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Smartech Magic Wheel

Executive Summary

The purpose of this project was to dissect a product in order to apply principles learned in our MAE 277 lectures. The product that our group chose was the Smartech Magic

Wheel gas powered RC truck. Originally, the task to dissect the truck seemed daunting, however, through use of analytic processes and well documented disassembly procedures,

we were able to learn more about its system and subsystem interactions, material composition, and gained better insight into how the parts were fabricated and assembled.

Once fully disassembled, we analyzed the use of materials, how they were made, part geometry and their connections. We could also more easily identify how user interactions

affect subsystems (ex. User manipulates steering controls -> steering servo changes wheel orientation). In an attempt to improve the products functionality, user interaction,

and ease of fabrication, we devised some design revisions of which the benefits could be further researched.

With the completion of the system and component analysis we reassembled the truck. Using our assembly process as a procedural reference, we had little difficulty with the

reassembly. However, there were a few complications, including: the bulging of one of the plastic protective plates (due to poor placement) and the fracture of the steering

servos mounting bracket. We included further design revisions as a result of these complications found.

Through knowledge gained from conducting a thorough analysis of the Smartech Magic Wheel, we were able to better explain our product’s complexities, as well as a proposed

design revision, to our MAE 277 class. Our group met regularly in order to accomplish each gates’ goals while also observing the deadlines. In conclusion, this project

reinforced the material taught in lecture and will give us further insight into future applications.

Figure 0.1 Side View of Product Figure 0.2 Front View of Product
caption caption

Gate 1

The fist gate includes research of the background of the product and performance of initial assessment, as well as completion of a work proposal and management proposal.

Work Proposal

Reverse engineering of the Smartech Magic Wheel will require not only the dissection of the truck as a whole but an initial analysis of the overall system and of the

components individually. Before the group begins to disassemble the truck we will need to come up with a systematic approach to doing so because of the fact that the

components are all connected and interact with each other, so naturally starting with the most complex and integrated part would be unwise. Also it would be helpful to

have all of the necessary tools on-hand that will be needed to proceed with the actual dissection.

The tools needed are shown in the table below:
Figure 1.1
Figure 1.1 Listing and visualization of the necessary assembly/disassembly tools.
For an easier and successful disassembly the components to be taken out first should be those not connected to too many parts and after freeing will simplify the work

needed to take out any other part(s). Therefore we will need to locate the components whose bracings are exposed and those that are concealed or blocked. With these in

mind we can figure how to go about effectively dissecting the truck.

First the fuel lines from the fuel tank should be disconnected from all other components and the throttle rod detached from the servo motor. This will make things less

tangled and help to maintain some organization when detaching individual parts from the truck and will require only the use of simple pliers to loosen up a single nut

connecting the throttle rod to the servo motor. Next the section of plastic framing beneath the chassis should be removed by unscrewing the bolts connecting it to the

truck with a PH1 screwdriver. After this is done the PH1 screwdriver can then be used to take out all of the screws located on the underside of the chassis, this should

dislodge most of the components used to drive the system not including the suspension or tires. The two main parts that will be left after this are the two identical servo

motors, one placed upright on top of the chassis, and one upside down half way through a cut out part of the chassis, both are braced by four screws placed on the top

part of the motors plastic casing. This should complete the removal of all of the engines parts and main part of the truck, any other connects found during the dissection

may require the use of a smaller Philips head screwdriver, a cross wrench, or hexagonal wrenches. In addition, the disassembly of the individual parts will most likely

require a smaller sized screwdriver such as a Phillips #0 or Phillips #00 due to the fact that some of the individual parts use smaller screws.

The main obstacle in the dissection of the truck is the plastic frame since it concealed several screws that connects the components to the chassis and should be simple

to remove unless the connection it has to the rest of the frame is more complex than it reveals itself to be from its outer appearance. The system as a whole, including

the engine parts all located on the truck’s chassis, should be easy to remove and disassemble as it mostly consists of clearly exposed screws and unless there are

additional hidden braces should take no longer than thirty minutes. Once off of the chassis further effort will be needed to detach some of the members from each other and

extra tools may be needed such as the needle nose pliers. The time it will take for the individual components to be dissected is pending because they are hard to analyze

in the arrangement that they are currently in.

Below is a chart of the skills and shortcomings of each group member:
Figure 1.2
List of each group member's strengths and weaknesses.
Our group will need to research the functions and components of a small gasoline engine as none of our members are very experienced in this field. This will help us

identify the different parts included in our product and what purposes those parts have in making the Magic Wheel effectively run. Once we add this knowledge to what we

already know it will then be possible to relate it to what we discover within the truck after dissecting it and successfully gain a better understanding for how the truck

works and why it was designed the way it was.

Management Profile

To keep up with required deadlines, maintain a stable group relationship, and ensure the production of the best work possible by each member of our group certain

responsibilities were handed out to each group member in accordance with their own personal skills and what they proved themselves to be the best at. Each person was

given a title reflecting their own abilities and each title comes with a set of responsibilities that need to be met in order to fabricate the best work possible. Aaron

was given the title of project manager and it is his job to be in charge of starting, ending, and intermediating group meetings. The responsibility of making sure

deadlines are met also falls upon him, so if one or more members of the group are lagging behind it is his responsibility to recognize this and come up with appropriate

measures to ensure the completion of their part of the project in correspondence with the deadline. If there is an internal conflict within the group it is also his job

to resolve it as quickly as possible to ensure that group productivity is maintained. Alex was given the title of group stenographer, and with his title comes the

responsibility of writing down the ideas that group members talk about during meetings. When the group decides to write any assignment as a team rather than splitting the

assignment into parts and combining those parts when each member is finished with it, it is Alex’s job as the group stenographer to type the collective thoughts of

everyone which then becomes the report/assignment. Bryan was given the title of project intermediary. His role in the group is contact with the professors, TA’s, or

anyone else that needs contacting with questions, comments, or concerns from the group in order to progress through our assignment. He is also in charge of contacting

group members to inform them of any meeting time changes or important updates of any kind. Anthony was given the title of Technical Virtuoso and it is his duty to lead

the team in all disassembly, reassembly, and technical analysis of our project. Anthony has the most technical experience as well as the most hands on experience with

both CAD and basic electronics deeming him the most capable to lead the dissection of our product.

As stated above Bryan Lam is our main source of contact between both group members and instructors. Main source of contact between Bryan and all others will be his

University at Buffalo email address Any and all questions/comments regarding the project and all that entails should be sent directly to him via

this contact.

Our group has already convened and decided that Tuesday night is the best time to meet. The meetings are scheduled to take place every week until the end of the

semester. Group meetings are to take place in the Red Jacket quadrangle, building six, room 495, at 7:30 PM, but are subject to change based on the work required and

group member availability. Weekly group meetings are not limited to a certain amount of time and can carry into the hours of the night if necessary because all group

members have minimal classes the next morning. We have also designated Saturday from 6 to 11 PM to be our emergency meeting time. If an emergency meeting needs to be

called the project manger will alert the project intermediary and the other group members will be contacted promptly and the place of meeting will then be discussed and

the meeting will take place. This additional meeting will ensure the ability to meet deadlines. If someone is having trouble with their part of the project there is

ample time for them to receive help from all other group members to ensure it is done on time. We have also prepared a Calendar with important dates highlighted to ensure

we know exactly when they are due and what they entail.

Figure 1.3
Calendars outlining due dates

Product Archaeology

Material Profile

Our initial investigation of Smartech’s Magic Wheel 1:8 scale RC truck was limited to a simple visual inspection where we identified three main materials: Plastic, metal,

and rubber. Also, there are two fluids necessary for use of this product. Nitro gas is the fuel used to power the small gas engine. Oil is also necessary for the general

operation of the engine. It is also used as a lubricant for the gears in drive system, and is required for the ideal performance of the oil-filled suspension system.

The majority of the structural construction is made of various types of plastics, with the thinnest being used as the trucks aesthetic shell. The front and rear bumper, the

wheel hubs, the wishbone suspension arms, and the suspension cylinders all appear to be made of a more durable plastic, suitable for handing aggressive use. There are also

various connector pieces made of both plastic and metal, including: Screws, nuts, hex bolts, and washers.

Commonly used metal connector pieces are comprised of steel, or a steel alloy. It’s also likely that the piston rods for the suspension system, and the drive shaft, are

also made out of steel. The metal chassis, however, looks to be made of aluminum. The advantages of using aluminum versus steel for the chassis is that aluminum provides

a lower cost, yet durable, light weight alternative as the trucks main structure. It is also the platform on which the product is built. Aluminum is a soft metal, yet

durable enough to act as a shield against damage to the internal components.

Without disassembling the model, it is difficult to conduct a thorough examination of the internal components shielded by the body. However, we know that the main

operating components encased within include: a small-gas engine, a drive system, a steering servo motor, a fuel reservoir and a signal receiver. There may be more unseen,

but until a more complete examination is conducted we will make assumptions on only the previously listed components. The fuel reservoir is made from a plastic that is

non-reactive with the nitro fuel. A thin plastic tube, or rubber hose, may be used to supply fuel to the engine from the reservoir. The signal receiver may be comprised

of a plastic casing and a combination of other materials necessary for the receiver’s basic circuitry and corresponding power supply. In addition to the steering servo,

the drive system and the engine are assumed to be made out of an assortment of metal and plastic components used in simple mechanical systems.

User Interaction Profile

Getting started:

In order to properly use this product, these are the necessary preliminary steps required.

• First, 4 AA batteries must be inserted into the receiver box on the truck and 8 AA batteries must be inserted into the signal transmitter (remote controller).

• Prior to installing the servo motors, calibration can be checked by first setting the servo to its zero position, indicated on the motor, and then activate the receiver and transmitter in succession. The servo motors are now in their zero position. Turn off the receiver and transmitter, and install the servos.

• Oil should be previously applied to gears during the construction of the product, as it will greatly improve mechanical performance of the RC truck and minimize potential part failure.

• Add desired amount of fuel to the fuel reservoir, with care taken to not spill the fuel onto any exposed parts and then prime the starter.

• Prior to starting the engine, be sure the carburetor is in the neutral position. Turn on the receiver and transmitter in succession. Next, in one fluid motion, pull the pull start cable to start the engine.

• To shut down the engine and turn off the RC truck, simply press the stall switch, located on the engine, and turn off the receiver and transmitter in succession.


Control of this vehicle is handled solely by use of the control transmitter. Controls are intuitive and easy to use. They are limited to: Forward and backward movement,

right and left turns, brake, and dual speed control (Hi-Low).

• Turning right is as simple as rotating the wheel shaped dial on the transmitter clockwise. The more the dial is rotated, the tighter the resulting turn will be.

• Turning left is done similarly, by rotating the dial to the counterclockwise. The more it is rotated, the tighter the resulting turn will be.

• The speed is adjusted by use of a three stage trigger system. The three stages can be achieved by pulling the trigger closer to the grip (bending your finger). In the first or neutral position is the brake. The RC truck must be started in the neutral position to prevent accidents. The second trigger position allows the truck to travel at half speed whereas the third position will provide full power to the engine.

• To take the truck into reverse all the user has to do is push his/her finger forward on the trigger.

Regular maintenance is required for the lifetime use of this product. Maintenance of a nitro fueled RC vehicle can be laborious and should be considered prior to its

purchase. The main item that requires consistent cleaning and maintenance is the small-gas motor. Oil and fuel is burned as a result of the small-gas engine’s combustion

method, and the exhaust expelled deposits itself on the vehicle. This must be cleaned consistently to maintain the efficiency of the vehicle. The engine also requires

that excess fuel be burned off, as well as the oil to be flushed out and replaced. The oil filled suspension system must have adequate oil levels to be dependable

dampers. Prior and after each use, it is recommended that oil be applied to any exposed gears and bearings to help shield against dirt and corrosion.

Product Alternative Profile

There are many products on the market that are comparable to the Smartech Magic Wheel 1:8 scale RC truck. Some are similar in most aspects, like the Traxxas T-Maxx, which

is also a 1:8 scale gas powered RC truck. Others try to accomplish the same entertainment goals, with slight differences in power and mechanical design, like HPI’s Savage

Flux, which is an RC truck that utilizes an electric brushless motor.

The Traxxas T-Maxx and the Smartech Magic Wheel are nearly identical. There is some speculation that the Magic Wheel is a legal copy of the T-Maxx, but uses less than

ideal materials and a lower degree of production quality, at the benefit of a much lower price. The majority of components found on the Magic Wheel are interchangeable with

the T-Maxx, as well as with most other upgradeable parts. This feature gives the Smartech Magic Wheel the versatility of customization and repair options. The Traxxas

T-Maxx has a lower-end price range of about $350.00, which is the maximum that you will pay for a Smartech Magic Wheel. The Magic Wheel starts at as low as $150.00, and is

an alluringly low price for beginner RC hobbyists.

The Smartech Magic Wheel also shares similarities with equal sized battery operated RC trucks, such as the Savage Flux. However, there are inherent disadvantages and

advantages with gas power versus battery power. One advantage that gas power has over battery power is in the duration of use. With gar power, one can easily refill the

tank with fuel for continued use. But with battery powered RC trucks, one must recharge or replace a battery once the power is low. Also with gas engines, the power

outputted will be consistent through the duration of use. As opposed to battery power, where the power output diminishes with time as the battery drains. One advantage

that electric motors have over gas engines is in the time it takes for each system to apply torque. Electric motors have near instantaneous application of torque whereas

gas motors take time to spool up and engage the clutch. This makes changing directions and shifting gears more difficult for gas powered systems than electric. Another

inherent advantage to electric power is the lower degree of mechanical wear and fatigue. Gas powered RC trucks usually have a higher performance rating and are in use

for longer durations of time. This creates a potentially more aggressive environment of use.

Product Comparison:

To provide an easier look at these comparisons, please observe Table 1 on the following page. Here you will find each product, some key features, and their market price

range. All prices were researched from various online shopping sources, but the overall price ranges include items varying from: previously used to new, and from starter

kits to more advanced sets. It should also be noted that the dimensions of many used hobby vehicles may be altered in some way. The dimensions and weights given are of

un-altered, store bought vehicles.

Figure 1.4
Listing of alternative RC car models, their price range, and their top speeds

Development Profile

The Smartech Magic Wheel was developed in the early 2000s with key concerns both economic and global. When the product was being developed the economy was stable and

allowed for the creation of products that would be able to be sold to consumers with an excess of money. Even if the economy was good there were still economic factors that

effected the development of the Magic Wheel. The choice of materials in the Magic Wheel was essential due to the comparable strength of plastics and metals, but the cost of

plastics is vastly less than the comparable metals. Also a key concern was that there was another identical model of the vehicle made by another company, but the cost of the

competitor was much higher than that of the Magic Wheel.

Globally the Magic Wheel is targeted for Western consumers because in Western culture the aesthetics of the Magic Wheel are almost identical to that of the typical monster

truck seen in events held in the Western world. Along with being targeted to people in the Western hemisphere the Magic Wheel has taken into consideration the climate and

terrain typical to that of North America where the product would most likely be sold. The use of the various components such as the suspension, tires, transmission, drive

train and the gasoline motor are all such that it would be optimal to be used in various climates and terrain typical to that of North America.

Overall the products’ development was there to directly compete with the more expensive models of the off road remote controlled truck, and to allow consumers to purchase

the product for significantly less money than the competitor. The vehicle is also there to allow close consumer interaction that allows for the safe replication of certain

actions unobtainable by normal consumers for their entertainment. In society the vehicle is there to allow consumers to purchase a cheaper model vehicle while portraying the

image that they have spent more money.

Usage Profile

The intended use for the product is for the consumer to use the vehicle recreationally for their entertainment and enjoyment. This product would used at home because the

price point that the product has target those of the average consumer and the areas of distribution usually include hobby stores and by company promotions that use them for

advertising. The use of these easy to access distribution methods further targets the use by consumers.

This product allows consumers and users to utilize the product in many areas including track situations and off-road situations. Its job is to connect the user with the

vehicle while giving them the sensation that they are in the vehicle performing the given commands. It allows for the opportunity to those who would use the vehicle as if

they were operating the vehicle without the possibility of injury or major damage to the vehicle which would be non-repairable.

Energy Profile

Figure 1.5
Diagram of the presumed energy flow found in the Magic Wheel
In figure 5 it shows that the types of energy utilized in the product are chemical, electrical and mechanical forms. It also shows that the energy forms are brought into

the vehicle by a chemical battery and potential chemical energy found in gasoline. These two forms of energy are transformed into rotational shaft energy because of the

combustion energy captured by the gasoline motor. From the gasoline motor the rotational shaft energy is directly transferred into the transmission; the transmission has a

series of gears that form precise gear ratios that either increase or decrease the number of revolutions that the output rotating shaft may achieve. From this modified

rotational shaft energy the energy is directly transferred into the drive train which at its simplest form will split the energy from the single rotational shaft energy

input to four rotational shaft energy outputs to each of the four wheels. The wheels finally transfer that energy to the surface on which the vehicle is traveling to create

translational energy that moves the vehicle forward.

Complexity Profile

There are three major components that are utilized by this vehicle to make it move; the gasoline motor, the transmission, and the drive train. The gasoline motor utilizes

combustion to create energy; the gasoline combines with air at a certain ratio that is optimal for combustion. This combustion allows for the expansion of a cylinder that

creates rotational energy to a shaft. The transmission takes the energy from the gasoline engine and transfers it to a series of gears that transfer the energy to each other

until the desire output is achieved. Finally the drive train takes the output of the transmission and split it evenly to each of the four wheels.

Of the three said components the transmission is the most complex due to the nature of using gears to achieve certain gear ratios as well as the fact that it is a two speed

automatic transmission, the automatic feature of the transmission allows the transmission to shift through the gears without the need of user interaction to specifically

change gears. The automatic shifting must happen at predefined moments that is determined by the transmission itself, and then comes the process of shifting gears. Shifting

gears causes the main gear to mesh with a different gear while disengaging from the previous gear, and to do so without destroying the gears is a very complex operation.

The creation of the gears used in the transmission is also a very intricate process. They must be calculated so that the power output of the motor is optimized so that the

energy is transferred with minimal power loss. The motor is the second most complex due to the use of combustion. Since combustion is a controlled explosion the mixture of

air and gasoline must be perfect because if it were off it would either not combust which would not release the desired amount of energy, or combust too much and destroy the

motor in an uncontrolled explosion. Lastly the drive train is the least complex because the splitting of energy is easily achieved through simple gearing.

For the components that create the system their interactions are seemingly linear as the energy is directly transferred to the next component in the system. It can be

said that the energy is transferred linearly because there is no power loss between the interactions of the individual systems.

Gate 2

Cause For Corrective Action

The plan created previously in gate one Has had both positive and negative aspects. As a whole our group has encountered only a few downfalls in our original management

proposal including poor time management, and a fewer amount of group meetings than originally planned. Some of the reasons our plan has worked so well include our accurate

descriptions of both our flaws and our strengths, our simplification of the dis-assembly process, our research into what tools are needed for which parts, our research done to

identify each individual part, and the ability to work together effectively as a group.


Our group only encountered two problems with our original work proposal for dissection of the product. The first was poor time management skills. The problem arose with the

construction of the calendars with only primary deadlines highlighted like the due date of each gate of the product. The group should have come together to talk about each of

the gates, broken each of them up into sections to be done at separate times, and decided when each section of each gate should be completed by to keep on schedule. This

newly improved "sectioned off" plan should then have been placed on the calendar to keep the project on a stricter schedule. The calendar should also have been printed out

and a copy should have been placed in the room of each group member so as to remind each of us of the deadlines, because the biggest problem encountered with the calendar was

never having it right in front of us to see when gates were due. The second shortcoming was the small amount of group meetings. Our group had planned to meet once a week

every Tuesday to keep on track with the project, however with everyone's schedule it was hard to keep the group meeting at the same time causing the group meetings to be

skipped on occasion. To keep a tighter schedule and make sure at least one group meeting will take place each week we should have come up with several times a week when all

group members were free so that if our original meeting date was canceled due to unforeseen events it could have easily been replaced by another day of the same week. This

would have allowed our group much more time together to talk about the project, work on the project, and meet deadlines easier and with more efficiency.


Our group's original plan had many positive aspects. The first reason for our success was the accurate description of personal capabilities that everyone gave. Because each

group member was honest with both their strengths and weaknesses we were able to create a plan and divide jobs accordingly leading to a much easier time with each step of pour

dissection process. For example Alex has the most knowledge of remote controlled vehicles and small combustion engines whereas Bryan had little experience with both remote

controlled cars and electronics, so when the actual dissection took place Alex was placed as head of the dissection while Bryan was placed in charge of keeping record of what

parts came off the car and which screws came from each part. The simplification of the dis-assembly process that was laid out in gate one by our group also aided in

dissection of our product. When writing the work proposal we were sure to take a very close look at what would need to be taken off first to make the removal of parts easier

on us as well as keeping track of where the parts went on the car. In our work proposal we stated that the removal of the gas lines, throttle rod, and break rod should come

first because it would "make things less tangled and help to maintain some organization when detaching individual parts from the truck". Our research into what each

individual part actually was as well as which tools would be necessary for removal of those parts also made the dissection easier and free of complications. Fortunately for

our group the RC truck came with an instruction manual on how to build it because it was a build-it-yourself car that was built by Aaron's father seven years ago. As a group

we went through the instructions to not only each be able to identify all the pieces, but also know which tools would be necessary to remove them from the chassis. The final,

and by far most influential reason for our success was the ability of our group to work together effectively and efficiently. From our groups formation we were set up with a

project team that was more than capable of this project. Only two group members had known each other previously so when the group came together to work that is exactly what

was done. Instead of friends fooling around and getting little work done our group worked as a well oiled machine for each meeting. We also each have individual traits that

aid in the group productivity. For example Aaron showed right away that he was the group leader organizing the meetings and keeping everyone on schedule while Bryan showed

his aptitude for communication, and Alex showed a keen sense for the technical writing process. Jobs were able to be distributed according to everyone's natural strengths

leading to a strong and very functional group.

Product Dissection

Figure 2.1
Exploded view of fully dissected RC vehicle

Dissection Difficulty Scale

Difficulty Rating # of Required Tools Time Required for step # of fasteners attaching subsystem General Description Example
caption One Less Than A Minute One to Two The components’ attachments are clearly visible and easily accessible. Intuitive detachment process. A single user can complete this detachment alone. Detachment of the wheels
caption One-Two One to Four Minutes Three to Five The components’ attachments can be seen, but are not out in the open. Accessibility may include one obstruction. Detachment process may require repositioning of product in order to complete. Assistance may be necessary for the user during this step. Detaching suspension system from chassis
caption One-Three Over Five Minutes Six and Up The components’ attachments are hard to see and are hidden from plain view. Accessibility is difficult due to multiple components/subsystems obstructing the user’s ability to connect the component. Detachment process requires the user to reposition the product one or more times during the step. Assistance is recommended for the user to complete this step. Detachment of the transmission from chassis as well as other components

Dissection Table

Step Number Difficulty Rating Description Picture of step Picture of step Picture of step
1: Removal of Plastic Shell caption We first had to remove four cotter pins by hand and lift the shell off vertically taking care not to damage the antenna. caption caption caption
2: Removal of Wheels caption We removed four 5/16 inch nuts (one per wheel) with a 5/16 inch nut driver, and after the nut was removed the wheel just pulled right off. caption N/A N/A
3: Disconnection of fuel hoses & throttle rod caption We first used our hands to disconnect the fuel hose from both the engine and exhaust. There were no fasteners holding it in place, the hoses were held on solely by the constrictive force of the rubber. We then used needle nosed pliers to detach the nut that connected the throttle rod to the throttle control servo motor. caption N/A N/A
4:Disconnection of Brake Rod caption We removed the brake assembly by using a 1/16 inch allen key to loosen the set screw on the rod connected to the disk brake. caption N/A N/A
5: Removal of Front Bumper and Protective Plate caption We removed four 1 inch machine head screws with a #2 Philips head screwdriver from the front bumper. With the removal of the final screw we discovered a spacer that we were unable to see without removal of the bumper. We then removed ten countersunk screws with a #2 Philips head screwdriver that were holding the front plate to the chassis. Upon removal of the plate another spacer was discovered that we were unable to see when the front plate was attached. We assume that the spacer had the purpose of maintaining stability of the drive system and suspension structure. caption caption N/A
6: Removal of Back Bumper as well as Middle/Back Protective Plates caption We removed the middle plate by taking off eight countersunk screws with the same #2 Philips head screwdriver. We then removed eight countersunk screws with a #2 Philips head screwdriver that were holding the rear plate to the chassis. Upon removal of the plate another spacer was discovered that we were unable to see when the front plate was attached. We assume that the spacer had the purpose of maintaining stability of the drive system and suspension structure. We then removed four 1 inch machine head screws with a #2 Philips head screwdriver from the rear bumper. With the removal of the final screw we discovered a spacer that we were unable to see without removal of the bumper. caption caption caption
7: Removal of Support Beams caption We removed the two plastic support beams by taking off four 1/2 inch machine head screws with the same #2 Philips head screwdriver. These screws secured the protective plates, the support beams, and the transmission gearbox to the chassis. caption N/A N/A
8: Removal of Electronic Components caption We first removed the signal receiver. To do so we had to remove two small countersunk screws with our #2 Philips head screwdriver from the chassis. We then removed the throttle servo by taking off four 1/2 inch machine head screws utilizing our #2 Philips head screwdriver which fastened the servo to two arched supports that were later removed. We then removed the steering servo by first detaching the servo armature from the rest of the steering system by the removal of one 1/2 inch countersunk screw with a #2 Philips head screwdriver. Then four more screws holding the servo to the chassis were removed. They were driven through rubber grommets and fastened to small supports on the opposite side of the chassis. We Finally removed the power supply simply by the removal of two small screws driven into the chassis using our #2 Philips head screwdriver. caption caption caption
9: Removal of the Transmission caption In order to remove the transmission the throttle servo support had to be removed first. Two screws similar to the support beam screws were removed with our #2 Philips head screwdriver. With the removal of the throttle servo support the transmission was easily removed by hand. caption caption N/A
10: Removal of the Engine caption First we removed the exhaust by the removal of one screw and nut, which attached it to the chassis. This freed up the exhaust to be simply pulled off of the engine. The engine was then removed by unscrewing four 1/2 inch machine head screws from the chassis using our #2 Philips head screwdriver. Please note that these screws had a much higher thread count than all other removed so far. caption caption N/A
11: Removal of the Suspension Systems caption We first removed the front end suspension system via the removal of six countersunk screws. Two of which secured aluminum pivots necessary for the steering system, where the other four secured the suspension system to the chassis. Finally the rear suspension system was removed by taking off four similar screws from the chassis. caption caption caption

Documentation of Subsystems

Control system to Electrical system:

This is a signal connection using radio waves to provide a method for the user to interact with and control the vehicle. You need this connection because without a method of

controlling the vehicle there would be no movement of the vehicle therefore the user would not be able to use the vehicle for the purpose that it was made for. This radio

signal has a global concern because around the world there are regulations on the bandwidth that can be used and the specific nature that they can be used, such as how GSM

cell phone frequencies are only used for voice and data transmissions. Due to the nature of radio frequencies and how the product functions the strength of the transmitter

should be able to span around 100 meters or so the distance that the user would still be able to clearly see and operate the vehicle. Also, this connection type is necessary;

anything other than a wireless type of connection would severely limit the mobility and dynamic capabilities of the product.

Electrical system to Steering system:

There is a physical connection between the servo and the steering arm, which transfers electrical energy into mechanical energy. This allows for effective steering of the

systemand displays an economic concern through its mixture of metal and plastic parts. Steering is crucial to the operation of the vehicle because without the utilization of

steering control there would no method of control the vehicles direction of movement. The plastic is a cheaper yet still effective replacement but the more crucial parts such

as joints or components handling larger loads remain as metal to resist breaking down from the vehicles highly dynamic operation. The layout currently of the steering serving

is parallel to the steering mechanism, but it can be placed directly onto the steering system to reduce the complexity of the connection.

Electrical system to Engine system:

This is a physical connection in the form of a thin metal throttle rod controlled by a servo and adjusting the intake of fuel in the combustion engine ,which is a transfer of

mechanical energy from electrical energy, and as a result it alters the speed of the vehicle. This throttle arm is necessary to the function of the vehicle due to the fact

that without the throttle arm there would be no forward of the vehicle, therefore the purpose of the vehicle would not be met. The throttle arm is made of metal because if it

were to be made of a rigid material there would be possibility that the shocks and vibrations would alter the state at which the throttle is set at. Whereas the metal rod

currently being used has enough ductility to absorb the shocks and vibrations that could possibility alter its state. This connection's layout cannot be changed because it

they were to be moved the connection would be more complicated than the original linear connection.

Engine system to Transmission:

This is a physical connection using gears from the engine to the transmission, this takes the rotational energy produced by the engine and directly transfers it to the

transmission. They need to be connected in order to transfer the energy from converted from the engine to the transmission, without this connection there would be no movement

of the vehicle. The transmission utilizes plastic gears over metal ones as a result of economic concern of cost and furthermore the gears are lighter which helps in vehicle

acceleration, maneuverability, and efficiency. While metal gears are more precise in their dimensions it is not worth the extra cost of the gears, when the individual

subsystems can be moved in order achieve optimal contact. This connection could also be direct from the engine system to the transmission via a direct rod connection to get

rid of the gears connecting the two systems currently, but there would need to be changes the transmission to include a fly wheel and the other components that were taken out

from changing the connection.

Transmission to Wheels:

This is a physical connection consisting of ball joints, differentials, and drive shafts which allow for the movement of rotational energy between the transmission and the

wheels finally allowing for the translational motion of the vehicle. The drive shafts are all plastic as they aren’t responsible for supporting very much load and need only

to transfer rotational energy. This is a lighter and cheaper alternative, but the ball joints are metal to give a more precise and smooth transition between components

permitting better performance and durability. This connection would not be optimally changed from its original layout.

Gate 3

This gate is a detailed analysis of our dissected product at the component and subsystem level.

Cause For Corrective Action

In the last gate (gate 2) our group has headed in a good direction with many positive aspects and only a few shortcomings that were making finishing assignments and gates on

time a little difficult. We had a problem keeping up with group meetings and making sure at least one was held each week. We also had a problem with poor time management.

The gates weren't being sectioned off accordingly and finished on a schedule; they were being saved until a week before the due date and then we were forced to rush leading to

poor development of the gate and consequently leading to unsatisfactory grades. To fix these problems the group came together and made up a calendar that was to be printed

out by each group member and placed somewhere in each members room for quick reference. On the calender we highlighted meeting days in green, sections of the gates in yellow,

and gate due dates in red. The visual of the calender helps us to accurately gauge how much time we had left and tells us if we are keeping on track with our schedule. Each

gate was sectioned off into three parts, and each part was evenly distributed across the time we had to finish each gate. As for what is part of each section; the group is to

decide what each section entails at the very start of each gate. For example on the due date of gate three the group will meet that day and decide what each section of the

next gate (gate 4) entails, and each section will be "due" for us on the yellow dates shown on the calendars below. The formation of this calendar will hopefully correct our

problem of time management, however the answer will be unclear until gate three is over and we can fully assess the situation in hindsight. As far as all group members can

see we have no unresolved challenges to fix, save for the possibility of still having poor time management based on the outcome of the calendar experiment, we are working

efficiently as a group and have no problems since 10/31/11 of meeting at least once a week and making those meetings productive. The proposed calendars for the rest of the

semester are shown below and the colors are explained on them to make it clear to all group members wheat they mean at a glance.

Figure 3.1 Figure 3.2
caption caption
Proposed Calendars Proposed Calendars

Component Summary

Smartech Magic Wheel 1/8 Scale RC Truck

Part # Component Picture Function Material Manufacturing Process # Of Times Used
083041 Wheel Wheel123.jpg Rotation in order to provide forward movement. Polystyrene plastic rims.

Rubber composite tire tread.

Injection molding (for both rubber and plastic) Four
None Found Suspension System Suspension123.jpg
  • Absorb outside forces acting upon the vehicle
  • Structurally supports truck body
The system is comprised of many individual parts most of which are made of Black ABS polymer plastic.

It is held together and connected by steel fasteners and steel ball-in-socket joints.

Injection molding for individual plastic pieces.

Turning for the fasteners that attached the pieces.

083064 Steering Arms SteeringArms123.jpg Move the wheels left/right and control the car's movement.
  • Please note that the steering arms were shown attached to the suspension system to easily see how they affect the steering of the car.
There are Black ABS polymer plastic rods as well as brass and steel rods connected to those rods. The plastic rods were turned as well as milled to gain their final shape.

The brass and steel rods were also turned.

083034 Bumpers Bumpers123.jpg To protect the front and back of the car and its components from both front and rear impacts. Black ABS polymer plastic Injection molding Twice
083035 Connecting Boards Connectingboards123.jpg Connect bumpers to the suspension system & provide rigidity. Black ABS polymer plastic Injection Molding Twice
083052 Chassis Chassis123.jpg Provide protection and support for all internal components of the vehicle. Aluminum Stamping with a machine press for the oddly shaped holes.

Drilling for the countersunk screw holes.

083051 Stiffeners Stiffeners123.jpg Provide rigidity to the front and back crash barriers. Steel Stamping by machine press. Twice
083002 Front crash barrier Front crash barrier123.jpg Provide a barrier for frontal impact. Black ABS polymer plastic Injection molding for main shape and drilling for the screw holes. Once
083001 Rear crash barrier Rear crash barrier123.jpg Provide a barrier for rear impact. Black ABS polymer plastic Injection molding for main shape and drilling for the screw holes. Once
083022 Bottom Protective Rods Bprotectiverods123.jpg Support the transmission in place as well as act as a barrier against outside elements trying to act on the transmission system. Black ABS polymer plastic Injection molding Twice
083036 Protective Board Protectiveboard123.jpg Provide extra protection against outside elements. Black ABS polymer plastic Injection molding Once
083027 Battery box Batbox123.jpg Contain the battery supply for both the servo motors and the signal receiver. Black ABS polymer plastic Injection molding with a sanding finish. Once
083026 Receiver Receiver123.jpg Receive the signal from the remote control transmitter and outputs the signal in a manner that the servos can understand. Black ABS polymer plastics with a sanding finish for the box containing the receiver. There are many internal components to the receiver whose material properties are unknown to us. The plastic case was made by injection molding. The holes in the housing were made by drilling. Once
None found Throttle servo Throttle servo123.jpg Control fuel intake of the motor. Alternatively controls the braking operation. Both operations are mechanical in nature. Black ABS polymer plastic shell. Various unknown mechanical and electrical parts are contained inside. The plastic case was made by injection molding. The holes in the housing were made by drilling. Once
None found Steering servo Steering servo123.jpg Controls the steering of the vehicle by actuating the steering arm accordingly when an input signal is received. Black ABS polymer plastic shell. Various unknown mechanical and electrical parts are contained inside. The plastic case was made by injection molding. The holes in the housing were made by drilling. Once
083016 Fuel tank Fuel tank123.jpg Contain and dispense the fuel that the motor will eventually utilize. Clear ABS polymer plastic Injection molding and drilling for the holes present. Once
None found Engine Engine123.jpg Converts potential energy of fuel into rotational energy to provide forward movement for the car. Grey & black cast iron Die casting in three separate pieces that were then joined with fasteners. individual parts were machined for intricate details and finishing. Once
083007 Transmission Transmission123.jpg Modify the rotational energy from the engine to be distributed to the wheels. Black ABS polymer plastic for the shell

Brass gears inside of the shell Fiberglass disk brake Various other metal parts

Injection molding for the shell

Gears were made by subtractive machining processes

None found Exhaust pipe Exhaust pipe123.jpg Safely divert hot exhaust fumes as well as other harmful substances outside of the vehicle and away from crucial components. Black ABS polymer plastic The main shell and the rubber gasket were made by injection molding and the intricate aluminum fasteners were made by turning and milling. Once
None found Plastic body Plasticbody123.jpg Provide aesthetics to the vehicle to increase sales. High impact polystyrene plastic sheeting Vacuum forming Once

Component Assessment

Complexity Matrix

In order to adequately assess the complexity of each individual component we chose to break the complexity into three factors. Those factors include the manufacturing

processes needed to make the component, the part geometry, and the function of the component. These three factors will be explained in detail in the following tables below.

Components assessed will be given a complexity rating for each category where the color green stands for simple/no complexity, the color yellow stands for medium complexity, and

the color red stands for high complexity.

Figure 3.3
Function Complexity Scale

Figure 3.4
Process Complexity Scale

Figure 3.5
Material Complexity Scale

Component Assessment

Component 1 Body
I) Component specifications
Serial number: None found
Weight: 1/4 lb
II) Component function
The body provides two main functions. It provides protection to the internal components from damage and debris as well as providing aesthetic appeal to the truck. This component functions in a high drag, high debris environment depending on the environmental operating conditions. This component does nothing for any of the other components besides providing protection. Human interaction and energy is required for the movement (removal) of the component from the vehicle.
III) Component form
This component resembles the shape of a truck you would see anywhere on the road. It is symmetric down the center plane of its length, and is a thin 3 dimensional shell. The component measures 17.5" in length, 6" in width, and 6" in height. This components shape was most likely designed to provide a smaller amount of drag than would on the car without it, as well as providing some protection to the inner working parts of the vehicle. The component is made from high impact polystyrene plastic sheeting most likely due to the simplistic nature of its forming process, its relative low cost to produce,and its extremely low weight. The lost cost aids in the consumers ability to buy the product and the low weight doesn't weigh the car down unnecessarily. This component was designed to look like a monster truck to attract the attention of the consumer and increase their chance of purchasing the product. The color of the component is black and it has decals on the side much like that of a real-life monster truck to again attract more attention to it and aid it visual appeal. The surface finish is very fine and shiny to aid even more in the visual appeal of the truck, just like a well waxed truck in real life. The finish of the component is purely for aesthetic reasons.
IV) Component manufacturing processes
This part was made using vacuum forming. We were able to conclude that vacuum forming was used to create this component because of the shape and material that was chosen to create the part. Any other method of production would cause unnecessary difficulties, therefore vacuum forming was used. Because the engineers in charge of this product needed a light weight material in a complex shape vacuum forming was most likely chosen based on these needs. The decision to make this component out of the material chosen was most heavily influenced by economic factors. Because the material is extremely inexpensive there would be low cost to produce it. The shape of the component was most heavily influenced by societal factors, because the people interested in buying and putting together this car would most likely be men and therefore enjoy the aesthetic look of a truck.
V) Component complexity
Figure 3.6
Factor Complexity
Manufacturing process caption
Form caption
Function caption
Component 2 Chassis
I) Component specifications
Serial number: 083052
Weight: approximately 1/4 lb
II) Component function
The chassis serves to be a platform for many of the other components to be a fixed to such as the engine and the transmission. It also provides the bulk of the structural support for the vehicle itself. It has cutouts for many of the components to fit through so that it can pass through in order for those components to do their functions.
III) Component form
The chassis is basically a rectangular piece of metal and is symmetrical along its center length plane save for the different holes cut into it. It measures 10” in length, 6.25” in width and .125” in height. The shape of the chassis is there to optimize the amount of components that can be secured onto its surface while giving them a rigid base to be supported on. The component is made from aluminum which is a light metal that is stronger than plastic while being much less hefty than steel. Aluminum was used since it is a rigid material that is able to take a lot of abuse and its weight is light enough that it won’t impact the vehicle’s performance as well as being much less expensive than steel. The aluminum has a brushed finish which gives it more aesthetic appeal when considering that the vehicle will operate in environments that may scratch the bare aluminum without any finishes.
IV) Component manufacturing processes
The chassis was made using a stamping process that cuts out the overall shape and the intricate features within the aluminum chassis, also there was a drilling operation that countersunk many of the holes and drilled many of the holes also. Stamping was used because the one side of the edges is rounded while the other side has a lifted edge major signs that it was stamped using compressive forces. Stamping is the best operation to create the chassis since casting the aluminum would need liquid aluminum and a mold to be casted. If the chassis was cast there is a high possibility that the part would have structural defects due to its thickness. The chassis could have also been machined using a CNC mill, but this process would take a very long time and would require more skilled labor to program the machine. Also the milling machine requires milling bits that wear over time and since they wear it would also add to the cost of making the chassis. Overall the cost for casting and machining the chassis greatly outweighs the stamping process’ cost. Stamping was also ideal to create the chassis because the part doesn’t have any major features along its thickness making it generally two dimensional; ideal to be stamped.
V) Component complexity
Figure 3.7
Factor Complexity
Manufacturing process caption
Form caption
Function caption
Component 3 Wheel
I) Component specifications
Serial number: 0830340
Weight: approximately 1/4 lb
II) Component function
The wheel’s main function is to transmit the rotational energy from the car’s engine to the ground upon which the vehicle is on. However since the wheels give the car motion they can also be manipulated in order to steer the vehicle’s direction in which it moves. In the energy flow of the vehicle the wheels come last. It is last since all of the previous functions create or modify the energy. Being last in the flow allows it to utilize all of the energy given to it from the other functions, therefore it is able to transmit all of its energy to the surface that it travels on. Also since the wheels are in the last part of the flow it can be seen that it must be in constant contact with the surface that it travels, this in turn means that it must be exposed to the environment of the surface; the surface can be wet, dry, dusty, rough, etc.
III) Component form
The general shape of the wheels is cylindrical; cylinders have axial symmetry and are three dimensional objects. Since the vehicle has to transmit rotational energy into translational energy it is optimal to have cylindrical wheels since cylinders always keep tangential contact with the surface in which they rest on. The wheels are approximately 6.5" in diameter and are made from both ABS polymer plastic and rubber. They chose to use plastic and rubber for the wheels for two specific reasons. They used plastic since it would be easily and quickly made into the wheel’s rim, and rubber was used for the tires tread since it has a high coefficient of friction and also allows for compression allowing the wheels to have a higher line of action. Economically it was advisable to use plastic instead of metal since the cost of plastic is much less than that of metal. Societal factors showed that having a metallic finish on plastic would catch the eye as much as chromed metal rims. To have the metallic finish was aesthetic to show its relation to regular sized car tires, this is purely aesthetic. But the tires have raised treads as their finish in order to create more pronounced line of actions for the wheels; this is both an aesthetic and a functional finish for the tread.
IV) Component manufacturing processes
The wheels were made using an injection molding machine, since there were riser marks and seams from the mold pieces coming together. Since both plastic and rubber are able to be made by injection molding it was easy to assume they were made that way since the parts needed to be mass produced without excessive worry about dimensional accuracy. Also the shape is quite simple it would be easy to create a mold that would be able to create the two parts of the wheel.
V) Component complexity
Figure 3.8
Factor Complexity
Manufacturing process caption
Form caption
Function caption
Component 4 Bumper
I) Component specifications
Serial number: 083034
Weight: approximately 1/16 lb
II) Component function
The bumper is a simple yet effective component whose main function is to protect the truck from damage caused by collision with outside objects. While this is its only purpose, it is an essential one. While the truck itself is in action, most of its energy is focused in frontward or backward motion along its length. This means that, with the exception of the tires, the majority of outside forces will act directly on the outermost, front and rear faces of the truck. The bumper serves as a barrier that absorbs these forces and prevents damage or shock to the internal components. This component is effective in any type of environment since it is composed of a single durable material.
III) Component form
The bumper is composed of two parallel triangular braces that attach to the frame of the vehicles suspension and on the outer side of the triangles two horizontal and parallel rods span the majority of the width of the truck. While it is made up of different rods, the bumper as whole is solid and has symmetry across the vertical plane through the length of the vehicle. This is a 3-dimensional component whose dimensions are 6" in length, 2.5" in width, and 2.25" in height. Since this component’s function is to prevent damage to the rest of the truck, its placement and shape is important, its vertical placement must start at the height of the chassis so that small debris can easily go under the truck but obstacles high enough to hit the truck will be stopped or muffled by the bumper, in addition the bumper must be wide enough to cover all of the important components as well as long enough to leave crunch space in order to successfully absorb any hit or shock on the truck. The bumper is made out of black ABS polymer plastic and weighs approximately 1/16 lb . This material, being sturdy yet slightly flexible, is essential to the functionality of the part. It is able to take many impacts without wearing down and is flexible enough to absorb them without harming any other components. Also it is a cheap material that is easily manufactured which is important from an economic standpoint. Additionally, a global concern would be the temperature differences in various parts of the world, it is important that the bumper does not become too rigid in colder temperatures while at the same time retains a certain amount of stiffness in higher temperatures. This component has a rough slightly bumpy surface; there is no need to make it smooth or shiny since it will experience some wearing due to its function. It is black in color so as to match the rest of the vehicle and avoid being aesthetically awkward. With the exception of its shape, there is no functional reason for its appearance.
IV) Component manufacturing processes
The bumper was created by injection molding. This is evident because of the observed seam lines on the outside of the part. Also this type of plastic is a common material used in this type of process and the shape of the component is more easily made through the molding process compared to any other process. Economically this a smart decision since it is cost effective and is easier for the mass production of the part, as opposed to other processes such as subtractive manufacturing whose precision is not needed, is more expensive, takes longer, and is not practical for this type of material.
V) Component complexity
Figure 3.9
Factor Complexity
Manufacturing process caption
Form caption
Function caption
Component 5 Engine
I) Component specifications
Serial number: none found
Weight: approximately 1.75 lb
II) Component function
The engine is the main component of drive within the vehicle, or in other words is what creates the mechanical energy required for the truck to move. The engine also controls the amount of energy that is outputted by using various amounts of fuel at a time. By means of combustion, the engine takes the potential energy stored in the liquid fuels and turns it into thermal and rotational kinetic energy and must be in a well-ventilated environment as to avoid being over heated.
III) Component form
This component is in the form of a miniature single cylinder engine with the output gear coming out of one end horizontally and an air intake/filter extending above it and on the opposite side a small pull start used to get it running. While not perfect, it does display some symmetry down the vertical plane of its length and measures 4.5" in length, 3" in width, and 3.25" in height. While the shape of the engine is mainly just a result of encompassing its various parts, it does utilize a multitude of long parallel cuts in its metallic shell that allows the component to cool more rapidly from the generation of thermal energy as a result of the combustion of the fuel. This is one of the heavier parts because of the materials used weighing about 1.75 lb. Other than the air intake and pull start, the engine is made of grey and black cast iron who’s sturdiness and strength is needed to contain and control the explosive properties of the fuel during the combustion process. Even though there weren’t necessarily any manufacturing decisions that influenced the choice of material, there were in fact economic factors in play. While a higher quality engine could be made using other metals such as steel, cast iron is preferred due to the lower cost and the fact that there is little impact to the performance of the vehicle. Because of the fact that this is an internal and hidden component whose only function is to provide the driving force for the vehicle it has little to no aesthetic purpose. The colors and surface finishes of this component are there because of the properties of the materials and do not serve a functional or aesthetic purpose with the exception of the output gear whose precision is needed for a smooth transfer of energy.

IV) Component manufacturing processes
The engine consists of three main parts that were die casted for their general shape and machined to produce the more detailed parts that required more precision. The three parts were then joined by several screws creating one rigid body. The material itself and its shape served as the main evidence in how it was manufactured since it requires this method in order to be made and shaped in the way that it is. It would be hard or impossible to produce ridges and unique shapes found on the engine using other methods of manufacturing. The production of this component is based mainly on its material properties and performance requirements leaving little opportunity for global, economic, societal, or environmental factors to influence how it is manufactured.
V) Component complexity
Figure 3.10
Factor Complexity
Manufacturing process caption
Form caption
Function caption
Component 6 Transmission
I) Component specifications
Serial number: 083007
Weight: approximately 1.0 lb
II) Component function
Modifies the energy imported from the engine and outputs the energy accordingly to the drive shaft by use of a geared system which transfers the torque based on the input energy level. This component also performs a braking function, by mechanically pinching a brake disk that is connected to the transmission shaft. The operating environment of the transmission is that of a moderately high heat and high vibration environment.
III) Component form
The transmission case is oblong shaped and non-axially symmetrical. It is three dimensional and when viewed from the side, it is triangular with rounded points. The rounded points sheathe the internal gear system necessary for operation. Its dimensions are approximately 2.93” in length, 2.83” in width, 3.25” in height, and weighs about 1 lb. The case of the transmission is made out of injected molded black ABS plastic. The internal gears are believed to be brass or cast steel, with a break-away gear made from a softer metal or plastic. It should also be mentioned that the transmission case is filled with oil, to prevent gear deformation due to friction. As per the plastic case, we believe manufacturing decisions impacted the form due to the ease of which injection molding can create unique contours with minimal production cost and time. There are a few specific material properties that are necessary for the transmission to function properly. For the case they include: A low thermal conductivity and moderate strength and hardness to prevent fracture. Economic factors such as material cost and cost due fabrication processes influenced the decision to use ABS plastic as opposed to a metal such as aluminum. Aesthetically, the transmission isn’t very eye pleasing. It is mostly functional as the plastic case has a black matte finish resulting from the molding process.
IV) Component manufacturing processes
The main manufacturing method used to make the plastic case is injection molding. This process creates two halves that will be fastened together. Once molded, a drill press is used to drill and tap the connection holes. If the internal gears are metallic in nature, then they were either machined by milling, or die-cast. If they are made of plastic, then the most common way to make plastic gears is by injection molding. We believe that the shape of the parts in the transmission impact the manufacturing process, whereas the material chosen for each part was greater determined by its functional purpose. In order to prevent environmental waste and increase production efficiency, ideal manufacturing methods is essential. The choice to use a 5-axis mill to create each part would be wasteful in material and production cost.
V) Component complexity
Figure 3.11
Factor Complexity
Manufacturing process caption
Form caption
Function caption
Component 7 Fuel tank
I) Component specifications
Serial number: 083016
Weight: approximately 0.125lb
II) Component function
The fuel tank provides two functions to the vehicle. It provides a place to hold the fuel that the car takes to run as well was houses a primer for easier starting of the engine. This component runs in an environment inside of the vehicles shell and extremely close to the engine, which causes it to work in a hot area where it is subjected to vigorous movements based on the movement of the vehicle and the terrain that it is traversing. This component is responsible for providing the fuel to the engine, and without it the car would not be able to function. However the engine is the only component that relies on the fuel tank so if you were to find another fuel source for the car the fuel tank could be removed. Human interaction is required to use the primer which helps start the engine, and after the engine is started it is not the fuel tank that pumps fuel into the engine. The engine itself sucks the fuel out of the fuel tank making the only functions that it performs the holding of the fuel and the housing of the primer.
III) Component form
This component is mostly rectangular in shape however it has a curve cut out of it so as to not get too close to the engine and either melt or combust the fuel prematurely. For easier visualization the cross sectional area of the fuel tank will be shown in figure 1 below.
Figure 3.12
Cross-Sectional View of Fuel Tank
The fuel tank is three dimensional and has symmetry in the way that if you were to take any cross sectional area across its length they would be the same. The component measures 3" in length, 2.25" in width, and 2.75" in height if it were a three dimensional rectangular cube. The radius of the cutout is 1". The fuel tank is shaped in this manor to keep it out of the throttle rods way as well as keeping the fuel farther away from the engine. If there were no cutout in the component the throttle rod would have to travel through the fuel tank which would make the tank a much more complex component, and the engineers in charge of designing the tank and throttle rod would have to deal with numerous more obstacles including making sure the tank wouldn't leak and the fuel rod wouldn't be affected by having to move through the tank. The component is made from a clear form of what we believe is ABS polymer plastic. We believe that it was designed to be clear to let the user see the amount of fuel in the tank and be able to judge if he/she needed to add more fuel or not to the tank. This material was chosen for the fuel tank because it is very strong for its weight and its ability to be clear/opaque. It is not necessary for the fuel tank to be made from a strong material such as this, however it is a smart decision because if the fuel tank were to break or even spring a leak next to the combusting engine the results could be disastrous. This material was influenced economically by its inexpensive price for its functionality and was influenced by society by its strength which lets it perform its job without high risk of malfunction. And as said before malfunction of the fuel tank could cause unwanted combustion of fuel destroying the car and displeasing the consumer/owner. The only aesthetic property of the component is the fact that it is clear. It makes it much easier for the consumer to see when refueling is necessary. The component has a smooth surface finish on the outside which led us to believe it has a smooth finish on the inside so as not to add any unwanted debris to the fuel inside. This finish is purely functional because if any debris from the fuel tank got into the fuel and eventually into the engine it could potentially destroy the car.
IV) Component manufacturing processes
This part was made using two manufacturing processes. The first, as well as main, method was by injection molding. We found small amounts of flash on the outside of the fuel tank which allowed us to deduce that injection molding was the way that the component was formed. There are also holes in the tank that had to be made by drilling. Their material choice of ABS polymer plastic definitely influenced their decision to use injection molding because plastic can easily be shaped using this method at a relatively low cost. The fact that this component is a simple geometric shape also influenced the decision of the manufacturing method because simple geometric shapes such as this can be made with a simple mold decreasing cost of production which is also one of the economic factors influencing the decision on how to make this product, because the lower product cost means more profit for the company.
V) Component complexity
Figure 3.13
Factor Complexity
Manufacturing process caption
Form caption
Function caption

Solid Modeled Assembly

The individual parts can be downloaded by clicking this link. The components were modeled using Pro-Engineer Wildfire, so it is suggested that while viewing the files that specific program is used. We are providing the link to download the files from another website because we could not get them to directly upload to the wiki.

Group 21 CAD Files

Individual Components

  • please note that not all individual components are shown here, only a select few were chosen to be shown separately from the exploded view assembly.
Figure 3.14
Part Name 3D Model
Transmission caption
Disk-brake caption
Gear caption
Drive-shaft Components caption
Ball-joint caption

Assembly Views

  • Please note that each assembly view will be shown again in an exploded view corresponding with the same view number in the next section.
Figure 3.15
Assembly View # Assembly View Exploded Assembly View
#1 caption caption
#2 caption caption
#3 caption caption
#4 caption caption
#5 caption caption

Engineering Analysis

Problem statement

The gearing inside of the transmission is a very complicated process that involves intricate movements and precisely designed gears to transfer the torque and engine speed to

the tires. The engineering analysis would be used in the design of the vehicle’s transmission to maximize the power band and the speed offered by the engine. The problem

statement involved with this analysis would be to optimize the gear ratios to provide maximum performance while keeping the parts within reasonable stresses.


Figure 3.16 Figure 3.17 Figure 3.17
caption caption caption
Possible chart/data Diagram/layout of gears & alignment Sample gear
In this particular problem the diagram would include many different gears that are available to be used in the system each with different properties, but the most important

details would come along with the number teeth that each gear has, the radius of the gear and the type of teeth that the gears have. There would also be a diagram of how the

transmission’s layout would be for the calculations; showing how each of the gears interact with each other and how. In figure 2.1 it shows various gears that the engineer may

use for reference when choosing gears, and in figure 2.2 it displays how the basic transmission layout that could be used for these calculations.


In order to be able to find the calculations the gears would be simple spur gears with uniform teeth geometry to maximize power transfer and ease of calculations. Also the

calculations would be limited to two driver gears of two varying dimensions and two driven gears. But the largest driver gear and smallest driven gear would be a pair, while the

smaller driver gear and the larger driven gear would be a pair also. There would also be a gear attached to the shaft that holds the driven gears to be paired with another

driven gear, but this driver gear transfers the power into the transmission itself. Also to simplify the calculations further the amount of friction acting on the gears

interactions would be negligible, and there would be no power losses in the system. With these last assumptions the equations used hold true for every case possible.

Governing Equations


The governing equations used in gear calculations find the ratio between two gears, in the given equations the subscript B is the driven gear, and the subscript A is the driver

gear. For example NB would be the number of teeth on the driven gear while NA would be the number of teeth on the driver gear, and if you were to divide Nb by Na you would get

the gear ratio; number of revolutions the driver gear would have to rotate to get one full revolution of the driven gear. If the gear ratio is greater than 1 then the driven

gear rotates slower than the driver, while if it were less than 1 it the driven would rotate faster than the driver.


In the calculations the engineer would have to find the gear ratios between AB, CD, EF, BD and BF. The need for BD and BF are so that you can find the number of revolutions

that the driven would need to do in order to get one revolution of the driver, this is because the two gear pairs are on the same shaft but they have different driven gears. And

to find the final gear ratio you would multiply the gear ratios in the order that they lay. For example the final gear ratio between A and C would be the gear ratios of AB, BD

and DC multiplied, and the final gear ratio between A and E would be the ratios of AB, BF and FE multiplied together also. Also included in the gear ratio equation is the

relationship between torques, since the engineer would know his engine torque and would want to know the amount of torque at the driven gear it would be as simple as multiplying

the torque by the final gear ratios to find the amount of torque transmitted along that energy path.

Sample calculations:


Solutions Check

In the solution check the engineer would analyze his calculations to make sure that he numbers make sense for what was given, he would be checking for units if he had been

calculating for his torque. But otherwise he would be checking his final gear ratios to make sure they had been within what was being designed, since the ratio has no units the

ratios would be the only thing to be checked within this area.


In the discussion area of the process the engineer would have to analyze all of his calculations to his problem statement, since the problem statement was to optimize the

gearing used in the transmission he would want to see that he had a higher gear ratio so that the car would have good acceleration, while also having a lower gear ratio that

gives the vehicle its maximum speed that it could travel. If after this is complete and he finds that they have reasonable gear ratios it would be ultimately advisable for him

or her to create a mockup of the transmission in order to see if their gear ratios would be best for the vehicle.

Design Revisions

Revision #1

Gas Tank:

In an attempt to improve the gas tanks overall production cost efficiency, fuel capacity, and ease of use for the customer, these are the following changes to the gas tank that we have proposed:
  • Raise the overall height of the gas tank by 1 inch, to increase the total fuel capacity
  • Change the cap design from the current torsion spring loaded lid to a screw on cap.
  • Change the primer from the current spring loaded button to a more simplistic diaphragm primer
Although there will be a potential increase in production cost of each gas tank, due to a more lengthy fabrication process, there will be a decrease in the amount of overall

parts needed for the tanks fabrication. Through utilizing the benefits of injection molding, the threading for the cap and the diaphragm primer fixture can be created at the

same time as the rest of the tank, without the need for additional tapping. By designing the top of the gas tank cap and the diaphragm primer to be shear with the top of the

fuel tank, we can maximize the height in which the tank can be raised.

Revision #2


In this revision we will be analyzing the suspension system. Currently the design has two oil-filled shocks attached to a suspension arm which has zero lateral movement. We

wish to change this to one shock per wheel as the apparent need for two shocks per wheel seems unnecessary and part consuming. This reduction in parts is economically

beneficial through the reduction in total production cost of parts and molds necessary to create them, as well as reduction in the cost of initial assembly. Through

simplification of the suspension system design, we also aim to facilitate the replacement of parts by the consumer. The redesign will contain larger suspension arms and easier

to access connections. With the enlarged shocks in view, the RC truck will take on a “tough” look, that will likely appeal to RC enthusiasts.

Revision #3


The current connection system for the wheels to the wheel hub by use of a bolt and nylon lock nut is sufficient. The design offers a simple connection that can facilitate

versatility in wheel choice based on terrain. However, the wheels and the rims packaged with the truck are in need of redesign as they offer little in versatility.

The packaged wheels contain a large treaded, air filled, rubber tire that is adhered to a chrome painted ABS plastic rim. This wheel type is beneficial for operation in rough

terrain, however it proves to be inefficient while operated on flat terrain, such as asphalt. Due to the adhesion of the tire to the rim, exchanging the tire type to a street

tire is a challenge. Therefore, in our redesign of the wheel, we wish to address this issue by creating a rim that will allow for the exchange of different tire treads.

This redesign will spawn new product families of treads and rim types that will appeal to those who seek maximum customization in their RC vehicle. The versatility in tire

types can range from thick to thin and from high-density foam to large treaded rubber to meet the demands of the operating conditions.

Concerning the fabrication process of the new rim design, a simple lip near the edge of the rim would suffice as a tire fastening device. Once a tire sleeve is slid on, the lip

would prevent it from sliding off unless desired. This addition to the rim design can be made by simply altering the current rim mold.

Gate 4

Cause For Corrective Action

We are proud to say that our group has overcome all of the problems previously identified in our earlier gates. The proposed calendars from gate three that were placed in each

group member's room were a complete success. Once we implemented the use of the calendars our group meetings happened on schedule at least once a week, and gate four was

sectioned off accordingly making the completion of it much easier as we were not rushing to finish the night before it was due. During group meetings we worked with little

distraction and worked well as a team taking criticism and ideas from each other quite well with no arguments ever arising. Each group member did his respective parts of the

gate on time, and all group members agree that the work was divided evenly and fairly among us. Since gate three, we have encountered no problems with anything relating to the

project or working well together as a group. This tells us that we, as a group, have figured out how to address problems before they arise and come to conclusions about how to

avoid them altogether.

Product Reassembly

Complexity Scale

Difficulty Rating # of Required Tools Time Required for step # of fasteners attaching subsystem General Description Example
caption One Less Than A Minute One to Two The components’ attachments are clearly visible and easily accessible. Intuitive attachment process. A single user can complete this attachment alone. Attachment of the wheels
caption One-Two One to Four Minutes Three to Five The components’ attachments can be seen, but are not out in the open. Accessibility may include one obstruction. Attachment process may require repositioning of product in order to complete. Assistance may be necessary for the user during this step. Installing suspension system onto chassis
caption One-Three Over Five Minutes Six and Up The components’ attachments are hard to see and are hidden from plain view. Accessibility is difficult due to multiple components/subsystems obstructing the user’s ability to connect the component. Attachment process requires the user to reposition the product one or more times during the step. Assistance is recommended for the user to complete this step. Installment and attachment of the transmission

Steps Of Reassembly

Step Number Part Added and Description Difficulty Picture(s) of the Step Picture(s) of the Step
1 Attachment of the front servo arch to the chassis. We attached the component to the chassis using the two Philips head screws it was originally attached with using a #2 Philips head screwdriver. caption caption N/A
2 Attachment of the front and back suspension systems. There were four screws that attached each suspension system to the chassis totaling in eight screws. A #2 Philips head screwdriver was used to attach them.
  • Attachment of the front servo arch needed to come first because attachment of the suspension system hid the screw holes that attached the component to the chassis.
caption caption N/A
3 Attachment of the steering pivots to the chassis. There were two screws attaching the component, and they were attached using a #2 Philips head screwdriver. caption caption caption
4 Attachment of the motor to the chassis. There were four screws that attached the motor to the chassis and they were screwed into place using our #2 Philips head screwdriver. After the motor was screwed into place the exhaust just slipped onto the motor using a rubber gasket. caption caption caption
5 Attachment of the exhaust to both the chassis and the engine. After the motor was screwed into place the exhaust just slipped onto the motor using a rubber gasket. The exhaust was attached to the chassis using one screw which was attached using our #2 Philips head screwdriver. caption caption caption
6 Placement of the transmission on the chassis and attachment to both the drive shafts and the engine. The driveshaft connected to the transmission slides over the slotted driveshaft connected to the differentials making a secure connection. The transmission connects via meshed gears. The attachment of the transmission to the chassis comes in the next step.
  • please note that realignment of the engine might be necessary to ensure optimal connection to the transmission.
caption caption caption
7 Attachment of both the transmission and the support struts to the chassis. This step takes eight Philips head screws that were attached using our #2 Philips head screwdriver. caption caption N/A
8 Attachment of the other servo arch to the chassis. The component was attached with two Philips head screws which were attached using our #2 Philips head screwdriver. caption caption N/A
9 Attachment of both the servo motors as well as the battery box and the receiver to the chassis. These components were all attached in one step because they are connected to one another by wires that we could not detach. This step required 12 screws that were attached using our #2 Philips head screwdriver. The attachment of these four components to the other components/ subsystems will come in the next step. caption caption caption
10 Attachment of the throttle rod and brake to the throttle servo as well as the attachment of the steering servo to the steering arm. The attachment of the brake to the throttle servo was made using a 1/16 inch Allen key. The attachment of the throttle arm to the throttle servo was made with a pin and nut. The attachment of the steering servo to the steering arm was made with a simple Philips head screw. We used a 1/16 inch Allen key wrench to attach the throttle servo to the brake, a pair of needle-nose pliers to attach the throttle servo to the throttle arm and a #2 Philips head screwdriver to attach the steering servo to the steering arm. caption caption N/A
11 Attachment of the fuel tank to the chassis as well as attaching the fuel lines to both the engine and the exhaust. The fuel tank was attached to the chassis using four Philips head screws that were tightened using a #2 Philips head screwdriver. Before screwing the fuel tank to the chassis we attached the fuel lines to the exhaust and the engine in order to prevent any leakage of fuel. caption caption caption
12 Attachment of the middle plate to the support struts. This attachment was made with eight Philips head screws that were tightened using out #2 Philips head screwdriver. caption
  • we are making an exception to the scale for this components attachment because it was completely out in the open, there were just a large amount of fasteners attaching this piece to the support struts.
caption N/A
13 Attachment of back and front protective plates to both the suspension system and the support struts. The back plate was secured with eight Philips head screws; four attached to the support struts and four to the suspension system. The front plate was secured with ten Philips head screws; four attached to the support struts, two attached the steering pivots, and four to the suspension. All screws were fastened using a #2 Philips head screwdriver. caption caption caption
14 Attachment of front and back bumpers. The bumpers were attached with four Philips head screws in each making a total of eight screws. All screws were attached using a #2 Philips head screwdriver. caption caption N/A
15 Attachment of the wheels to the suspension system. The wheels were attached using four nuts, one for each wheel. A pair of needle nose piers was used to attach them to the suspension system. caption caption N/A
16 Attachment of the plastic body. The body was attached to the body using four cotter pins which were easily put into place by hand. caption caption N/A

Problems Encountered During Reassembly Process

  • During step number 8 we tightened the screw attaching the servo support arch to the chassis too much and subsequently deformed the part. The problem was resolved by

unscrewing the part and trying again, this time making sure not to over-tighten the fastener.

  • (Step 9) As stated in the assembly table we were not able to remove the wires from in between the servos, receiver, and battery box. because of this fact during the installment of

the steering servo, which was placed underneath the chassis, we encountered a hard time trying to fit the servo through the hole in the chassis necessary to get it onto the

bottom of the plate. It took quite a bit of "wiggling around" of the servo to get it through the hole in the chassis, but in the end we were able to get the servo through the


  • (Step 9 and after) After the installation of the electrical components there were wires crossing over a lot of the components making it difficult to access their connections, and thus made it

difficult to install those components. We had to continuously keep moving the wires around to attach the various other components.

  • (Step 13) During installation of the front protective plate we encountered a problem getting all of the screws to fit into their respective holes. The problem was resolved by simply

unscrewing the screws we had in it already and re-positioning the front protective plate before tightening its screws.

Product Explanation

The product was originally in pieces and was assembled about ten years ago by one of the group member's father. When we first received the product it was fully assembled and

upon checking the assembly directions it was concluded that the product was assembled exactly as it said in the directions. All of the appropriate nuts, bolts, and screws were

found securing the right components/subsystems in the right places on the chassis, and everything was in working condition. When the product was first received it also started

and ran with no problems found.

After we disassembled and subsequently reassembled the product we have come to the conclusion that the two processes were similar but not the same. The dis-assembly process

took about 50% less time than the assembly process. It also seemed much easier to take the screws/fasteners off and remove the components than it was to put the

screws/fasteners back on and make sure that the components were in the right place. One of the hardest problems we encountered during the re-assembly process was getting all of

the parts to fit back in their places exactly how they had when we had originally taken the product apart. More often than not we found ourselves attaching a

component/subsystem just to remove/re-position it during the next step just because it didn't fit correctly. During the dis-assembly process the parts didn't have to fit back

together, they just needed to be removed, so once the screws/fasteners came off the step was done and over with.

Design Revisions

Revision #1 Electrical System

It became aware to us, during the initial disassembly, that it was not possible to simply disconnect the two servos and receiver from the power supply box. The removal of the

electrical system proved to be difficult due to the wires and the components being in the way. To gain access to disconnect the wires, the top casing of the power supply must

be removed. To make this process easier, we propose to provide exterior connections to the power supply, through the casing. The revised connection hub will be recessed and

have a gasket around the ports to act as a physical seal when components are plugged into it. This revision results from the need to increase serviceability, and to decrease

the overall difficulty of mass production and assembly.

Revision #2 Electric Motor

Currently the Magic Wheel operates using a two stroke nitro gas motor controlled by a throttle arm attached to a servo motor. This type of setup uses a volatile fuel which is

used for the process of combustion creating loud operation, hazardous emissions, and high fuel costs. Additionally, it warns that it contains a chemical known to cause cancer,

birth defects, and reproductive harm. As an alternative to this nitro gas motor system, we propose that an electrical motor is used in its place.

While the electrical motor does not match the gas powered version in terms of speed, it does have its own advantages. One of these is its superior throttle response time, the

current gas engine requires multiple stages in energy transfer from electrical to mechanical to chemical whereas an electrical motor utilizes a solely electrical energy flow.

By running on a rechargeable battery the car would no longer produce harmful emissions, this touches upon environmental concerns of pollution. Also this goes along with the

societal factors of safety as the handling of the nitro gas is no longer a necessity and its byproducts not existent. Economically the user will no longer have to purchase the

fuel which can run up to 40 dollars per gallon and only need to recharge the battery.

Revision #3 Component Re-positioning

Additionally during reassembly, we noticed that there were unused holes in the chassis which caused confusion of exact component placement. We concluded that the chassis is

part of a modular product family, and may be used in the fabrication of many different RC vehicles. In order to differentiate between models, the chassis could be stamped

with an outline of component locations. This would make it easier for a user to assemble the truck, as it would provide a visual key to help navigate the chassis. However,

the stamping process would be an additional step in the fabrication process and may lead to an increase in the initial cost of the product. This revision is due to the need

to solve difficulties encountered during the assembly and the disassembly of the product, and is aimed to increase serviceability by the user.

Gate 5

This was the final section of the project and in it we created an executive summary outlining the project and why we chose our specific plan of action, we corrected our entire

report and made changes where appropriate, and we gave an oral presentation outlining one of the design revisions that we chose to make for our product.


The following revisions were made to our original wiki report. All revisions were made to try and better our presentation and clarity of our material on this webpage.


Oral Presentation Slides

These are the slides that were presented in class to aid in our discussion of the design revision of the fuel tank.
Figure 5.1 Figure 5.2 Figure 5.3 Figure 5.4 Figure 5.5
caption caption caption caption caption
Slide #1 Slide #2 Slide #3 Slide #4 Slide #5