Dual stage Armageddon...

[pr_rocket04]

I am in the process of building a 4" Armageddon that has a 75mm mount, and decided I'm going to go for a 2-stage. I'm going to get a 5.5" Armageddon kit and use the parts to make the booster, which will have a 98mm mount instead of a 75mm. I have already simmed a rough idea and I have an idea of the proper booster length.

I was wondering if you guys could send me in the right direction as to how I need to mount my motor in the sustainer, and where I could get the right size transition? I've never done a 2-stage like this so I don't know how these two join together. I know about the electronics and such.

 

[PunkRocketScience]

WOW! What a cool idea! Can you post the rocksim file? And pics when you have them?

 

[pr_rocket04]

Here you have it, but beware, this is very rough, notice I have just thrown some mass units in to get in the range of my projected weights(and weighted the nose a bit), and a lot of small things aren't accounted for(I was in a hurry). I once thought of adding 4 outboard 38mm's to ignite with the 98mm (Gates Brothers anyone?), but then came to the conclusion this would just be another time barrier, so I discarded that idea.

I plan to carbon the entire rocket. The booster will also have dual recovery using a single compartment, with the help of a Defy G Tether. The rocket will have dual GPS recovery via my laptop, and I'm waiting on VPS to build me a video system(and they're lagging), which they claim will transmit from the projected 20,000+ft. Just everyone realize this is extremely costly for me to follow through with, so I cannot say how soon it will be completed, as my project 300zx TT comes first right now.

Feel free to work on the design for me and post what you have come up with. Call me dumb, but I couldn't load a chute into the booster, can anyone add to that?

Once again my problem area is in the transition, I don't know how the motor mount needs to be set up on the sustainer to comply with the booster section.

 

[pr_rocket04]

So can anyone familiar with two stage rockets tell me what I need to do?

 

[pr_rocket04]

Alright, so no one knows how to attach the booster to the upper stage? Does anyone in here do dual staging? Someone has to know this, please!!!

 

[Justin Horne]

Well, here's what I know. A person at my club is building a 2 stager that should reach 60,000, so im sure this will work for you. First, he took a coupler tube that fits the booster tube. Then, he took plywood "ribs" that he glued to the inside of the coupler. The ribs go straight up put or coupler, turn in (to form a transition) then stop. At the top their inside diameter is the same as the OD of the sustainer. He then put a centering ring and a stop inside the coupler. this keeps the sustainer straight and secured. After that he wrapped it with same light wood, and glassed. Hope this helps.
Justin

 

[jetra2]

If you're doing a relatively low-power staging, you can use a straight coupler for the, well, coupler. Other people seem to prefer metal tubes in the upper stage and metal rods in the lower to connect it. If you use four rods/tubes, you will get a lot of stability. Make sure that there is a bulkhead at the end of the booster so that you won't run into problems with the upper stage motor charring the interior of the booster as it ignites, and coat everything that'll be exposed on the interior with a thin layer of epoxy to further protect from charring, especially on paper tubing.

Jason

 

[DumasBro2]

I redid the coupler on my Terrier/Sandhawk this spring from the shafts method to a coupler. I laid up a coupler starting from the inside as follows: one wrap of 3.4 oz. glass, two wraps of Kevlar®, two wraps of 6 oz. HS carbon fiber, two wraps of 6 oz. glass followed bay a final wrap of 3.4 oz. glass. This makes for an extremely light and a very strong coupler.

Steve