This blog covers the day to day progress of water rocket development by the Air Command Water Rockets team. It is also a facility for people to provide feedback and ask questions.

Friday, June 20, 2008

Side Deployment Construction Tutorial

Construction details of how we make our side deployment mechanisms are available here:

We have been using this technique on our rockets for more than a year now. But finally got around to documenting it. All the materials used are readily available and it can be adapted to things like Tomy timers and the like.


Monday, June 16, 2008

First trials of new staging mechanism

Over the last few months we have been slowly working on a new staging mechanism. On Sunday we spent some time completing it and running through some initial trials. We test fired it 3 times, at 60psi, 100psi and 120psi. We did the tests just in the back yard with only bottles connected rather than real rockets. We were pretty happy with the performance after a few adjustments.

Next we are going to build a very small second stage (~600mL), and a small booster - likely to be just a spliced pair of bottles. We want it fairly small so that it does not leave the local park. We want to see how it will go in flight before it is put on a bigger rocket with a bigger booster. This staging mechanism will eventually go on the Acceleron rocket, but could be used for a third stage on the Polaron rocket as well.

A full write-up with diagrams of the internal operation will be posted on our main site once we have done the test flights and had a chance to evaluate its performance. Weighing in at 94 grams it is a bit on the heavy side for small rockets, but for bigger rockets it won't make much difference. Acceleron's V's staging pod weighed in at over 400 grams, but also included the parachute bay.

Wednesday, June 11, 2008

Weekend Work

We worked on a number of different projects this weekend. We started a small production run of nosecones with integrated deployment systems using the new V1.5 flight computer. The idea is to build a number of these nosecones into our inventory so that we can simply screw in a new one should one become damaged. This will allow us to continue development on new projects without the need to spend a lot of time on repairs.

We also fixed up the launch release mechanism on the medium launcher after a hairline crack developed in the riser air tube. We have replaced it with a shorter much sturdier pipe that can be unscrewed. We also built a couple of swappable release heads with integrated launch tubes. The release head fitted to the release mechanism (image below) is a standard 9mm nozzle. The other two release heads are 15mm nozzles one with a 26cm launch tube to go into single bottle or robinson coupled rockets and the other has a 112cm launch tube to be used with longer, Tornado coupled and FTC rockets.

We've also did some more work on the new staging mechanism, but mostly just epoxying parts together.

We've fitted the endcap and nozzle on a full length of FTC now as we really want to get this first FTC rocket test flown. It will be launched with the new long launch tube shown above. There is still quite a bit of work to do especially on the recovery system.

Wednesday, June 04, 2008

Flight Computer V1.5

The full construction details of V1.5 are now available here:

Features include:

  • Dual RC servo motor control
  • 7-segment LED display indicating status information
  • Built in launch detect G-switch
  • External launch detect / burnout / negative-G trigger input
  • Buzzer for indicating status and helping to locate lost rocket in tall bushes
  • EEPROM used to store settings while power is turned off
  • 15 configurable control parameters
  • Altimeter/auxiliary power connector

The update includes a short video of the operation, as well as circuit diagrams and PCB layout.
We've got 10 boards done now and are in the process of populating 5 of them with components. We'll be switching all our rockets to these over the coming weeks as we put this version through various trials.


Monday, June 02, 2008

Polaron VI to 637 feet

We had another great day this weekend launching rockets at the NSWRA launch meet. There was a unique opportunity to launch during a fog to see if we could get video from above it, and we managed to get a personal best altitude with our Polaron VI rocket on another flight.

Full details, photos and a highlights video of the day is available here: