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.

Saturday, December 15, 2007

Fire and Water details available

We have updated the main site with the details of the launch event from last Saturday. The update includes a video of the highlights.


Monday, December 10, 2007

Fire and Water

We had a great launch day event yesterday. We met up with a couple of pyro guys from the Australian Rocketry forum and the weather at the new launch site co-operated as well. We did a total of five flights (all with on-board video) and they too launched a number of theirs. We also did a combined effort and strapped our video camera to the side of one of their rockets. It's interesting to see how similar the view is from both types of rockets, especially when using foam in the water rocket.

I was fascinated to see their pyro rockets close up, and the preparations needed to get them going. The pyro rockets sure are a lot less messy. Ultimately the same parameters apply to both disciplines in terms of drag, stability, thrust etc.

The new George Kendall Reserve launch site was also very good. There were only a few people about and the clearance range is greater compared to our usual launch site. Being only about 35 minute drive from home is not bad. It's definitely a place to test the next stage of development.

Over the next few days I will do a full web update with photos and videos again.


Monday, December 03, 2007

Polaron IV progress

We didn't get to fly this weekend due to the adverse weather conditions, but at least we made progress on the Polaron IV rocket. The 8L rocket main stage pressure vessel is now finished, with reinforcement of the bottle bases based on the technique described during our last update. We had to machine up a new base to base coupling that was longer than normal because it has to go through 4 thick PET walls with washers in between. When we now heat shrink the reinforcing sleeves, we fill the inner bottle completely with water and pressurise it to about 15psi. We also use a blow torch set to a low flame to get better control over the heating location.

We have yet to pressure test the main stage, but I am hoping that 130psi will be a safe launch pressure. After a couple of failures at 120psi of similar Robinson coupled 2-liter bottles, we have been reluctant to push the pressures much higher. Hopefully this reinforcement technique will allow us to do that.

We have also started modeling some of the launcher components and staging mechanisms in 3DStudio Max to get a better idea how it's all going to fit together. It also allows us to check for clearances before cutting any metal.

Dad has also prepared hoses and another pressure regulator that goes up to 25 bar (~360psi) with the associated high and low pressure gauges. This will allow us to launch a rocket with a different pressure to that of the boosters. This way we can optimize the performance depending on the structural integrity of the different elements.