HELP Trying to Make a Spring Car No Mouse Traps

[panthrt]

I am a senior in High School, I have been given a 3" X 1/2" compression spring that must power a car. This is not a mouse trap powered car, (that was last year). I need help trying to determine high to harness the extreme energy stored in this heavy spring and somehow get a car to travel the farthest. In the mouse trap car it was very easy I simply used a rod long enough to slowly release the energy over a long time period. With this spring I would need a 2X4 attached to wheels. I have tried to attach a small fish line to the spring and then around the axle, but there is so much pressure when the spring is compressed that it does not wrap around the axle. I have tried wire, wax string rubber coated string, I just think that variation will not work, I need some other input. Thank you Nate!

 

[jambaugh]

Try using a lever on the spring to reduce the force then use string on end of lever wrapped around an axle.

There are four basic machines I can think of which can trade off force vs. distance of travel.
The lever
The pulley
The inclined plane or wedge
and systems of pistons pneumatic or hydrolic.

I would guess a piston system is too complex for your application.
I would think a wedge system would have too much friction for your application. These are better for increasing forces.
This leaves levers and pulleys and I think you'll find some combination is best.

I would also suggest you try thinking of the problem in reverse... how to compress or stretch that spring by rolling your car. This may help you visualize different possible configurations.

 

[astrokreng]

Hello Nate,

Thank you for reaching out for help with your spring car project. I am happy to provide some input and suggestions.

Firstly, it is important to understand the properties of the spring you have been given. This includes the material it is made of, its spring constant, and its maximum compression length. This information will help you determine the amount of energy that can be stored in the spring and how much force it can exert.

Next, you can start thinking about different ways to harness the energy stored in the spring. One option could be to use a lever system, similar to what you did with the mouse trap car. You could attach the spring to one end of the lever and the other end to the car's wheels. As the spring is released, it will push against the lever and propel the car forward.

Another option could be to use a gear system. You could attach the spring to a gear and have it turn as the spring unwinds, which would then turn another gear attached to the wheels of the car. This would allow for a more controlled release of the spring's energy.

You could also consider using a pulley system. By attaching the spring to a pulley and having a rope or string wrapped around it, you can create a system where the spring's energy is transferred to the car's wheels as the rope unwinds from the pulley.

Overall, the key is to find a way to slowly release the energy stored in the spring over a longer period of time, rather than all at once. This will allow for a smoother and more controlled movement of the car.

I hope these suggestions are helpful and I wish you the best of luck with your project. Remember to always approach scientific challenges with an open mind and a willingness to experiment and try new things. Happy engineering!