2 stage deployment

[rvanstone]

Folks

I have been think of creating a scratch rocket and want to use a 2 stage delpoyment scheme .

So I confused, but that's nothing new.
Anyway I have a diagram of what I think the setup should look like.
I don't want the top airframe separating until I have the altimeter deploy a BP.
I am thinking of using plastic rivets. Should I use A & B or just A



Ron

 

[llickteig1]

Ron,

If the rocket is 4" or less and you're planning on staying under mach, I wouldn't use any. Just make sure both sides of the coupler are good and tight, add small vent holes to each compartment, and use long recovery harnesses. Worst case, use the rivets only of the main 'chute side (A) to prevent the drogue ejection from yanking the main compartment open. At B, you're preventing drag seperation: not usually a big problem in 3FNC or 4FNC rockets with proper venting and tight couplers.

I also might suggest that with this configuration you run long wires from your electronics to the ends away from the open ends of the airframe so you're blowing the 'chutes out of the airframe. That is, put the charges near the top of the motor and near the nose cone. When splitting the rocket in the middle with ejection charges in the middle, you can blow everything back into the airframe and get it packed in to tight resulting in no or only partial deployment.

If the rocket is bigger, use rivets both places. Lots of air in there expanding and contracting.

Just my thoughts. YMMV, --Lance.

 

[rvanstone]

Lance,

I see your point on placing the charge at the other end of the airframe Thanks .
So this rocket is definitely 3 inches in diameter .
So If I have the possiblity of hitting mach I should use rivets ?
I will check RockSim for velocity .




Ron

 

[llickteig1]

This doesn't look like a high-performance rocket to me, but if you want to be ultra-safe, then you can use rivets. I just don't think I would. The only thing worse than your rocket coming apart early is having it not come apart at all. You can add the rivets any time, even after a few flights if you feel the need.

Rivets or not, make sure you test everything on the ground to make sure you're using adequate ejection charges to blast everyting apart.

Buena suerte, --Lance.

 

[rocketsonly]

Is there a 2 stage kit out there?
-Matthew

 

[rvanstone]

If you are referring to a 2 stage deployment yes.
Public Missiles makes them, check out the Amraam series.
Gotta have some bucks though.

I don't know of any 2 stage rockets sold has kits though

Ron

 

[Ryan S.]

you can buy them from many manufacterers mainly all you need is a rocket with a payload bay.

I would just glue, or screw your coupler into the payload bay and then maybe use rivets on the NC

 

[rvanstone]

Folks,
Here is the rocksim file I design , its base on the Phoenix

Ron