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, February 12, 2010

Pressure tests

After a week of curing, yesterday dad hydro tested 5 of the new splices to go into Acceleron V. These ones had a slightly narrower sleeve than the previous 4 for ease of manufacture. The results were all good with the test having the splices hold 140psi for 30 seconds. There were no leaks and no visible stress marks.

I'm happy with the yield rate so far for these splices. We haven't had any leaks in the 10 we have made to date. I'm sure there will be the occasional one that will leak or fail, but so far it's a good start.

We now have enough of the splices to put Acceleron V back together again. We will do a nozzle seal check next by placing the lowest bottles with nozzles on the launcher held down via the baseplate and checking to make sure the new nozzle seals are good. We won't need to remove the nozzles after the test.

Because the new pressure switch is only a SPST type, we can't wire it directly to an LED like last time to tell us that enough pressure is in the booster. When this LED was ON (@~20psi) we knew the switch was activated and the flight computer was safe to arm. I'm going to update the software in the primary computer to give us a pressure switch status indication on the LED display so that we can tell when it's safe to arm it. Although we could get it to arm automatically when the pressure switch activates, I still prefer to keep the human-in-the-loop for these kinds of things in case we need to abort the launch.

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