Designing a Mouse Trap Car: Wheels and Axle

In summary, the key to making a successful mouse trap car powered solely by the potential energy of a standard mouse trap is to come up with a way to increase the potential energy of the spring. One way to do this is to attach a lever to the spring. By doing this, the car can travel a much greater distance than if the car only relied on the string to pull it.
  • #1
mattfelner
6
0
Hi all, new guy from CT. We were just assigned a project in physics to build and design a mouse trap car powered solely by the potential energy of a standars mouse trap. The main focus is distance, and so that is what I am aiming for. I have my basic design laid out, as I will attach two eyeholes (the bronze kind that screw into the wood) to the front and back of the trap, and I will slide an axle through them connected to the wheels. It will be powered by a string that is attached to a hook on the axle, so when the mouse trap springs forward it puts tension on the string, thus moving the car forward. Here is my question. I am trying to figure out what to use as an axle/wheel. Considering I am going for distance, would the optimal setup be a small diameter axle, with a large diameter wheel? Or the other way around. Speed/acceleration really isn't an issue, however I need to consider that the mouse trap has a limited amount of force, so i need to have drivetrain components that have relatively low inertia. Sorry about the long post, but what setup should I use to roll the trap car a long way?

Also, I am good with design/building, but I really have a limited amount of tools and such.

For the wheels, I was considering stryrofoam plates or CD's wrappe with a rubber band. Axle I really have no idea. Thanks so much.
 
Physics news on Phys.org
  • #2
Back when I did this project back when I was a freshman in HS so very long ago I believe we employed CD's for the back wheels with rubber bands around them. I can't say much besides it went so slowly that the teacher accidentally called the contest over before the car even went 10 feet. Over the course of 2 or 3 minutes it went a few hundred more feet. You're on the right track having an incredibly high gear ratio but make sure that axle's greased or it won't move.

Your string attached to the axle (assumably wound around it at first) is about the best you can get with a mousetrap car. What formula are you being scored by? Like the formula when I did the project was mass of car * distance traveled / length^2 or something to that effect. Just remember that every piece of weight counts. I remember cutting holes in my cd wheels and wooden frame everywhere that wasn't absolutely necessary to get rid of all of the dead weight. Ah memories. Good luck!
 
  • #3
Thanks a lot Vsage.

I'll have to check on the formula, so I'll report back.
Do you think their is a much better way to mount the axles so that they have much less spinning resistance? Also, I was thinking that styrofoam plates considering they are lighter than CD's, that they would offer an even greater gear ratio, with less weight, wouldn't that translate into more distance/less effort? Or does the momentum of the CD's help at all?
 
  • #4
mattfelner said:Hi all, new guy from CT. We were just assigned a project in physics to build and design a mouse trap car powered solely by the potential energy of a standars mouse trap.
The key in what you just said is:
powered soley by the potential energy of a standard mouse trap.
You're dealing with potential energy here. So, you must ask yourself, "When my arm is in it's firing (spring loaded) position that is attached to the string that is attacted to the axel which will rotate my tires, where is all of the potential energy stored?"

Try and figure this out. When you have, you will find an excellent way to increase that PE and make a great mousetrap car.

Paden Roder
 
  • #5
I suppose the potential energy is stored in the spring itself. How would this benefit the car?

Thanks, Matt
 
  • #6
mattfelnersaid: I suppose the potential energy is stored in the spring itself. How would this benefit the car?
Think about it a little harder. How are you going to get your car's rear wheels to move? The string will pull it, correct? Well, what's pulling the string? How far is it pulling it? Is there any way to increase that?

Maybe this will shed light.

Your thoughts...?
Paden Roder
 
  • #7
I see..what I did was attach a 12" lever onto the spring itself, allowing for a greater distance of travel, and more revolutions. I tested the car and got something like 16m, which far surpasses the requirements. Thanks to all!
 
  • #8
Good job.
Way to think it through yourself. After all, it is a learning process.

Paden Roder
 

1. How do I choose the right wheels and axle for my mouse trap car?

The key factors to consider when choosing wheels and an axle for a mouse trap car are size, weight, and material. The wheels should be large enough to cover a good distance with each rotation, but not too large that they add unnecessary weight. The axle should be strong enough to support the weight of the car and any additional load, but not too heavy that it slows down the car. It is also important to consider the material of the wheels and axle, as a smooth surface will reduce friction and improve the car's speed.

2. Should I use one or two axles for my mouse trap car?

This depends on the design of your car and the purpose of the competition. If you are aiming for speed, a single axle may be more efficient as it reduces the weight and friction. However, if you are designing a car for a longer distance or to carry a heavier load, two axles may provide more stability and balance.

3. Can I use any type of wheels for my mouse trap car?

No, it is important to choose the right type of wheels for your mouse trap car. Rubber or plastic wheels with a smooth surface are ideal as they have low friction and can grip the surface well. Avoid using wheels with tread or grooves as they can create more friction and slow down the car.

4. How do I attach the wheels and axle to my mouse trap car?

The wheels and axle can be attached using various methods such as hot glue, tape, or screws. It is important to secure the wheels and axle in place to prevent any movement or wobbling. It is also a good idea to test the attachment before the final race to ensure everything is secure and working properly.

5. What is the best way to reduce friction between the wheels and axle?

To reduce friction, you can use lubricants such as oil or graphite powder on the axle before attaching the wheels. This will create a smooth surface and help the wheels rotate with minimal resistance. You can also sand down any rough edges on the axle and wheels to further reduce friction.

Similar threads

Advice needed for producing a water powered car model project
    • Introductory Physics Homework Help
Replies
4
Views
891
Question about car braking and tire friction
    • Introductory Physics Homework Help
Replies
19
Views
1K
Determine if a car can pop a wheelie?
    • Introductory Physics Homework Help
Replies
15
Views
2K
Potential energy in a mouse trap
    • Introductory Physics Homework Help
Replies
7
Views
4K
What is the best beam design for my aluminum tandem axle trailer?
    • Mechanical Engineering
Replies
33
Views
3K
Opposing force of the axle when a torque is applied to a wheel?
    • Mechanics
Replies
4
Views
1K
General Discussion: Mouse Trap Car Pulling Mass
    • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
Auto/Motor Design to 3D print RC car - Steering
    • DIY Projects
Replies
8
Views
233
How can I build the most efficient mouse trap car to travel over 175 feet?
    • Introductory Physics Homework Help
Replies
1
Views
2K
Building a Mousetrap Car for High School Physics Class
    • Mechanics
Replies
3
Views
1K

Hot Threads

Recent Insights

Back
Top