each component of the Syma S033G RC Helicopter which is the number of times the component is used in the product, the material the component is made of, the manufacturing process of the component, and the function of the component in the helicopter.
Component Complexity Scale:
1 – The component has simple geometric shapes and has no electrical components. The helicopter will work properly without this component.
2 - The components are a bit more complex and are important to the functionality of the helicopter. There is thought put into the designing of the component.
3 - The component is extremely complex/ the helicopter will not function without it
The functionality of this component is mainly there to protect the helicopter from collision and keeping the internal component intact. It also serves for aesthetic purposes. There is design on the shell for solely the purpose of aesthetics. This component encounters different type of environments, rain, cold, collision and windy environments. Even though it is not recommend for the helicopter to be used in extreme weathers, the component needs to be able to withstand these environments because users don’t always follow the instructions of a product intended usage.
The general shape of the shell is a thin hallow cone. The reason for a cone shape shell to protect the helicopter is for aerodynamic reason, reducing air resistance while flying for maximum speeds while flying. The shell is symmetrical, light weight, and made of plastic. It is primarily 3-D and roughly (11X4.5X5) inches in dimension. The shell weighs roughly a couple grams which is not heavy at all. It made of plastic and there is a specific reason for this. A driving factor in using plastic is for economic reason. Plastic is a bit cheaper to use then metal so it was more practical material to use. The component is coated with a blend of red, black and silver paint. The reason for this coloring is for aesthetic reason, trying to give it a sleep and cool look. The finishing of the shell is smooth and reflective, mainly for aesthetic reasons as well.
The component is most likely made from injection molding. Evidence that this part is made with injection molding are the parting lines in the middle bringing together three parts. Even though die casting process has parting lines, the shell is made from plastic which make die casting not a suitable choice for die casting. The injection molding is able to achieve more intricate shapes which the shell does have.
Component complexity : 1
The functionality of this component is to give stability to the helicopter while it is flying in the air. If a strong gust blows, the helicopter will not be blown away with the balancing bar.
The balancing bar is a long rod with two equal mass weights on each end of it. The bar is symmetrical for the most part except for the ball and socket joints in the middle which is inversed. The bar is a three dimensional shape with rough dimensions of (13x.75x.50) inches. The balancing bar is not heavy weighs roughly 500grams. The mean is composed mostly of plastic; the ends have a metal weight which is enclosed in plastic. This component has no real aesthetic purpose; it is more of a functionality component then for aesthetics. The bar is black; the reason for this is it that this component does not really have an emphasis for looking good so giving it a neutral color will draw attention away from it.
This part was most likely made from injection molding. There are visible signs of parting lines and riser marks on the component. Same with the reasoning behind the shell, this component is made mostly of plastic, making die casting not viable.
Component Complexity : 2
Lower Main Blade
The functionality of the blade is to lift the helicopter of the ground by rotating and creating lift. The blades are an extremely important component to the helicopter, without it the helicopter would not operate properly. So it needs to be able to withstand all sorts of conditions, wind, extreme weather, and water resistant.
The general shape of the blade is a long trapezoidal shape with a curvature. The blade is designed like this to maximized functionality, to lift of the floor. The blade is paired with a blade of the same shape that goes in the opposite direction. The blade is primarily a two dimensional component with a dimension of 10x1 inches. The blade is very light weight weighing only a couple of grams. The helicopter needs to be light weight to maximize flight efficiency so shaving off weight off each and every component adds up. The blades are made of plastic. Plastic is chosen because if the light weight properties also because it’s cheap. This component is here mainly for functionality and not for aesthetics. The blades are black and there is no specific reason for it. The surface finish of the blade is smooth mainly for aerodynamics reasons and minimizing air resistance.
Like the shell and the balancing bar, the blade is most likely made by using injection molding. It has parting lines and tapered lines. The blades being plastic also suggest that it’s made by injection molding.
Component Complexity : 2
Aluminum Tail bar
The function of this component is to connect the tail blades to the body of the helicopter and to give it its structure and shape. The tail bar needs to be sturdy and light weight so it can take a beating also is lightweight so the helicopter can fly.
The bar is a long hallow rod that is about thirteen inches in length with a diameter of half an inch. It is made of aluminum because aluminum is a very lightweight material. The bar is very lightweight as expected to make the helicopter as light as possible. The bar is coated with silver coat mainly for aesthetic reasons and to prevent corrosion of the aluminum.
The aluminum rod is most likely made by methods of drawing from a sheet of aluminum most likely. They cut a piece of the aluminum and then draw it to the shape they desire they harden it so it’s structurally stable. The reason why it is drawing because there are no signs of it being made by injection molding or die casting (tapering or riser marks). It would not make sense to make the rod by using all the rest of the methods either. You can’t use rolling to make a roll; even if you could it would be difficult.
Component complexity : 1
The frames function is to join all the components together, like the motor, circuit board, and the rods connecting to the blades. Same as the other parts the frame needs to be sturdy and collision resistant so it does not break.
The frame is symmetrical down the middle of its structure. It has no defining shape of its own being irregularly shaped. The frame is lightweight like the shell and the blades to maximize efficiency while flying. The frame is made of plastic and the decision behind it is to make it cheap as possible and as lightweight as it could be. There is no aesthetic consideration put into this because it’s an internal part where it’s hidden inside the helicopter.
This part was probably made by using injection molding. It has parting lines and tapered edges. Like the blade, it’s not feasible to using die cast because it’s not a metal material.
Component Complexity : 2
Main White gear
The function of the gear is to translate the motors kinetic energy into the rod connecting to the blades. It holds an important function in the helicopter, without it the helicopter would not fly. The gear performs in the helicopter with lot of moving parts. It needs to be durable and strong enough to withstand the heat that is generated with all the moving parts inside the helicopter.
The gear is a circular shape with uniform jagged edges. It is symmetrical with Y shape patterns spanning the radius. The gear has a diameter of 1.5 inches with a thickness of 1/6 inches. The gear is circular shaped because it would not work properly if it where another shape, say a square or a pentagon. It would not turn properly and then the helicopter wouldn’t work. The gear is made mostly of plastic with the middle cylinder being made of medal. The reason that the middle cylinder is made of plastic is because metal has a higher melting temperature then plastic. When the gear rubs against the rod it goes into it would generate heat, so by using metal it won’t melt. There isn’t much aesthetic consideration put into this part, because it’s an internal part so it’s hidden from plain view.
The gear is most likely made from injection molding and die casting. The plastic part is made from injection molding, there are rise marks on it and it being plastic makes it reasonable to say so. The metal part is made from die casting; it has a simple shape so die casting is possible.
Component Complexity : 1
The screw is meant to hold two components together. Its only function is to hold two components together.
The screw is a rod like shape with a cap on one side with threaded length. It is smymmetrical down the middle with the exception of the threading. It is a 3 dimensional component . the component is round because its easiler to fasten a round screw as opposed to a edged one. The screw is made with metal, its made with metal because it’s a stronger material and less prone to stripping when fastening it. It has a coating on it so it would not rust in contact with water.
The screw is made from a subtractive process where it takes a little rod and then grinds off the rod with a machine to give it its threads. Or it can be made with die casting because it is metal and relatively simple to die cast.
Component Complexity : 1
Solid Modeled Assembly
The components that we chose to represent as 3D models are the balance bar, main shaft, and blades. We chose these components because they physically interact with one another and they play an important role in allowing this helicopter to fly.
To create the 3D models, we used the AutoCAD 2011 version. We used this version because this was the version that we were familiar with as we had used it before in our Engineering Graphics class.
The interaction of the components is as shown.
A key component of the RC helicopter is its blades. The plays the essential role of creating lift for the helicopter to take off.
How much lift does the blades of the helicopter produce?
Diagram: The diagram shows the lift produced by the rotation of the blades
1. The blade stays rigid during flight 2. The mechanical energy transferred from the rotor to the blades if equal during flight. 3. Air friction and drag is negligible. 4. The helicopter is moving at its highest velocity.
Lift = A x σ x V
A = Area of blade
σ = Density of air
V = Induced velocity
When the blade is rotating, the natural movement of air changes around it. This flow of air is called an induced flow. The flow is directed downward, thus creating lift for the helicopter to rise in the air. The induced flow allows the helicopter to hover. When the user uses the remote control to direct the helicopter forward, the flow is directed opposite to the pitch angle, thus propelling it to move forward. under still wind conditions. Because the rotor system circulates the airflow down through the rotor disk, the rotational relative wind is modified by the induced flow.
During testing, the equation above will allow us to calculate the amount of lift produced due to the induced flow for one blade. Since our helicopter has 4 main blades, the total lift would be:
Lift = A x σ x V x 4
Therefore, the total lift produced by the RC helicopter can be calculated.
A major design revision that can be made is a change in the blade sets. The RC helicopter currently has two sets of blades, the upper blade set and the lower blade set. This is a common characteristic of a helicopter, where the blades are located above the main body of the helicopter. However, with the advancement of technology, a revision can be made where the blade sets are located at the sides of the helicopter instead of on top of it. These blades would be shorter than the current blades used but will rotate much more faster. This change will make the RC helicopter look more modern, and attract the interest of consumers.
From a social factor, the redesign will increase the interest of the consumer to purchase the RC helicopter. The user would also find it more easy to interact with the RC helicopter as the shorter blades will make it safer for the user to handle it when the helicopter is turned off.
From an economic factor, the size of the blades which would be smaller would reduce the cost of making the blades. The maintenance cost of the blades would also therefore be lower.
Another design revision would be increasing the capacity of the batteries of the helicopter. The current batteries need to be charged for 2 hours but it can only be used to fly the helicopter for 20 minutes before it needs to be charged again. This proves to be a problem with users who would like to fly and control the helicopter for a long time. Therefore, larger batteries with higher charge capacities should be used instead.
From a social factor, a positive outcome will result from this change as the user will feel more entertained when they get to fly the helicopter for a longer period of time.
From an environmental factor, a negative outcome may result from this change as more electrical energy will be needed to charge up the battery. Also, the larger batteries contain more chemicals, therefore if not disposed of properly, these chemicals may leak and harm the environment.
Finally, the gears of the helicopter should be redesigned so that more torque is transferred from the motor to the shaft and blades of the helicopter. The current gears work well, however we believe by adding more gears to the system the speed of the upper top blades, lower top blades and tail blades will increase.
From a social factor, this change will allow the user control the helicopter more easily in the air as this redesign would increase the speed and maneuverability of the RC helicopter.