Hobbies And Interests
Things You'll Need
Instructions
Build the Rocket
Empty the bottles and rinse them with water.
Cut and peel the labels off two of the bottles. Do not scratch the bottle as this will weaken the plastic.
Wrap the strapping tape twice around the center of the bottle to reinforce the plastic so it can hold pressure. Make two more rows of doubled strapping tape a couple of inches above and below the middle of the bottle.
Mark where to put fins on your rocket. To make three fins, divide the diameter of the bottle by three. Mark the bottle at each spot with the permanent marker. Be sure to draw completely straight guidelines for the fins.
Create fins for your rocket out of the plastic folder. A basic fin is a triangle made of plastic folded over once. Draw a triangle with the longest side as the folded side of the folder and a right angle on the other side. On the second longest side, cut an extra flap of 1/2 inch to 1 inch of plastic to attach the fin to the bottle.
Make three identical fins out of the plastic folder. Fold the extra flaps out to attach to the bottle. If you want, glue the two sides of each fin together for extra security.
Place the fins along the three equidistant guidelines you traced earlier on the bottle, but make sure the fins don't extend past the end of the bottle. Place them close to the back of the rocket, which is the top or mouth of the bottle. Attach them firmly to the bottle with strapping tape.
Cut off the bottom of the second 2-liter bottle. Cut around the circle about half-way or two-thirds of the way from the mouth of the bottle.
Reverse the bottom of the second bottle and tape it back to the top. Now the bottom of this bottle will be inside the top half where you cut it. The top half will become the nose of your rocket.
Tape the second bottle to the first bottle, lining up the two bottoms and attaching them firmly with strapping tape.
Build the Launcher
Cut the 10-foot pipe into five sections of 2 inches, 18 inches, 22 inches, 30 inches and 48 inches.
Hold one of the PVC end caps with a pair of pliers and drill a 1/2 inch hole in the center of it.
Put the tire valve in the hole in the end cap and pull it through with the pliers until it forms a seal.
Lay out the PVC pipes in order. The end cap without the tire valve will attach to the 18-inch pipe, which attaches to the slip "T" connector. On the middle of the T, place the 2-inch pipe, which attaches to the end cap that holds the tire valve. Opposite the 18-inch piece, the "T" attaches to the 30-inch pipe, which leads to the two 1/2-inch adapters and then the 48-inch pipe. The threaded adapters are optional but allow you to create a tall overhead launcher that can be taken apart for easier transport. The height of the launcher makes it safer and prevents people from getting struck when the rocket launches.
Sand and prime all the pipe connections and glue them together. Always use PVC cement outside to avoid breathing the fumes.
Create a seal for the mouth of the bottle. Place the bottle over the end of the launcher, leaving a few inches between the bottom of the bottle and the end of the launcher. Mark where the mouth of the bottle is on the launcher. Cut a shallow groove around the PVC pipe at this point with the hack saw. Wrap several rounds of Teflon tape around this groove.
Create a trigger so the bottle will launch only when you are ready. Cut the eight plastic zip ties so they are each 5 inches long. Line them up along the ruler so the heads are even and the ties run parallel. Firmly duct tape the ties in this arrangement on both sides of the ties.
Drill a hole in the 1 1/2 inch PVC pipe. The hole should be near one end but not so near it that the pipe becomes flimsy. Run the twine through this hole from the inside of the pipe to the outside and tie a knot on the outside of the pipe to hold the twine in place.
Assemble the trigger mechanism. Place the duct-taped zip ties on the 48-inch pipe so the heads of the zip ties sit just above the bump on the pipe, where the mouth of the bottle will sit. The heads of the zip ties will hold the bottle on the pipe. Firmly attach them onto the pipe with the hose clamp.
Slip the 1 1/2-inch pipe with the twine over the end of the 48-inch pipe until it slides over the zip ties. When you place the bottle on the launcher, the heads of the zip ties will hook over the lip of the bottle, and the larger pipe will hold them in place until you pull it down by pulling on the twine, releasing the rocket.
Make a spring to hold the trigger mechanism in place. Cut the third 2-liter bottle along the lines of the product label. Remove the label and gently flatten the circle of plastic. Place the 1 1/2-inch trigger pipe on top of it and trace the inside of that pipe on the plastic. Repeat on the other side, and cut out the circles. Slip this piece over the 48-inch pipe from the end to the hose clamp that holds the zip ties. Make sure the other end is below the heads of the zip ties. Slide the 1 1/2 inch pipe onto the 48-inch pipe above it and thread the twine through the center of the spring. The plastic spring will prevent the trigger from sliding down until you pull it.
Place your rocket on the end of the launcher and lock it into the trigger mechanism. Tape the twine to the bottom of the 48-inch pipe so it is neither loose nor pulled tight.
Place the remaining 22-inch PVC pipe next to the 48-inch piece so the end is just below the hose clamp. Tape it in place. This will prevent the spring from sliding past the hose clamp and also strengthen the long pipe for launching.
Launch the rocket
Put about 1 liter of water in the rocket.
Place the rocket on the launcher and press it onto the seal. Make sure the trigger mechanism is attached to the rocket.
Attach the air pump to the tire valve.
Hold the launcher so it points straight up. Pump air into the launcher until it is pressurized to about 60 pounds per square inch. Do not pressurize it above 70 pounds per square inch as the bottle may explode.
Pull the trigger. After each launch, empty the pipes of water.