Water Rocket Forum

I have recently made it to the Science buskers busking round after an audition and will be using my water rocket car made from Lego bricks to demonstrate the power of water rocket and how it works.

You can view some of the pictures for the Science buskers Water Rocket Car here.

The car is dragster like with long body and the attached PET bottle is 500ml. I have pressurized
up to 80psi and it moves off fast. I also add some water and pressurized to 40psi and this time,
i can see the acceleration really fast but when I increased to 50psi, the car flipped instantly.

I believe the car is still not quite stable yet and I'm wondering what I could do to make the car more
stable so that i can test higher pressure with more water.

If its flipping over widen the front and rear axle a little, you will know when you have it wide enough as the car will spin rather than flip over. At that stage add a a rear wing to provide downforce over the rear wheels, this will stop the spinning.

Take a look at our website, there is lots of information about water rocket cars and the things we have tried to get a stable water rocket car.

http://wrocket.hampson.net.au

Good luck at the competition

-todd-

thomashoi wrote:I have recently made it to the Science buskers busking round after an audition and will be using my water rocket car made from Lego bricks to demonstrate the power of water rocket and how it works.

You can view some of the pictures for the Science buskers Water Rocket Car here.

The car is dragster like with long body and the attached PET bottle is 500ml. I have pressurized
up to 80psi and it moves off fast. I also add some water and pressurized to 40psi and this time,
i can see the acceleration really fast but when I increased to 50psi, the car flipped instantly.

I believe the car is still not quite stable yet and I'm wondering what I could do to make the car more
stable so that i can test higher pressure with more water.

You should (if allowed) glue your legos together with some CA glue. The joints in legos add a lot of flex to the structure and this makes the entire structure weak. Even if your rocket car is properly shaped, the legos will be much less rigid and this will lead to potential failure.