Cub Scout Crafts

Crafts, projects, games, and activities ideas for cub scouts.


Make a 2L Water Bottle Rocket Launcher

Today’s craft I found on YouTube. I don’t exactly remember where I came across this craft, but that’s not important. What’s important is that it is TOTALLY AWESOME!!! Using a few cheap hardware store parts combined with what may just be lying around the house, you can make a pretty awesome Water Bottle Rocket Launcher. My kids and I had so much fun with this and in fact, the first launch almost got stuck in the branches of some HUGE palm trees we have in our front yard.


  • Empty 2L soda bottle
  • 2-4′ of 1/2″ PVC pipe
  • 4-6″ of 1″ PVC pipe
  • 1″ PVC collar
  • 1/2″ PVC 90 deg. elbow (one threaded end)
  • 1/2″ PVC threaded plug (NOT end cap)
  • 1/4″ vinyl tubing (green bag)
  • 1/4″ brass hose barb (green bag)
  • 1/4″ O-Ring (this should be small enough to fit tightly around 1/2″ PVC pipe)
  • Bike tube valve stem
  • 3 #8 screw eyes
  • Rope
  • Stakes
  • Bike Pump
  • The first thing you will need is an empty 2L soda bottle. We emptied ours the fun way: with MENTOS!!!
  • Place your soda bottle on top of your 1/2″ PVC pipe and make a mark where it ends. This is for the O-Ring.


  • Saw a small groove in the PVC pipe for the O-Ring. This will prevent the water from leaking out to much when the bottle is placed on top of the pipe.

  • Drill a 5/16″ hole through the plug and attach the hose barb. You may need to add some glue to create a tight seal.

  • Screw the plug into the elbow (if you bought the threaded type – if not, use PVC glue)

  • Glue PVC elbow onto bottom of 1/2″ PVC pipe

  • Place the 1″ collar next to the soda bottle and mark where the “lip” comes down to.
  • Cut a groove into (and partially through) the collar at this point.
  • You will place a wire of some sort in this groove to hold the rocket in place while pumping.
  • Attach collar to 1″ PVC pipe

  • Screw your 3 eye bolts into the collar below the groove

  • At this point, you may want to slide the 1″ sleeve over the 1/2″ pipe and place the bottle on and make sure your groove is in the right place for the wire to “catch” the lip of the bottle.
  • Slide your bike tube stem valve into one end of the vinyl tubing. You may need to glue it in to get a tight seal.
  • The other end of the tubing will attach to the hose barb. Again, use glue to gain a tight seal if necessary

  • Once the main assembly is put together, attach a string or rope to each eye bolt and stake it into the ground. I used a tautline hitch to tie the stakes down as it works well for this purpose and is an adjustable knot.
  • I just used a staple gun to attach the rope to my stakes. However you do so, make sure the connection is solid. On our first launch attempt, the strings weren’t attached securely enough to the stakes and the pressure from the bottle ripped the string off two stakes.
  • Fill your bottle about 1/2 to 3/4 full of water and place upside down on top of launch tube. The O-ring should keep your water from leaking out.

  • Connect the free end of the tubing to the bicycle pump

  • Take your launch pin (wire on a string) and slide it into the groove on the collar to hold the bottle in place.
  • Start pumping a few times until you can feel the pressure build up. Your bottle may rise slightly on the post.
  • Once you are ready, pull the pin out and watch your rocket soar! (The string going off to the right in the picture below is attached to our “firing pin”)


  • The vinyl tubing is not necessary if you want to attach the bike pump right at the base of the rocket. This WILL get you wet.
  • If you do choose to use the vinyl tubing, make sure the color on the tag matches the color on the bag for the hose barb. They are color-coded to show what fits together (Green is 1/4″)
  • You may want to add balsa wood or cardboard fins to your rocket with some duct tape to help stabilize it during flight. Do this to complete your model rocket for Tiger Elective #17 and Bear Elective #1d
  • I did not have a spare bicycle tube lying around so I bought one for about $5 at WalMart. Just cut out the stem, but KEEP the tubing. There are other crafts you can use it for.
  • So, if you have a spare bicycle tube and cut out the vinyl tubing, this is a VERY inexpensive craft.
Achievements Fulfilled:
  • Tiger Elective #17
  • Wolf Elective #3e
  • Bear Elective #1d
  • Webelos Craftsman #4
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1 Responseto “Make a 2L Water Bottle Rocket Launcher”


  1. Kathy Says:

    Looking forward to doing this with the boys. They’ll love it!

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