UEET 101
The Reverse Engineering of a Remote Controlled Car
Group 5
Josh Fox, Group Leader, Webmaster (EE)
Scott Eckhardt (ME)
Ryan Erdell (EE)
Tom Ewert (IE)
Wade Flemons (EE)
Mark Flynn (ME)
Peter Gaines (ME)
Objective: The objective
of this team-based design project is to select a household project and perform
a dissection as to identify electrical, mechanical, and industrial engineering
aspects of our product, which is an radio controlled
car. The outcome of this project is to
be able to show other people how engineering is used in a normal, everyday
household project.
Chapter 1: Introduction: Remote Controlled cars came
from humble beginnings in the mid 60’s at which time they were all mostly gas
powered cars. Cars were normally 1/8th
scale gas models. The first all electric
R.C. Car came in 1976 when Tamiya shot its opening salvo with the introduction
of the 1/12th scale Porsche 934 turbo followed by the first all terrain car in
1979. Although there is somewhat of a long
history for radio controlled cars, Jada Toys was not created until 1999 when
Jack and May Li opened their headquarters in
Chapter 2: The
Mechanical Engineering Aspect:
Starting in the front of the car are the wheels, which are connected to spindles. Attached to the spindles are two very small shocks. The shocks have 2mm of travel. The shocks would have to be designed to be effective, yet light enough to go on such a small r.c. car (remote-controlled car). Different angles of the shocks may be considered to give the car the smoothest ride. Also connected to the spindle is a lever used to steer the car. Although there are many ways to steer a car, a mechanical engineer would have to design and develop the most optimum way to steer this car. The lever connects in the middle to a small electronic motor. In the back of the car is another set of wheels, which are connected to the axles. Connecting the axles to the electronic engine is a set of small gears acting as a transmission. The gears would have to be designed to be able to give the car enough torque without taking away too much of the speed. If there were too small of a gear it would take a lot of labor from the electronic engine to spin the wheels. On the other side, if there were to large of gears it would be easy for the engine to turn the wheels, but there would not be very much top speed. The gears of this car are quite simple and lightweight which is perfect for a small toy car. The gears consist of a perfect sacrifice between durability and less costly material.
Chapter 3: The
Electrical Engineering Aspect
There are several electrical engineering aspects considered and developed in the design of a r.c. car. The car takes the 1.2 V from the 6 AA batteries and transforms it into motion. Starting at the battery storage area running to the outside of the car is two wires. The wires are connected to an on/off switch. Going to the rear of the chassis from the battery pack is two wires running to the electric engine. An electrical engineer would have to calculate how much power the car would need to be released from the engine. After doing that he or she would have to either design an engine for the job. This engine is what gives the car its positive or negative velocity. At the front of the car is another small motor. This motor controls which way the steering shaft turns thus changing the direction the car steers. An electrical engineer would have to be sure that the designed engine would have enough power to turn the wheels. In middle of the car above the battery pack is the circuit board. The circuit board acts as the brain of the car. Inside here you can find many different parts including capacitors, diodes, resistors, and the antenna. The antenna plays a vital role in the brains of the car. It takes the user input from the remote and turns it into action within the car. This area of the car would be where an electrical engineer would spend most of his time. He or she would have to design the circuit board, consider needed electronic pieces, and design the receiver. Along with the receiver there needs to be a transmitter in the remote. An engineer would have to take several considerations with this piece. First would be the battery. This remote uses a 9V battery to power the component. Also the controls would need to be designed. From the remote you control the direction the car goes whether it be forward to back, or left to right. Also connected to the circuit board are more of the capacitors, diodes, resistors, and the transmitter. An electrical engineer would have to design the transmitter/receiver while bearing in mind that there are regulations set by the Federal Aviation Administration on radio frequencies being transmitted. This car runs on 27 MHz, which seems to give an ample range of 235 feet. All electronics on this car worked exceptionally. The range of the car from the remote doubled our expectations.
Chapter 4: The
Industrial Engineering Aspect
The most overlooked aspect of this project seems to be the packaging. An industrial engineer would have to plan a packaging that would both fit the car well, while cutting down any waste and ensure that the packages would all fit into large boxes well for shipping and distribution. Along with the packaging for the car another issue that an industrial engineer would have to consider is how the car would be secured in the packing to keep it from breaking.
Chapter 5: Conclusion
The design of the radio-controlled car is not perfect. Most R.C. Cars lack the durability and battery life that most people would enjoy. Manufacturers use as much plastic as possible in an effort to reduce the cost of materials and to make production simpler. The cars are normally fitted with universal electric motors and components to reduce cost between the different models of cars. The remote controller is generally the same for all cars to reduce cost. One issue noticed was with the steering control. The car never wanted to steer straight. Though the current steering mechanism is more cost efficient, a renovated steering control would be preferred for better operations. One thing that could be done to cut costs would be to eliminate the front shocks of the car. They only supply about three millimeters of suspension travel and do not operate very well. Even without the shocks the car would hold up from road conditions. Unpacking the car became a tedious chore. To remove the car we needed two different screwdrivers. It took approximately fifteen minutes just to remove the car from the packaging. Recommendations may be to either include a screwdriver that could remove a single type of screw, or to use straps that could easily be removed with any household pair of scissors. Also, when placing the batteries into the car and into the remote, two different screwdrivers were need; in our eyes this was unacceptable. The perfect answer would be to use one type of screw for the packaging and the batteries and to supply an inexpensive screwdriver.
References:
http://en.wikipedia.org/wiki/Jada_Toys http://www.jadatoys.com/info.php?sub=about http://www.rcracer.dabsol.co.uk/RC_Car_History.htm http://www.kyosho.co.jp/web/about/rccar_history01-e.html
Miscellaneous comments:
Since this was a group project the team expected participation from all members of the party. Meeting times remained flexible, but we did not receive participation at any of the meetings from two of the team members. Ryan Erdell and Wade Flemons do not deserve the same grade as the others who participated as much as their schedules would allow.