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Fast airstart ignition of K550W ? ?

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DMcCauley

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Anyone have any recommendations on how to quickly (and reliably) fast start a K550W without having to make a thermite mixture?

Basically, i'll be airstarting (2) K550Ws using a breakwire timer device (PerfectFlight) which will need to initiate just after the central M650W motor ignites and the rocket starts moving.

Thanks
Dan
 

highpowerrocket

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Pyrodex pellet is an excellent way to go. Another option is to dip an electric match in pyrogen and attach a small sliver (or two) of Blue Thunder propellent to the igniter with thread.
 

FROB

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Tell me about it- i just discovered i could make decent propellant from dollar store "ingredients" :D:D:D gotta love it:cool:
 

ben_ullman

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Tell me about it- i just discovered i could make decent propellant from dollar store "ingredients" :D:D gotta love it:cool:
just wait untill you realize how awesome HTPB propellants are ;)

Ben
 

cjl

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I've had excellent success with the slivers of blue thunder method. I just use an F39, and cut the grain lengthwise into 5 or 6 slivers of propellant. Add 1 or 2 to your igniter, and it WILL light, nearly instantly.
 

DMcCauley

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Will an electric match light the blue thunder slivers instantly?
 

cjl

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Not reliably, unless it is dipped. They aren't hard to light, but I wouldn't trust them to light on something as quick as an e-match.
 

ben_ullman

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Not reliably, unless it is dipped. They aren't hard to light, but I wouldn't trust them to light on something as quick as an e-match.
Unless you get the Ematches the BURN not POP. Then you have a good chance.

Ben
 

cjl

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Unless you get the Ematches the BURN not POP. Then you have a good chance.

Ben
E-matches pop. It's how they work.

Yes, some pop slower than others, but they will never burn as slowly as a typical igniter.
 

ben_ullman

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E-matches pop. It's how they work.

Yes, some pop slower than others, but they will never burn as slowly as a typical igniter.
I know the Davey Fires Hold fire long enough to light slivers and pellets. They hold fire longer than say an Mtek

Ben
 

cjl

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Well, if by pellets you mean pyrodex, it is quite easy to light. Any e-match will do. Propellant slivers are harder to light though, at least from my experience.
 
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