How to Build a Water Rocket Launcher

https://www.wikihow.it/Costruire-un-Lanciatore-per-Razzi-ad-Acqua

26-08-2024 |
italia |
Acqua |
fai da te |
Tubi in PVC |
Un tappo per tubi in PVC |
Colla e primer per PVC |
Almeno due raccordi a gomito |
Un piano in legno o altra superficie per ancorare il lanciatore al terreno |
Nastro isolante |
Una valvola pneumatica Schrader |
Un trapano con punte di diversi diametri |
Diverse bottiglie da due litri |
Una pompa per biciclette o un compressore d'aria |
Una valvola a pressione opzionale |
Un manometro |

A launcher is any device that helps a rocket take off and, therefore, fly.It can be simple if it appears in the form of a sloped surface, a support, or a device to help steer the rocket.Other launchers may instead be more complex, and be part of the thrust system of the rocket itself.In this article we will see how to build a simple PVC launcher that you can use to launch a rocket made from a bottle full of water, thanks to air pressure.Be careful though, you may end up getting wet using these types of rockets.

Steps

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1
Gather the necessary materials. Go to a hardware store and purchase the materials you will need.You will need some white PVC pipe, the type often used for low-pressure plumbing systems.There are PVC pipes with two different wall thicknesses;choose those of lesser thickness.
- Make sure you purchase tubes of the right diameter for the two main parts of the launcher:the launch tube (which must have a diameter equal to that of the opening of the bottle) and the final cap where the valve will be inserted.
2
Purchase a pneumatic pressure valve. You can get the valve at some auto parts stores, or you can take one from an old car tire or a bicycle inner tube.
- Make sure you use a Shrader valve.Some bicycle inner tubes use Presta valves, which are thinner and do not have a spring inside them.Such valves would not work as well for your launcher.
The diameter of the hole should be approximately 5-6 mm.Thread the valve through the hole until the end of the valve is resting against the inside of the cap, and the threaded part is completely sticking out the other side.
4
Attach the valve to the cap. This is an optional step, but you can attach the valve to the cap if you want.For a simple launcher like the one under consideration, this may not be necessary, since the air pressure should be sufficient to hold the valve in place.That said, there are several ways to glue or secure the valve in such a way as to have a tight fit:
- Drill a hole in a rubber pad and then pass the valve through the hole.The rubber will hold the valve in place, as it will expand slightly when drilling.If you wish, you can also glue or attach the pad to the inside of the tube cap.
- Use caulk or plumber's putty/sealant to close any cracks around the valve;it will prevent air leaks
- Do not use primer or PVC glue on the rubber, it is a different material and may not hold as well.
5
Test the launch tube. Make sure the spout is secure when inserted into the opening of a 2-liter bottle.As the air pressure begins to increase, you will need to be able to push the bottle all the way down the spout, making sure there is enough friction to hold it in place.
- If the bottle's grip isn't tight enough, wrap some electrical tape around the base of the spout.
6
Cut the PVC to the right size. The spout should point upwards, while the cap should be above the water level and also positioned vertically.Now the two corner pieces come into play, with which you will have to connect the two vertical pipes.Also make sure to seal all fittings well, since the entire system will need to be watertight.
- Test the final assembly of all pieces before gluing them.
7
Glue all the pieces together using primer and PVC glue. To connect the various pipes together, follow the steps below:
- Wear gloves.
- Use a towel or rag to remove any dirt from the ends of the pipes.
- Use a pocket knife or file to remove any molding residue or loose plastic parts.
- In a well-ventilated place, open the primer jar and, using the appropriate brush, apply the primer on the external part, and also a little on the internal part, of the end of the pipe to be connected.
- Repeat the process on the tube that you will have to join to the first one.
- Wait a few seconds for the primer to dissolve the plastic slightly and make it 100% clean.The time it takes you to close the primer jar and open the glue jar will probably be enough.
- Apply glue to both ends to be joined.Allow the glue to cover the entire circumference of the tubes, but don't use so much that it drips everywhere.
- Fit the glued pieces together by pushing as hard as you can, and hold them in place for about 15 seconds.
- Remove any excess glue using a towel or rag.
- Place the joined parts on a surface and wait for the glue to dry.It shouldn't take long;read the instructions on the product packaging to find out the recommended waiting time.It may take an entire night for the glue to dry completely.
Try to spill as little water as possible.The water will end up inside the pitcher.It's normal.If you have taped the spout and the bottle is having trouble sliding down the tube, rotate it in the same direction the tape is wrapped as you push it down.
When the pressure has reached a sufficient level, the bottle will launch into the air leaving a trail of water behind it.
When the air pressurizes the bottle and pitcher and is then released, a force is created that pushes the air out of the bottle.This creates an equal and opposite force that pushes the bottle upwards!This is all due to Newton's third law.Increasing the pressure inside the bottle has the effect of increasing the thrust received (Newton's second law).Water is placed inside the bottle to increase its speed, since water is heavier than air.Which is why, by pushing it out when leaving, the bottle will fly further.

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Advice

You can add a nose cone, fins, a parachute, or anything else you can think of to your rocket and see how it works.
To cut PVC pipes you can use a hacksaw or a special pipe saw.
If you use a hacksaw, be sure to remove any chips from the ends using a file or pocket knife.
Bring the bottle you plan to use with you when you go to buy PVC pipes, so you can find the diameter of the pipes needed for it to stay secure.
Launch the rocket in a place free of any obstacles;a large open field is ideal.Avoid buildings, trees and high voltage pylons.
You will have to be careful when connecting the different hoses.If there were vents, you wouldn't be able to pressurize the launcher.
You can file the spout to ensure that it can accommodate bottles of different sizes than the one initially chosen.To do this, use a rasp.
You can purchase an altimeter to measure the height that thrown bottles reach.This way you can carry out various tests to try to understand what the ideal pressure and quantity of water are.
The pressure of the throw will damage the bottle:make sure you have more available.Another trick is to wrap the bottles with insulating tape to make them more resistant.
You can find launchers of this type on the market, or even better types, if you are willing to spend more money.
It would be a good idea to use a pressure gauge on the pump or compressor.The pressure gauge would allow you to see how different pressures affect the launch of your rocket.
Some say that CocaCola bottles work better than Pepsi bottles.

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Warnings

Do not fire the rocket at too steep an angle.It would increase the risk of hitting someone, and the rocket wouldn't fly as far.Furthermore, there is a risk that the rocket will launch backwards.
Do not aim at people, animals, or buildings of any kind.
High pressures increase the risk that the bottle or pitcher will explode, injuring you and those nearby.
Don't get too close to the rocket during pressurization or before launch.
Try to stay at least 1 meter away from the pressurized rocket.
Do not use the launcher in parking lots, you could damage a car and have to pay for the damages.

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Things you will need

PVC pipes
A cap for PVC pipes
Glue and primer for PVC
At least two elbow fittings
A wooden surface or other surface to anchor the launcher to the ground.Use tent stakes if you can't use a plan
Insulating tape
A Schrader pneumatic valve
A drill with bits of different diameters
Waterfall
Several two-liter bottles
A bicycle pump or an air compressor
An optional pressure valve
A pressure gauge

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