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, March 20, 2009

Parachute Detachment Mechanism

In chatting to Mat G. this week, he described how his rocket got stuck in a tree flying one of the computers. I thought that the FC should at least be able to try to help in such a situation. Snagging a parachute on trees is a very common problem, especially when the wind carries the rocket beyond the designated range.

We put together a Parachute Detachment Mechanism prototype (DetMech) that allows the rocket to automatically let go of the parachute cord after a predetermined time.

The full details of the mechanism are available here:

We want to test fly it next to see how the clamp holds up under high speed deploys. ... yup just another excuse to fly more rockets. :)


Wednesday, March 18, 2009

FC V2.0 Development

With the last of V1.6 sold yesterday, we are using the proceeds of the sales on the development of the next version of the FC. The new version is quite different and includes a lot of new functionality some of which is intended for use on pyro rockets.

We are also aiming to reduce the overall footprint and weight of the FC by using surface mount components. Circuit design is about 2/3rds done but the software spec for this version is only about 1/4 complete. The core is still based around the PIC16F628A but will have a few more support chips to offload some of the functionality.

The expected time to completion is likely to be around 6 months as there is a lot of new code to write, but that may be pushed back further depending on time allocation priorities on all other projects currently under way. I'll post progress updates and more details when significant milestones are achieved.


Monday, March 16, 2009

Flour Rockets

We've had a bit of fun this weekend with the kids launching rockets powered with flour rather than water.

The full write up of the days events is here:

Included are photos and a highlights video.


Saturday, March 14, 2009

Variable Nozzle Testing

This weekend we pulled out the static test stand and continued with more testing. Before the tests we spent a couple of hours making the flexible nozzle membranes and the tools to make them.
Dad machined up the stamp tool that cuts the membrane out of the rubber sheet to the exact size (the brass component), and then the hole punch alignment tool, that allowed us to center the hole punch in exactly the middle.

We ran about 14 tests with different materials and different sized holes. We haven't had a proper look at the data yet, as that will again take a couple of weeks to analyze and write up. One interesting surprise we did get was during one particular test the nozzle made a pretty loud whistling noise. We might fly that one on the next launch day just for fun.

We'll post the full data on the nozzles when the analysis is complete.

Tuesday, March 03, 2009

Day 73 - Highlights

We've posted an update on our main website with the highlights from day 73. The update includes photos and a video of the days' events.

.... now it's back to the workshop....

Sunday, March 01, 2009

2 great flights, 2 crashes

We had an overall great day at NSWRA's launch event on Saturday. We got to fly the newly rebuilt Polaron VIb rocket that hadn't flown since May last year. Both flights were almost perfect with very nice vertical flights, and no spin which made for great stable ascent video. Although we had tested the bottles to 130psi, we only launched at 120psi to be on the safe side. During testing earlier in the week, we had 3 out of 4 spliced-pairs leak. So only the bottles that had withstood the full 130psi were used in the rocket. We were very happy with the performance of the rocket, and were glad that the stability improving changes we made had been effective.

While other NSWRA members were drilling holes in the clouds (literally) with their impressive pyro rockets we were busy taking core samples near the launch pad. One was the FTC rocket and the other was Axion II. Full details of the crashes will also go in the update.