The Duel Booster Chute Scratch-build--Details

1. The rocket, A Bt-60, 2 stage scratch build. She has a 9'' booster, 6 inch gap stage. fully loaded its 10.7 oz. A 24mm booster to a 18 sustainer.

2. The white Bt-55 tubes hold the 2 booster chutes. On the booster there is 18'' rubber bands to attach the 10'' chutes.

3. The chutes get folded up tight and put into the white tubes, then the rubber bands get pushed in.

4. Then the booster gets attached to the short coupler. And we have a rocket!

5. On staging, The booster falls away and pulls out the chutes.

She has been flown once and It worked prefect! A D12-0 to a B6-2 makes a nice slow flight. The booster weights 3 ounces and the sustainer is 7.5 loaded. I guess it might be possible with a AT D21 for a single stage.

1. Shows the chutes falling away when it stages.
2.-4. Some more shots, last one is its first launch but the camera is dieing.

I like it! Glad you added the pictures, cause I got nothing but static when I tried to picture it in my head.

Great work !

Do you have a parachutes deployed pics?

This is one VERY cool design. You should see if Mr. Flis or another vendor here would be interested in marketing it.

Great idea. I've been trying to come up with a way to stage the Renegade D like the Renegade 2 stage was done, without breaking all the fins on the booster when it lands. This might be it. Really cool.

Thanks everyone for the comments,

I would have got another few separation pictures, but my camera officially died. It is now has all purple black and fuzzy pictures. So in a week I could get more pictures.

I think it would be amazing for a company like FlisKits has to make a rocket with these ideas. It just shows what can be done with these rather small simple rockets.
I made this to see if I could recover a booster that would otherwise come in ballistic. So no more tumble recovery!

My next rocket might be Bt-80 based, with the booster chute tubes internal instead of external.

Bonus points for originality! Nice work. Am I seeing three lauch lugs or do I need to move to tri-focals?

judo said:

Bonus points for originality! Nice work. Am I seeing three lauch lugs or do I need to move to tri-focals?

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No, that is 3 launch lugs..... I usually put 3 on all my rockets, some even have 4!:bangpan: They are McDonnell straws, good for 1/4 rods.

I like to think that 3 makes the rocket a little more stable when launching.

Thats a pretty awesome idea. Internally inside a BT80 should be pretty cool, can't wait to see how it comes out.

Deployment pictures!
1. Rocket together
2. booster stages, starts to fall away
3. Booster falling away, sustainer light and burning, chutes come out
4.Chutes inflated, sustainer goes on up
5. how the rubber bands are attaches to the booster( you can see 2 of the 4 internal vent ports.)


There is also a way to have the gases vent and have no hole in the side of the booster,
Have the internal vents into the space between the 2 booster tubes, then cut holes in the bottom centering ring so the gas vents out the back/bottom of the booster:grin:

I have a newb question. Can you explain the purpose of those vent holes? Wouldn't you need as much of the "hot gasses" as possible to hit the sustainer engine to make sure of ignition?

vigilante said:

Wouldn't you need as much of the "hot gasses" as possible to hit the sustainer engine to make sure of ignition?

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Yes! But not all the pressure. We don't want to blow the booster off before sustainer ignition.

But, with the hot gasses comes the increased pressure. By venting some of that pressure, the sustainer motor has a much longer time to ignite by what ever it is that ignites it. We're really not sure. This came up in another gap thread not all that long ago.

Once the sustainer ignites, we really don't care about the interstage pressure. The booster comes off by either pressure or drag or both.

That's actually a great question.

judo said:

Yes! But not all the pressure. We don't want to blow the booster off before sustainer ignition.

But, with the hot gasses comes the increased pressure. By venting some of that pressure, the sustainer motor has a much longer time to ignite by what ever it is that ignites it. We're really not sure. This came up in another gap thread not all that long ago.

Once the sustainer ignites, we really don't care about the interstage pressure. The booster comes off by either pressure or drag or both.

That's actually a great question.

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Also to add on to this,
You don't want all that 'cold' air in the tube, so the HOT gas pushes the colder air out though the vent holes. Then the hot gases hit the top engine and it lights, causing sooo much pressure the booster shoots/ejects/falls off!

I see. Makes sense. I'm glad I asked.

Really nifty take on recovery for the booster. Practical, yet it makes for a very creative design. Is it pretty consistant?

Yessir ,I said it before ,and I`ll say it again......VERY nice rocket and design !!

I also like the two chutes.


Paul T

foamy said:

Really nifty take on recovery for the booster. Practical, yet it makes for a very creative design. Is it pretty consistant?

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With one launch I'm not sure yet, but the first launch went good!

I'll report back when she goes again.:horse: