Co2 vs black powder

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Billiam

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Has anyone ever attempted a Co2 powered deploy rather than a black powder deployment charge?
 

Billiam

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I see that the Rouse Tech CD3 and the Peregrine still require e matches and black powder! Is there no other way to release the Co2 pressure?
 

RAHagen

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Hey sorry to jack this thread but I have a question that I've had some trouble finding info about. I read that co2 ejection systems have only been tested to pressures equal to 80000 feet, but I'm curious, has anyone flown them above that?
 

dhbarr

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What about some sort of trigger and puncture pin?
Look at the mechanisms for inflating life jackets, rafts, etc. Fairly straightforward, and amazing QC.
 

rocket_troy

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Hey sorry to jack this thread but I have a question that I've had some trouble finding info about. I read that co2 ejection systems have only been tested to pressures equal to 80000 feet, but I'm curious, has anyone flown them above that?
I can't provide any particular references, but I'm pretty sure someone/few people have. I remember Jeff Taylor and Curt Newport went pretty high with CO2 deployment going back a few years.
CO2 should actually perform *better* at high altitude than low as the propulsive efficiency of the gas is significantly improved. The problem with BP at altitude is nothing to do with the propulsive efficiency or effectiveness of the gas produced, it's the actual *combustion* of the BP itself at reduced pressures. Again, it's a problem solved by suitable containment of the charge.
 

rocket_troy

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What about some sort of trigger and puncture pin?
The primary reasons why pyrotechnic driven puncture is so common with commercial CO2 devices is (1) simplicity of the design and (2) you need significant power to puncture the bulb to ensure you achieve maximum throughput from the bulb. Remember, the diaphragm to be punctured is generally of a very small area of itself and it needs to withstand well over 1000psi pressures (a CO2 bulb will get well beyond that on a hot day) which translates to a reasonably strong material to puncture. So, not only do you need the power to puncture the diaphragm, you need to puncture it as widely as possible to maximise the flow through the puncture to increase the reliability of a successful deployment ie. more throughput=more deployment power.
 
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Billiam

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rocket_troy, you make some good points, but since the opening of a Co2 bulb is roughly 1 to 1.5 square mm, that translates to roughly 1.5 lbs per square millimeter. Certainly able to be punctured with a relatively small amount of force.

1 square inch = 645 square millimeters
1000 psi (pounds per square inch) = 1.55 psmm (pounds per square millimeter)
 

ChrisAttebery

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I can tell you that it takes about 100 lbs of pressure to puncture a CO2 canister with a .090" hole. You need to pierce a .008" sheet of steel. Leland specifies 70lbs to break the seal, but they don't specify the hole size.

Here's test of an upcoming product for the UAV market from Fruity Chutes:
[YOUTUBE]pUE4Iz-d3Q0[/YOUTUBE]
 
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