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The Effect of Spring Resistance on Speed
of a Remote Control Car |
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The purpose of this experiment was to determine the effect of spring resistance on the speed of a remote control car on various racecourses.
I became interested in this idea because for the past two years I have had a strong interest in cars and wondered what resistance of springs made the car go fastest through turns.
The information gained from this experiment could help racers, and people who use 4 wheel drive recreational vehicles to know what springs to buy to go fastest.
My hypothesis was that the springs with the most resistance would create the fastest times on all three courses.
I based my hypothesis on a statement by Michael Seal, the leader of the Technological Institute at Western Washington University, who said that softer springs create loss of cornering power.
The constants in this study were:
- The weight of the car
- The turning distance of controller
- The battery power
- The course size
- Road Surface
The manipulated variable was the resistance of the springs in the back and front of the car.
The responding variable was the speed of the car through the three courses.
To measure the responding variable I used a stopwatch.
| QUANTITY | ITEM DESCRIPTION |
| 1 | XMOD Customizable RC Car |
| 4 | XMOD Springs of different resistance |
| 1 | Metronome that can be set to 40 and 80 bpm |
| 1 | Stopwatch |
| 1 | Pencil and note book |
| 36 | “AAA” Batteries |
1. Set up car for circle testing
a.) install first set of springs
(least resistance)
b.) Install new batteries
c.) Set car at about one third up the centerline
2. Complete circle testingb.) Install new batteries
c.) Set car at about one third up the centerline
a.) Turn steering wheel as far
counter-clockwise as possible
b.) Go to full throttle and start the timer
c.) After 3 laps stop the timer
3. Repeat steps 2a-2c going clockwiseb.) Go to full throttle and start the timer
c.) After 3 laps stop the timer
4. Adjust controller to maintain consistent slow speed
5. Repeat step 2 at slow speed
6. Repeat steps two through five with all resistances of springs
7. Find speed of car
d.) Run car at full throttle
e.) Go for thirty feet
f.) Divide the speed by thirty
7. Adjust controller to maintain consistent slow speede.) Go for thirty feet
f.) Divide the speed by thirty
8. Complete Speed tests
The original purpose of this experiment was to determine the effect of spring resistance on the speed of a remote control car on various racecourses.
The results of the experiment were that the stiffest springs had the fastest time in two of the three categories at full throttle. In the straight speed the stiffest springs lead by about .23 seconds. In the circle to the right the softest springs had a slight edge of .05 seconds over the stiff springs. The circle to right was done fastest by the stiff springs with a time of 13.56, 1 second faster than the soft springs. But overall the softest springs ended up having the fastest time in all three courses.
See my table and graphs
My hypothesis was that the springs with the most resistance would create the fastest times on both courses.
The results indicate that this hypothesis should be rejected.
Because of the results of this experiment, I wonder if different tire shapes or materials would affect the turning ability or speed. I also wonder if different chassis weights would affect the turning ability.
If I were to conduct this project again I would have found a better designed car to be as consistent as I could. I also would have done the experiment in the summer so that I could do it outside. In the winter the cold slows down the mechanics in the chassis. I think a slalom test would be far better than any of the tests I was able to conduct with the car available.
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Introduction Cars have had a big impact on human society. They have revolutionized transportation by enabling people to get from one place to another in a fraction of the time it used to take. Automobiles are the most important form of transportation for millions. Automobiles influence where people work and live. They also impact how peoples’ leisure time is spent. Vehicle suspension based on springs has revolutionized cars by giving a lighter and easier ride with improved safety. Automobiles History The modern automobile was not invented by one person in a single day. The evolution of the automobile reflects a world-wide effort. About 100,000 patents were counted for the modern car. The first theoretical plans for motors were drawn by Leonardo Da Vinci and Sir Isaac Newton. In 1769, the first self-propelled road vehicle was invented by a French mechanic and Engineer, Nicolas Joseph Cugnot. Cugnot used a steam-powered engine to power the three wheeled tractor. It was used by the French military to haul artillery at what was then a fast speed of two and one half miles per hour. The engine and boiler were in front, separated from the rest of the vehicle. The very next year (1770), Cugnot built a steam powered tricycle that carried four passengers. In 1771 Nicolas Cugnot crashed one of his steam powered vehicles into a wall. This made him the very first person to ever have a motor vehicle accident. Henry Ford is perhaps the main reason cars are cheap to buy. He was the leading manufacturer of American automobiles in the early 1900s. Ford established Ford Motor Company in 1903. It was the first company to use assembly lines to lower the costs of production. From 1908-1927 more than half of the cars sold in America were Fords. At the beginning Ford only sold expensive cars like his competitors. In 1908 the Model T arrived and in 1909 they were the only Fords sold. The original price of the Model Ts was too high for customers so he lowered the price with the introduction of the assembly line. How Cars Works Most cars today have a front mounted gasoline burning engine. They also usually have an automatic transmission and front wheel drive. The most common engine is an internal combustion engine. This particular engine works by burning a mixture of gasoline and air inside the closed cylinders. This is a summary of how a Front Wheel Drive car works. When you turn the key it starts the switch. Electricity flows from the battery to the starting motor, cranking the engine. Cranking takes place as the starting motor spins the flywheel. The flywheel turns the crankshaft. Which then starts the pistons moving up and down in the cylinders which activates the fuel pump. When you press the accelerator it opens the throttle, letting the pistons draw the fuel mixture into the cylinders. The engine runs as the battery feeds electricity to the distributor through the coil. The distributor sends the electricity to the right spark plug at the right time. Sparks from the spark plug ignite the fuel. The pistons move in a rapid pumping motion. Pistons move up and down. Connecting rods transfer energy from the power stroke to the crankshaft and flywheel. That transmits energy to the car’s transmission. The steering system turns the front wheels. The steering wheel sits on top of the steering shaft. When the steering wheel turns, the steering shaft twists. The shaft twisting causes the steering gears to push and pull the tie rods. This causes the wheels to turn in the intended direction. Power steering uses an engine-powered hydraulic system to steer the car. The brake system slows down or brings the car to a halt. The majority of cars have disk brakes on their front wheels and drum brakes on their back wheels. Both types are operated by hydraulic pressure. Pressing the brake pedal forces brake fluid from the master cylinder through the brake lines to the brakes. “The pressure of the fluid forces a friction material to rub against the disks or drums on the wheels.” (World Book Encyclopedia. Michael S. Flynn and David J. Andrea. 1998) Safety Problems Each year, about 300,000 people in the world die from car accidents. Forty to 45 thousand of the people who die are Americans, and many of the people are young. More people ages 5-32 years old die from the result of a car crash than any other cause. Drivers are the main factor in vehicle safety because they are responsible for around two thirds of the accidents. This happens because the drivers make bad decisions or break the rules of safe driving. Around forty per cent of all traffic deaths involve at least one drunk driver. How Safety Problems are Being Prevented The car itself has become much safer over the years contributed by advances in the design. Auto makers in the U.S. must meet strict government standards made to prevent accidents. The government makes you have certain lights, reflectors, brakes, tires, windows, windshield wipers, defrosters, and dashboard controls. The governmental standards to protect the people inside the car include seatbelt, airbags, and the bumper system. Economic Problems When cars burn gasoline, they release hydrocarbons, carbon monoxide, and nitrogen oxides into the air, therefore polluting it. Air pollution puts peoples’ health in danger, and damages crops and livestock. Horrible pollution is caused by automobiles in big cities such as Los Angeles and Mexico City. How Economic Problems are being solved In the U.S. the EPA (Environmental Protection Agency) enforces the federal emission standards, limiting the amount of pollution new vehicles may produce. U.S. Automakers reduced the emission of major pollutants by meeting increasingly strict federal standards. Since the 60s, hydrocarbons and carbon monoxide have decreased by 96%. Nitrogen Oxides have been reduced 76%. The reduction is largely due to the catalytic converter. The catalytic converter is placed in the exhaust system and changes carbon dioxide and water vapor. Facts •The word Automobile comes from the Greek word auto which means self, and mobile the French word for moving. •The U.S. has about 25 % of the world’s passenger cars. Americans drive over two and one half miles per year. •About 85% of all American households own a car. About 35% of all American households own two or more cars. •The U.S. uses about 150 billion gallons of fuel per year. Mechanical Springs A spring is a mechanical device that recovers its shape after an outside force changes its shape and is removed. Springs have two basic forms, coil spring, and bending bars. Their two main uses in machinery are to return something to its original position, and to expand after being compressed. The most common form of the spring is the cylindrical coil or the flat spiral. Some examples of this are such things as door springs which contract after being stretched when someone opened the door. Valve springs in a car expand after being compressed . The second main use of springs depends on the amount that the springs change shape when they are subjected to a force. “That is exactly proportional to the strength of the force exerted on the spring- the more it stretches.” The Way Things Work by Michael Dalton. A large number of weighing machines use springs this way. Springs are made of metals, the most common being steel and bronze. Coil springs are made by bending wire into a coil shape. You then anneal and harden the spring. Adding alloys with elements like nickel or chromium helps make the spring withstand heat better. Summary The automobile is an important piece of technology. For many it is the most important piece of technology. It is one of the most important forms of transportation, and it has provided jobs for thousands of people around the globe. Safety depends on every component of a car working perfectly. The suspension system depends on springs. |
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Andrea, David J. and Flynn, Michael S. “Automobiles” World Book Encyclopedia . 1998 “Automobile” World Book Multimedia Encyclopedia Bellis, Mary “The History of The Automobile” January 11, 2005 <http://www.inventors.about.com/library/weekly/aacarsteama.htp El-Messidi. “Automobile Industry” Microsoft Encarta@ Reference Library 2005 Macaulay, David The Way Things Work. Boston: Houghton Mifflin 1988 pp.82-83, 85 Rolfe, Stanley T. “Spring.” World Book Encyclopedia. 1998. Seal, Michael. E-Mail interview, 2001. |
I would like to thank the following people for helping make my project possible:
- My parents for helping me with my project.
- My mom especially for coming to the school gym for every one of those long hours of testing and retesting.
- Mr. Newkirk for correcting my reports every time and having patience with me at after school classes.
- Mrs. Helms for keeping me on track.
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