How can i create an electric minature car that i can modify to increase speed?

Question

i am planning to create a miniature electric car.. i need the car to be small like those mini cars that you see on science kits.

and i want to be able to modify it to increase speed.

this is a project and its due in 3 weeks... lol so yeh

Answer 1

You can go to a hobby shop where they sell r/c cars and get an elelctroic or manual speed controll for the battery to the engine that wil allow you to change the speeds.

Answer 2

For a small model car... easiest way to increase speed is to increase "cell count" in the battery.

Whatever voltage the motor is rated for and how much load is on the motor... it will survive a short time  on a higher voltage.  Depending on how much more voltage that "short time" may be seconds... or may be hundreds of hours of operation...

so... if you start out with a 6V rated motor on 4 AA batteries...  Go to 6 cells and the car will go faster.  The motor should survive several demonstration runs.

Answer 3

You could start with a something like a remote controlled or slot car. Starting from scratch will take longer.

To make it "faster" do you mean increase the top speed or increase its acceleration?

If you are only interested in acceleration.

Acceleration =Power/weight

Improving power to weight ratio will make it accelerate faster.  Increased power or decreased weight.

Four things will make any vehicle faster.

Reducing wind resistance.

Reducing rolling resistance.

Increasing power.

Optimum gearing

Wind resistance

http://en.wikipedia.org/wiki/Wind_resist...

To decrease wind resistance you can decrease the cars cross-sectional area, improve its shape or both.

To simplify if you arrange your components so that the least area can be seen from the front you will have the best cross-sectional area.

Adding triangular shape twice as long as it is wide to the rear and a semicircular shape to the front of parts on the car will get close to the best shape possible.

Rolling resistance

http://en.wikipedia.org/wiki/Rolling_res...

Reducing weight will make the most improvement in rolling resistance. This needs to be experimented with as removing aerodynamic shapes could have a greater affect.

A lighter battery of the same voltage will increase speed but decrease range.

Slick tyres of higher pressure generally offer improvement also.

More power.

Simple enough just make sure that the percentage increase in power is larger than the percentage increase in weight.

Gearing.

Selecting the right gear ratio to match your motor will give a higher speed. Too low and the car will accelerate well but the motor will peak out short of its optimum power. Too high and the motor will not have the torque required to reach its optimum speed.

Good luck. Some people spend a lifetime on this sort of thing not just three weeks