Rubber Band Power? Optimal Length?

[Jragon]

Hi There!

 

Me and a few friends are making a rubber band powered car. We've made the designs and know how it is going to work.. I think it's rather interesting. I've got the job or research and CAD models.

 

We're going for speed, but it must be able to travel 10 meters.

 

Our design is rather simple. There is a tube with the rubber bands running through it, which is connected one end to a disk which will spin, creating the drive. On the other end there is a keyring which all the bands are attached to, for spinning. Once the talk is created it will go through 2 bevel gears to drive the back axle pushing the car forward.

 

3 things I need to know:

 

1. What legnth/width/diameter rubber band should I go with to make it go the fastest

2. What sort of weal should I use

3. How would I make it be able to free wheel

 

All help would be much appreciated!

 

Thanks very much!

 

Jragon

[Jragon]

Here are some VERY basic models, just to show you what it might look like.

 

 

 

[Turtle]

Hi There!

 

Me and a few friends are making a rubber band powered car. We've made the designs and know how it is going to work.. I think it's rather interesting. I've got the job or research and CAD models....

3 things I need to know:

 

1. What legnth/width/diameter rubber band should I go with to make it go the fastest

2. What sort of weal should I use

3. How would I make it be able to free wheel

 

All help would be much appreciated!

 

Thanks very much!

 

Jragon

 

thanks 4 choosing hypography J. interesting design! :thumbs_up i don't recall ever seeing it. the game is affot afoot!

 

1) i would just experiment with different bands and chart the results. :smart: i don't know enough about the physics of elasticity to offer any theoretical conjecture.

 

2) not sure if you are asking about the type of material or the size. however, the larger the diameter of wheel, the longer the car will be under power for a given number of twists of the band. given a specific gear ratio you can calculate the approximate number of wheel rotations given a specific number of twists. experiment, experiment, experiment. :steering: :lol:

 

3) a centrifugal clutch should take care of free wheeling.

 

good luck & please keep us posted throughout the project.

[Jragon]

Thanks!

 

I would have the drawings, but they're at my school.

 

I do have to say, it is an interesting design, and I hope it works.

 

Sadly for the challenge, I'm not allowed to use Mechanics. So that rules out Gears(Though the Bevel gear should be fine.)

 

Thanks for your help!

 

http://scienceforums.com/topic/20159-distance-rubber-band-car-project/

 

I found that post, but I don't know exactly how I'd use it to find out how fast to get it..

 

Also, they're will be more than one rubber band in the celender(No idea how to spell :S).

 

Thanks Again,

 

Jragon

[Turtle]

Thanks!

 

...Sadly for the challenge, I'm not allowed to use Mechanics. So that rules out Gears(Though the Bevel gear should be fine.)

 

Thanks for your help!

...

Jragon

 

roger. i don't understand what you mean by "not allowed to use Mechanics". can you clarify this? a gear is a gear, whether bevel or not.

 

definition of gear

a. A toothed machine part, such as a wheel or cylinder, that meshes with another toothed part to transmit motion or to change speed or direction