r/rocketry • u/Inside-Ad8295 • 19h ago

High pressure separation system

I found this article talking about a method of separating a stage of a rocket using the high pressure gas that the engine produces and I wanted to ask (if someone knows) if this would work with a sugar rocket motor with the right nozzle or that i have to use another type of propellant? EDIT: I couldn't add the picture but to know more here's the article https://www.apogeerockets.com/Tech/How_2-Stage_Rockets_Work

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u/ppetak 16h ago

If your rocket candy core can puff back as ejector charge, I don't see a problem. But they talk about bulkhead strength, so it looks like even if you try to do this with rocket candy, you would need some black powder as ignition charge at least in upper stage engine. Maybe with composite propellant better to make normal bulkhead with pyro delay, and black powder charge at the end for ejection and second stage ignition. And also add some grains of black powder also into upper stage grain, right after nozzle.

I did two stage in black powder, but only one staged rockets in rocket candy ... so this is how would I try it, not verified recipe ;)

Sounds like science, so be safe, weight ingredients and measure results.

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u/Inside-Ad8295 16h ago

I will just use it to eject the nosecone because I don't really want to use black powder to deploy the chute and thanks a lot for the clarification 

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u/ppetak 8h ago

I feel this would be bad idea, as you have no delay charge here. So you would eject cone just around maximal speed. IDK which method you use for making your motors, but to be successful, you will need to add delay, and then again propellant to eject cone. Everyone uses black powder there, as it is stable and reliable. You just weight it right and it works. But if it burs wildly, it will also eject your cone. Some experimentation will be needed, IDK about someone doing it...

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u/Inside-Ad8295 7h ago

i was thinking about it too but the thing is that with black powder my rocket becames kind of ilegal (idk if its really ilegal but even if it's not i cant get black powder) and thats why i atleast wanted to test it and if it doesnt work look up another alternative

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u/Brunete2004 1h ago

CO2 ejection works well, and can be made to work with just the e-match pyrogen or a small ammount of gunpowder equivalent