Introduction: Water Rocket Launch Pad


This is my first attempt to write an Instructable, So let me introduce you the Water Rocket launch pad that I made for and with my kids (I use it too because it is very fun!).


For the frame

wood 38x38mm:

  • 400mm x 4 (for the base frame)
  • 150-200mm x4 (for the feet)


  • 5x80mm x4
  • 5x50mm x4
  • 4x60mm x4
  • 10mm hook x2

For the mechanism

  • cooper pipe diam 16mm long 70mm
  • cooper pipe diam 16mm long 200mm
  • copper pipe diam 22mm long 125mm
  • cooper reducing coupling 28-22mm F/F x 1
  • cooper reducing coupling 22-16mm F/F x 1
  • cooper 90 degree elbow diam 16mm F/F x 1
  • brass adapter diam 16mm F to 20/27 F
  • valve 20/27 F/F
  • air plug 20/27 M
  • cable tie x 12 (with the small 3x3mm head)
  • PVC pipe diam 40mm x 50mm
  • PVC conduit diam 16mm x 200mm with female connector
  • String
  • PTFE tape
  • Double-sided tape
  • Electrical tape

Step 1: Frame Assembly

First, we will need make a "H" with the 4 part of 400mm.

To do that, join 2 part of wood by screwing them together then drill a 25mm hole in the center of the piece so we could hold the cooper pipe. After that, you could screw the of pieces of wood by the center on the extremity of the joined pieces.

For the feets, cut a 30 degree bevel at one end of each, and screw them to the extremity of the "H".

Step 2: The Mechanism

For the mechanism, I used old copper pipes and some fittings that I had in my plumber tool box, I only bought the 28/22 reducing coupling, it fits perfectly to the bottleneck of most bottles of soda.

Weld the pipes like on the picture.

Put double-sided tape to hold the cable tie while placing them, (I put a bottle temporarily to check if they was fitting well) and when they are all good, fix them with electrical tape.

To make the lock ring, take a 40mm PVC pipe, made two small hole, pass a string of about 300/400mm in them and made knot on each side to hold them to have a kind of loop.

Step 3: Assembling the Frame and the Mechanism

To assemble the mechanism with the frame, remove one of the "H" middle bar, put the mechanism in place and put back the middle bar.

In my case, the 25mm hole I made was too "big", the copper pipe there was 22mm and I put the cable tie all the way around, I thought 25 was good, but it was too big so I had to put more electrical tape to enlarge the diameter of the pipe and tighten it well between the wood pieces

Place the 10mm hook on each side of the pipe, place the string inside so that could act as a lever. When you pull the string that pull the ring down and liberate the cables tie and finally the bottle.

Step 4: Time to Try...

Ok, it is finished? Not yet!
Take a long string and attach it to the loop made with the small one atteched to the lock ring.

Fill half of the soda bottle with watter, put it in place in the cooper reducing coupling and puch up the lock ring.

Put the launch pad in place then fix it to the ground with rods.

Put the string of the lock ring in the hooks and plug in the compressor.

We are done! let's GO Open the valve, take some distance and 4, 3, 2, 1... pull the string!

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