Jump to content
Science Forums

Rubber Band car


Recommended Posts

i appologize, as I am new to these forums, I have not expressed myself clearly

This project is a CONTEST between students in our physics class, the distance required to get an A is 4 meters, however the winning car in the class will be one that travels the farthest. There are certain rewards for the winner, and that is why I want to maximalize the distance beyond the 4 required meters

Link to comment
Share on other sites

My thoughts.

 

Make a perfect system that collects the rubber band as it unravels from your prepullsion axel, as to avoid dragging it on the ground and accidently running it over.

 

Make sure when the band is done powering the car it releases cleanly from the axle.

 

Modify the diameter of the part of the axle the rubber band is pulling on.

 

But, at the same time avoid having the cars tires burn out, slip.. If you can put rubber bands around the tires as to make good traction. Then set-up the car so it accelerates as fast as possible (using the axel diameter modification) but will not burn out. This will give you the best fight over friction.

 

Then you want to use some very smooth axel bearings of sorts. You can use straws, or washers. But make it so all the wheels spin almost friction free.

 

Make the car as light as possible and put all the weight where the prepulsion tires reside.

 

Warm up the elastic bands before winding them up. Keep them in hot water. Then cool them before race time. This will give you maximum stretch, and maximum power.

 

those are my quick thoughts.

Link to comment
Share on other sites

Are there any limits on the rubber bands you're to use? Thickness, width, etc.?

 

Another thing, like Arkain said, make sure your tires don't slip. This will happen very easily, so if you can, wrap your wheels in elastic as well, to give it more grip and traction.

 

Your drive-train should have the actual axle on which the band unwinds. This should be connected via a step-up gearbox to your driving axle. This configuration won't only give you more speed, but will put more stress on the driving axle, so that the elastic don't unwind at once. It will spread the elastic's propulsion evenly, so that you don't suffer wheel-slip, and get more bang for your buck.

 

4 meters are for sissies - a wound-up rubber band has a lot of energy, able to push tiny little cars a looong way - as long as you don't make the classic mistakes of wheelslip and direct drive...

 

My 2 cent's worth of pit-talk...

Link to comment
Share on other sites

My 1 cent... :shrug:

 

The highest power range is at takeoff, so to avoid wheel slippage and store some of the initial energy, use heavy (or weighted) wheels on the drive axle. This serves as a traction aid (without adding extra weight on the axle bearings) and acts as a flywheel (releasing energy after the rubbber band is released).

 

Release is simple, use a short headless pin on the axle to hook it on and wind it adjacent to the pin so it doesn't hang as it unwinds. Anchor the rubber band above the axle so it pulls upward and will clear the ground when it slips off the pin.

 

Boerseun's suggestion to use rubber bands around the drive wheels for "stickier" traction is an excellent idea, but I'd enquire about the legality of gearing, rubber band size and max vehicle size. With no limits you could build one to carry the teacher well beyond 4 meters, although it might be kinda hard to wind up... ;)

 

moo

Link to comment
Share on other sites

haha, thats awesome.

 

You could make a hell of a car from the sounds of it.

 

Its not 'really' about the distance. Your teachers want you to learn what you can achieve when you put your mind to it.

 

Not many people invent, however its a great thing to learn about while getting an education!

 

Yeehaw gramma.

Link to comment
Share on other sites

  • 3 weeks later...

Thank You everyone!

I had two models by the end of this project. My gear powered car went 20.4 meters and I also built, and cutomized the coffee can car design, my mod. went 33.8 meters. For the mod, I added a wheel to the back on an extention rather than using a traditional pensil, therefore stabilizing it when doing over bumps. This car was excelent at keeping to a straight path and thus I was the class winner, the closest in all 3 honors physics classes was 15.4 meters. As you have stated; however, it is not about the distance, I am most proud on making my gearbox design to work.

Thanks again Everyone :hihi:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...