Launch Cage Test Day

We were fairly keen to try out the new launch cage so even though it was 33 degrees C (50 degrees C on the asphalt) last Sunday, we ventured out to our local launch  site to test the water rocket car with the new launch cage at launch pressures.

The water rocket car had the reinforced triple stack of bottles attached, which have been tested to 180psi. We also had the upgraded launcher using the high pressure hose, both of which hadn’t been run on the car before.

We were also trying out the new MD80 Camera which is a light camera mounted to the water rocket car.

The aim of the test day was to see how the car would launch out of the cage, if it was sticking in the guide rail or not launching straight. Here is the video of the launch day.

Results
Its not shown on the videos, but we did do a 60pis test and an 80 psi test before doing the 120 psi & 125psi tests. The 60psi and 80psi tests worked fine so we increased the pressure up to launch pressures. We didn’t include the video of these launches as they were not really all that  spectacular :)

We were pretty happy with the results of the cage test. The car on both high pressure launches is leaving the cage straight and there doesn’t appear to be any major loss of speed due to friction using the guide rail. There doesn’t appear to be any recoil of the cage and launcher and the cage held together well on launch. Getting the cage to the launch site also worked well, only issue was some strangle looks we got on the way there ;)

The MD80 camera worked ok, but we still have a few teething issues to work through as the first run didn’t record, or most likely, the second video recorded over the first one. We will work on that and possibly download videos from the camera between runs using a laptop, just to be sure.

The car once it left the cage was turning left, this was most likely just a slightly sticking front wheel, the wheel bearings were not greased before this test as we were not going for distance, which would account for the minimal rolling distance as well as the left turn. This should be easily fixed.

Here are a couple of video images showing the water rocket car launching. One of these is now posted on the dragstrer competition page on www.wra2.org , the page is here

Launch 2 - 125psi, very clean exit form the launch cage

Launch 1 - 120psi, nice exhaust plume when leaving the cage

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This entry was posted on Wednesday, February 2nd, 2011 at 11:44 pm and is filed under Launch Days. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

 
 

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