Launch Day 4

Planned Launches

  • Tango Ia from stager with restricted black 9mm nozzle at pressure 35psi with 250ml of water
  • Tango II at 35psi with 300ml of water to test chute
  • Tango III at 35psi 1st stage 250ml, 2nd stage 300ml water
  • Tango Ia with restricted 9mm green nozzle at 50 psi with 250ml water.

I was pressed for time due to only having a bit of free time at the end of day and there isn’t much daylight this time of year. So I went and forgot to take anything to measure the water out so I think I under filled the rockets which might of been the cause of some failures.

First launch was to test that stager released the second stage when the first stage loses pressure. It was also to test that the second stage would pull out the parachute of the first stage. So the rocket was pressurised and then released the pressure from the first stage. This does pose a problem for launch aborts.

Second launch was to test parachute deployment of final stage. I think due to underfilling the rocket there was not enough flight to for the deployment.

Launch 3 was to test the stager in a actual launch.

Future parachute deployment tests will be done at higher pressures with enough water to give a chance for the parachute to deploy.

Chute deployment 2

Since it didn’t work to well on the first attempt I thought a bit of a redesign was in order. The core device is the same, the difference is that it has a seperate parachute compartment ahead of it and the nose cone is pushed of by a rod connected to the device.

Ground test went well.

Filming Checklist

  • Set video camera to record at 8x Zoom
  • Turn vivitar
  • Set vivitar to video
  • Set vivitar to 4x Zoom
  • Turn on Casio check video setting
  • Set to 3x zoom
  • Turn on ActionCam
  • Start recording on video Cam, Actioncam,Vivitar,Casio
  • Point at launcher wait for focus
  • Check framing on Casio
  • Record for a few seconds
  • Try to find rocket and follow.

Flight Camera

I bought this with the intention to fly it on the rockets to get inflight video footage. I bought this one as it was small, light, cheap and also it has the choice by a slide switch that it can take either video or photos. So when I add a flight computer I can take higher resolution photos than the video clips which are 720*480. Although I have since read on the internet that the sensor might only be 640*480 I’ll have to take a close look a the photos it takes.

As bought.

The insides after I’ve soldered some wires to the switch so it can be controlled by a flight computer or just easier to start it recording when it in the rocket.

Put back together with the wires glue so not to strain the solder joint.

Now I need to be able to bring a rocket back down softly so I can fly it.

Launch Day 3

Planned Launches

  • Tango II full bore at a 35psi with 300ml of water
  • Tango Ia full bore at a range of pressures starting at 40psi with 250ml of water
  • Tango Ia with restricted 9mm nozzle at a range of pressures starting at 30psi with 250ml of water

Decide to try a few launches late in the day and since I had little light left I only took a video off the TangoII launch. Which was to test the parachute deployment.

The deployment device appeared to work, but the parachute didn’t eject properly and catch the air.

Did a succesful launch of the Tango Ia at 40 psi full bore nozzle.

Attempted a launch of Tango Ia at 35psi with the restricted 9mm nozzle but it didn’t release. Then tried at 45psi and launched successfully. So at least the glue on the nozzle holds up at 45psi.

Launch Day 2

Planned launches

  • Tango Ia full bore at a range of pressures starting at 35psi with 250ml of water
  • Tango Ib full bore at a range of pressures starting at 35psi with 250ml of water
  • Tango Ia or Ib with restricted 9mm nozzle at a range of pressures starting at 30psi with 250ml of water
  • Tango Ia or Ib with restricted 6mm nozzle at a range of pressures starting at 35psi with 250ml of water
  • Tango II full bore at a 40psi with 300ml of water


  • Casio ex static tripod
  • ActionCam on handheld mount
  • Vivitar Vivicam5188 on handheld mount

It seems the Actioncam doesn’t like rechargables which is what I took with me so I wasn’t able to use it.

Tango Ib launch
250ml of water at 35psi with full bore nozzle.

I forgot to change the Vivitar camera to video and since I wasn’t able to use the actioncam either I didn’t get any flight or landing footage. Which was a shame since it’s flight was a bit twisty and the fins flew off on landing. Otherwise it was a good flight.

Tango Ia launch
250ml of water at 40psi with full bore nozzle.

This time I remembered to change the Vivitar to video. Straight flight and the wings stayed intact.

Then the pump broke 🙁

Chute deployment

This came out of the stager work.

When the pressure drops the inner tube stops gripping the tube which allows a rubberband to push the nose cone up.

Needed a method to introduce a delay of the pressure after burn out to allow for the rocket to coast before the chute is deployed.

Tango I

  • Volume 700ml
  • Mass approx 50g +25g nose weight
  • Diameter 67mm

Painted orange so it should be easier to keep track of.

Tango Ia with restricted nozzle

Tango Ia center of gravity was to far to the rear of the rocket so the nose will need to be weighted.

Tango Ib

Alternative fine arrangement with the fins glued to the body which proved difficult to align while glueing.

Stager MkI

There nothing like trying to run before you can walk so I’ve started making a stager so I can have multiple stage water rockets. I’ve first intended to make one using the Air Command Water Rockets design, but I decided I wanted it to work by loss of pressure instead of loss of acceration.

Started out be removing the spring and cutting of the hose grip of a hose connector (b&q value one).

Overflow pipe make a really nice tight fit into where the hose would go. The bottle top make a nice fit into 32mm Waste pipe, which fits fairly well into 40mm waste pipe.

The spring will hold the connector open and the inner tube will inflate gripping the 40mm pipe which will be attached to the connecter to hold it in the close position. There’s a hole drilled into the inner pipe to allow the inner tube to inflate.

I cut the overflow pipe to short so I decided to use it to test the inflation. I used a 2 part epoxy to glue the bottle necks and connector to the overflow pipe after first roughing the surfaces with sand paper.

The ends of the inner tube were glued to the overflow pipe and also wire wrapped to further strengthen the join and some inner tube put over the wire to lessen the chances of it puncturing the inner tube.

Inflation test.

The stager grips the tube at 15psi and currently tested up to 25psi.

An alternative design would be to leave the spring out and have rubber bands on the outside pulling the outer tube down. This would be a little easier to make and also be metal free.