Automatic Water Rocket Launcher

thingiverse

I built a water rocket launcher prototype but haven't tested it yet. The operating principle works by having the tension spring hold the retaining arms until the desired pressure is reached. For a given distance on the support arm, the tension spring provides enough torque to keep the thrust force exerted by the rocket on the holding arm in place. You'll need a spring with the right constant for the pressure you want your rocket to reach in the water. The flat design should also be able to withstand the weight of the rocket and its water interior. However, I've never tested it yet. For more details on assembly and purchasing parts, check out the images. You'll need to buy a car check valve to put in the middle cylinder where the rocket goes. We want to generate pressure without any leaks.