Building a Homemade Water Rocket Launcher


Supplies You’ll Need

  • a plastic cork (to fit into a 2-liter bottle. This is most of your launcher, right here!)

  • 25 feet of 1/4-inch diameter polyethylene or vinyl plastic tubing (available at your local building supplies store!)
  • a roll of ¾ inch wide masking tape (for making the bicycle pump adapter!)
  • the parts for the homemade water rocket launcher

    Tools You’ll Need For Your Water Rocket Launcher

    • a pointy screwdriver (for poking a hole in the cork!) Philips or Robertson type, but not a slot screwdriver!
    • a retractable blade X-acto knife (for cutting the tubing!)
    tools for the homemade water rocket launcher assembly, screwdriver and exacto blade

    This is a plastic cork that is designed to fit snugly into the mouth of a 2-liter plastic pop bottle. It will be the nozzle release mechanism for the launcher.

    cork for the launcher

    Use the screwdriver to poke a hole lengthwise right through the cork. The shaft of the screwdriver should be as wide or wider than your polyethylene tubing diameter. Be very careful when you are poking this hole so you don’t poke yourself!

    putting a hole in the cork

    You may have to wiggle the screwdriver a bit to get it all the way through the cork.

    the screwdriver has made a hole in the cork

    Sharpen the end of the tubing by cutting off a bit of the end at a sharp angle. This makes it easier to push into the cork later on.

    sharpening the end of the tubing

    This is what the sharpened end of the tubing should look like.

    the sharpened end of the tubing

    Push the sharpened end of the tubing into the hole in the cork. You have to do this quickly because the hole is gradually closing back up again. This is how the cork holds very tightly onto the tubing.

    the tubing and cork

    When the tubing has been pushed through the cork, it should look something like this. If you weren’t able to push the tubing all the way through the cork, that’s okay. It will work as long as you pushed it at least halfway through.

    pushing the sharpened tubing through the cork

    Carefully wrap a length of masking tape around the other end of the tubing until its diameter is wide enough to fit snugly into the bicycle pump’s open connector. If the rolled tape won’t fit in, unroll and remove a layer or two. If it’s too loose, get another piece of tape and put on a few more wraps.

    taping the end of the tubing

    Your finished launcher should look like this. When you launch your rocket, the green end will attach to the bicycle air pump connector and the cork will fit into the mouth of the rocket bottle.

    the finished launcherSee you at Lesson 4: Launching Your Homemade Water Rocket!