Make your own water bottle rocket launcher! - Part 2 of 3

Summary

This instructional video script outlines the process of building a water bottle rocket launcher. It details each step, from preparing the PVC components with primer and cement, creating a bulge for the water bottle seal, to assembling the launch rail and constructing the trigger mechanism with wire ties and duct tape. The script also covers the creation of a spring mechanism using a cut two-liter bottle and a band clamp, ensuring the rocket is held securely until launch. Finally, it describes the firing mechanism assembly, using nylon string and a coupling, to release the rocket for flight.

Takeaways

• 🔧 Start by threading the valve stem through a half-inch hole in the end cap using pliers and a rag to avoid marring.
• 🚀 Ensure the valve is well seated within the end cap to hold the pressure needed for launching the rocket.
• 🛠️ Assemble the launcher base using PVC cement, primer, and end caps, ensuring proper ventilation and cleanliness.
• 🔗 Attach the end caps and tees to create the main launch rail and support structure, taking care to avoid glue blockages.
• 🔥 Use a heat source to create a bulge in the long piece of PVC for a water bottle seal, being cautious in a well-ventilated area.
• 📏 Measure and mark the PVC at 10 inches to form the launch rail, ensuring it's straight and properly aligned.
• 🔨 Attach the tees and other PVC components to build the complete launch platform, maintaining a vertical orientation for stability.
• 🔗 Create a trigger mechanism using wire ties, duct tape, and zip ties to secure the bottle and control the launch.
• ⚙️ Use a band clamp and a cut two-liter bottle as a spring to hold the rocket in place until launch.
• 🎯 Construct a firing mechanism with a nylon string and a drilled coupling to pull the trigger and release the rocket.

Q & A

What is the first step in assembling the valve sim through the half-inch hole?

The first step is to insert the valve sim from the inside of the end cap to the outside, then pull it through using pliers and a rag to avoid marring.

Why is it important to use a rag when pulling the valve sim through?

Using a rag prevents marring or scratching the valve sim while pulling it through the hole, ensuring a smooth and damage-free process.

How do you ensure the valve sim is properly seated within the end cap?

After pulling the valve sim through, you should see a little rim pop out. Continue pulling until it is well seated within the end cap to hold the pressure needed for launching the rocket.

What is the purpose of using PVC cement and primer when building the launcher?

PVC cement and primer are used to bond the PVC pipes and fittings together, creating a secure and airtight connection that is essential for the proper functioning of the rocket launcher.

Why is it recommended to apply PVC primer and cement in a well-ventilated area or outside?

PVC primer has a strong odor and can create a mess, so applying it in a well-ventilated area or outside prevents inhalation of fumes and keeps the workspace clean.

How do you create a slight bulge in the long piece of PVC for the water bottle seal?

You heat the entire circumference of the PVC at the 10-inch mark using a candle or heat gun until it becomes warm and pliable, then apply pressure to create a slight bulge while it cools.

What is the purpose of the bulge in the PVC pipe?

The bulge in the PVC pipe is where the water bottle seals against when launching, ensuring an airtight seal for the pressure to build up and launch the rocket.

How do you attach the trigger mechanism to the launch rail?

You use wire ties to attach a piece of duct tape with six medium zip ties spaced evenly across it to the flange of the bottle when it's on the launch rail.

What is the function of the spring in the water bottle rocket launcher?

The spring acts as a release mechanism, holding the rocket onto the launch rail until the firing mechanism is pulled, at which point it releases the rocket to launch.

How do you create the firing mechanism for the rocket launcher?

You drill a small hole in a 1.25-inch coupling, thread nylon string through it, and tie it off. This assembly is placed over the launch rail and zip ties, and the string is threaded down through two holes to create the pull mechanism for launching.

What is the final step to fire the rocket using the launcher?

The final step is to put the bottle over the launch rail, pull down on the firing mechanism to seat the rocket, and pressurize it. Then, pull the string to release the rocket.