Tape for small dual deployment


Want to do a G or < size dual deployment model that uses heavy cardboard tubes. Instead of shear pins I thought if clear shipping tape might be workable to hold the electronics section together to the upper or lower section. Also which section contains the drogue or does it matter which blows first? I thought the upper section would contain the drogue and lower the main. Anyhow I want to do a smaller model as I have a smaller field to fly from. I also saw some of the larger models using it and it looks cool. Acquire the skills on a smaller model and when going to level II it might not be so traumatic.

Kurt Savegnago

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If the rocket is light emough all you have is break it in half at apogee and let to fall that way until you want it to deploy the main, which I would do out the nose with.

Reply to
John Karpich

I watched about 15 or 20 dual deployment launches a couple of weeks ago at Southern Thunder and generally noticed they were all designed to break in the middle of the rocket. For the most part each section fell horizontally and when the main chute came out with the nose cone it didn't have any chance of tangling in the shroud lines or shock cord because it was facing away from them when the second ejection charge blew.


Reply to
Andrew Grippo

The reason they are broken in the middle is so that the opening shock of the drogue does not cause the rocket to separate. If the drogue deploys out the nosecone, the weight of the booster will cause the rocket to separate in the middle. If the drogue deploys out the middle, the nosecones usually does not have enough mass to separate until the main charge fires.

Which ever method you decide to use to hold the rocket together, ground test the charges to make sure you can separate the rocket and get your parachutes out. Better to learn on the ground you needed another gram of black powder than in the air!

Erik Gates

Reply to
Erik Gates

Another good reason to have the drogue on the bottom and the main on the top so you can use the motor ejection for backup. Use a long delay motor and if you have an electronics failure the drogue will still deploy. It may land hard but it will prevent a lawn dart.


Reply to
David Bacque

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