2 stage rocket

Rocketry that will literally wet the appetite

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kitestring
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2 stage rocket

Postby kitestring » Fri Feb 05, 2016 5:58 pm

Update to 2 stage rocket
After a failure with a 2 stage rocket launch last month, I have modified the clamp system with extensions. The previous failures were caused by the sleeve distorting under pressure from the upper stage and allowing the clamp to release. The plastic extension arms are designed to clamp to the upper stage which has a firm shape and should not allow prematurely release... Here's hoping. Will try again at feb launch.
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kitestring
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Re: 2 stage rocket

Postby kitestring » Mon Feb 15, 2016 7:53 am

Update from Feb Launch.
2 stage mechanism successful. Drogue chute failed to open main and second stage chute failed. But happy the idea worked. Very low altitude initially. The aim is to add the second stage to a dual drop away booster. Maybe at April launch.
Video of water rocket launches including 2 stage trial at QRS site: https://www.youtube.com/watch?v=7UMtOOg0C_k

october sky
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Re: 2 stage rocket

Postby october sky » Tue Feb 16, 2016 4:59 pm

Great work Jeremy....cool videos ! Hope you could demonstrate some of your handi work at the March Open Day launch also. :)
QRS Inc. NO: 003

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kitestring
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Re: 2 stage rocket

Postby kitestring » Tue Feb 16, 2016 5:27 pm

october sky wrote:Great work Jeremy....cool videos ! Hope you could demonstrate some of your handi work at the March Open Day launch also. :)

Thank you! Hope to do a rocket with drop-away boosters. Nothing like what Aircommand does, as I'll never be in that league, but it should still demonstrate the principal.... if it works. Last public day didn't go so well, but i guess that's rocketry
See you there :D

air.command
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Re: 2 stage rocket

Postby air.command » Tue Feb 16, 2016 9:09 pm

Great video Jeremy! :D thanks for posting. It looked like you got some pretty decent altitude too, and great to see the stager working. As you mentioned in the YT comments I think adjusting the timing on the staging Tomy timer should be fairly easy. Do you know how long it takes from the time the timer releases the rubber band to the time the stager actually releases the sustainer? You may be able to get accurate timing from the video if you step it frame by frame and see how long it took until you got burnout after launch. Also what size nozzle did you use on the booster?

- George
Crop Circles: ... just a bunch of guys looking for their rockets ....

kitestring
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Re: 2 stage rocket

Postby kitestring » Wed Feb 17, 2016 11:33 am

air.command wrote:Great video Jeremy! :D thanks for posting. It looked like you got some pretty decent altitude too, and great to see the stager working. As you mentioned in the YT comments I think adjusting the timing on the staging Tomy timer should be fairly easy. Do you know how long it takes from the time the timer releases the rubber band to the time the stager actually releases the sustainer? You may be able to get accurate timing from the video if you step it frame by frame and see how long it took until you got burnout after launch. Also what size nozzle did you use on the booster?

- George

Thanks George
Altitude will be better next time hopefully. Most launches are only around 80-95psi. Supposed to be 110+ but seem to get a dramatic sudden loss of pressure around 80, then it builds again. Trying to find time to work out why.
Am using tommy timer release mech from Raketfued Rockets. It's great and rugged except its hard to make fine adjustments. There are only 2 points to anchor/wedge. So may remake this section with 4star pins which give 1+- sec increments.
The main stage timer was set for approx 2 secs (when elastic band starts to unravel-vid confirms). 2nd stage set for 4 secs but that didn't work at all... boohoo! Another rebuild.
Nozzle was 9mm. Definitely change to 16mm next time or full throttle. Its a bit of a guessing game.


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