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.

Tuesday, November 06, 2007


This week we continued working on the stager mechanism. We finished enough of it to test it staging just in the back yard. We used only air at 20psi a couple of times and at 50psi once. Although it worked it was a little stiff to release and that is something we need to look at. We will probably try softer o-rings first. We still have a major design issue to resolve, but have some ideas. (More on this later)

The camera that wasn't behaving during the last launch day appears to be OK, and the cause looks like a poor battery contact. The contacts must have become more compressed inside the camera. We tried it with another battery that has taller solder blobs on the contacts and that worked fine, even when shaking the camera.

We also had a go at building the first prototype of the shock absorbing nosecone. It basically consists of the top 3/4 of a PET bottle which is filled with soft foam. The sides of the bottle have 8 longitudinal cuts all the way around that allow the bottle to easily split and slide over the existing nosecone. It is lightly taped over the top to enable the tape to separate easily on impact. During a crash the padded nosecone slides down and the foam compresses against the internal nosecone, but also the whole thing acts as an air piston to dampen the shock even more. The prototype weighs 35 grams so not a very significant weight penalty. For record flights, this can be removed and the existing nosecone underneath can just be used.

We have also been on the lookout for new launch sites around Sydney with great help from the local rocketry community. We looked at one location (George Kendall Reserve) that looks pretty good and is only about half hour from home.


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