10

Build and Launch Foam Rockets

NICK MADSEN / YOUTH SERVICES SPECIALIST AND MAINTENANCE MANAGER

Community Library Network: Kootenai and Shoshone Counties Project originally developed by Randy Zepeda

Type of Library Best Suited for: Any

Cost Estimate: $45–$75

Makerspace Necessary? No

PROJECT DESCRIPTION

This project details how participants can build a foam rocket and assemble a rocket launcher to launch their own rockets more than 100 feet.

OVERVIEW

The rocket launcher for this project is designed with PVC pipe and a sprinkler valve. Air is loaded into the launcher with a bike pump or air compressor, and when the air is released, a small rocket can be launched over 100 feet through the air. Insulation tubing, cardstock, and duct tape are used to create the rocket. The sprinkler valve can be manually released to launch the rocket. Alternately, a push-button switch can be wired to the sprinkler valve to launch the rocket.

Please note: This launcher does not include any inherently dangerous components, but the rocket is launched by releasing pressurized air. Be aware of the pressure ratings of each of your components, and practice safety and common sense while using the rocket launcher. For additional safety, wrap the exterior of your rocket launcher in duct tape.

MATERIALS LIST

Rocket Materials

Rocket Launcher Materials

FIGURE 10.1

Materials

NECESSARY EQUIPMENT

Bike air pump or air compressor

STEP-BY-STEP INSTRUCTIONS

1. Build the Rocket Launcher

Decide whether your participants will assemble the launcher at the event or if it will be assembled by a staff member beforehand. Allow 30–45 minutes for assembly. The bulk of your launcher will be 2-inch PVC pipe, and will measure about two feet across when completed. There will be a measurement assembly on one end, a launcher assembly in the middle, and a cap on the other end. Zip ties and pieces of PVC pipe will be used to stabilize the launcher. Keeping safety in mind, use thread seal tape and PVC pipe cement to join your pieces together.

Measurement/Fill Assembly

Put the ¾-inch blowout plug into the 2 × ¾-inch brush with female thread and insert that into one side of the 2 × 2 × ½-inch female threaded tee. Put the ½-inch MIP × ¼-inch FIP brass pipe bushing onto the ¼-inch NPT bottom mount gauge and attach that to the top of the 2 × 2 × ½-inch female threaded tee. This assembly will let you fill the launcher with air and will also let you measure the pounds per square inch inside of the launcher. Attach a one-foot length of 2-inch PVC pipe to the opposite side of the female threaded tee.

Sprinkler Launcher Assembly

Put the 1 × 3-inch male threaded joint onto the top of the 2 × 2 × 1-inch female threaded tee. Put the 1-inch inline sprinkler valve onto the male threaded joint, and place the 1 × ¾-inch male threaded adaptor on the other side of the inline sprinkler valve. Take a one-foot length of ¾-inch PVC pipe, and attach that to the top of the ¾-inch male threaded adaptor. Place one side of this completed assembly onto the other side of the one-foot length of 2-inch PVC pipe from the measurement/fill assembly. Finally, place a second one-foot length of 2-inch PVC pipe onto the opposite side of the 2 × 2 × 1-inch female threaded tee. Close the other side of this second piece of PVC pipe with the 2-inch cap.

Stabilizers

Cut two 2-foot lengths of ¾-inch PVC pipe. When completed, these lengths will be stabilizers for your rocket launcher. Each stabilizer should be perpendicular to the finished rocket launcher, one positioned near the measurement/fill assembly, and the other close to the 2-inch cap. For each of the two stabilizers, create two holes in the PVC pipe. The holes should be positioned near the center of the PVC pipe around three inches apart from one another. Thread a zip tie down through one hole and back up the other. Join the zip tie together over the top of one of the ends of the finished rocket launcher. The following picture shows the completed “H” shape that is created.

FIGURE 10.2

Rocket launcher stabilizers

2. Build the Rockets

The majority of the participants’ time will be spent building, testing, and redesigning their rockets. The simplest form of rocket is built with a one-foot length of ¾-inch or 1-inch insulation tubing, a rocket nose cap made from cardstock or thin cardboard, and fins made from cardstock or thin cardboard. Individual rockets can be wrapped in duct tape to ensure they are airtight. After launching their rockets, participants should brainstorm how they could improve their design (i.e., changing fin shape, trimming weight, rebuilding the nose shape), and then spend time rebuilding their rockets for another round of launches. Each round of building, redesign, and launching can take between 30 and 45 minutes.

3. Launch the Rockets

The sprinkler valve assembly will have an open and closed setting. Make sure the valve is in the closed setting while filling the launcher with air, and then release the air by switching the valve to the open setting. As mentioned previously, use common sense and safety while launching these rockets. Determine the piece of your assembly that can handle the lowest amount of pressure and do not exceed that amount of pressure.

LEARNING OUTCOMES

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