It's either going to be a big success or...

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gpoehlein

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Well, I decided to push cardstock model rocketry to its upper limits. I wanted to see just how large I could make a rocket out of cardstock and still launch it with an Estes E9. The result: a 4" diameter Red Max upscale!

Here are the parts ready for assembly:
 

gpoehlein

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Here's the fin can. Those fins are made from two layers of cardboard with crossed grain for strength, covered by two pages of 110# cardstock printed on my Epson printer.
 

gpoehlein

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And here is the assembled rocket, ready for its chutes and nose weight. Rocksim says it will get about 300 feet on an E9, but I will weigh it and run the actual numbers through Rocksim before actually launching it. This thing is bigger than I expected, that's a standard Alpha sitting next to it for scale.

Like the title says, it's going to be a spectacular success or... ;)

Greg
 

lalligood

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SWEET! :cool: :D Good luck too!

I'm sure there's going to be a lot of people who'll be scratching their heads over you building a rocket that large out of paper (cardstock), but I say just refer them to the FlisKits' Midnight Express... When laid flat, paper indeed has little strength but it becomes suprisingly rigid & strong when formed into certain shapes.

You just never know if it's gonna work...but it never hurts to try!

BTW, I can tell you've already invested a lot of time into building this one, but what about building an all white version to test. No point in abusing your masterpiece without (potentially) sacrificing your work... ;)

Way to push the envelope :D
 

rstaff3

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Looks great! The large diameter should help. Can you share the details of the fins/rings? One layer of cardstaock, 2, 3...?

Well, best of luck. Can't wait for the flight report.

PS Wish I had thought of this idea ;)
 

Micromeister

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Great Idea Greg:
I see no reason to stop there, next cluster a 4" Goblin or other should fly just fine. Landings may prove more of a recovery challange;)
 

gpoehlein

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Well, the cardboard I am using is something like a thin brown bristol board - it is about .053" thick. The fins are made from two layers each of the cardboard and 110# cardstock (which is about .005" thick). So each fin is about .116" thick.

The centering rings (there are 6) are one of the keys of the design - they are what keeps the outer skin round. They are made from one layer of cardboard and one layer of cardstock - thickness about .058".

The rocket has a .96" diameter stuffer tube running nearly the length of the rocket, and the fins go through the outer skin and are also glued to the stuffer tube - so the rocket is, in reality, like a 1" diameter rocket with a 4" skin wrapped around it - the outer skin does little for the rocket's longitudinal strength.

The nose cone is one cone, two transitions and one cylinder. There is a 1/2" foam core disk in the base of the shoulder.

I plan to put two 12" parachutes in the rocket for recovery. There is a 3-1/2" chute compartment above the stuffer tube. I didn't have any kevlar cord, so I used four strands of cotton thread for the shock cord. I cut a hole in the top centering ring and looped the string around the stuffer tube - that sucker ain't going anywhere!

All in all, I figure there are about 18 or 19 pages of printed cardstock that went into it. The forward and aft body tube sections take two pages each.

Now all I have to do is figure out what to launch it with ;)

Attached is a pdf file outlining the dimensions and positions of the parts.

Greg
 

Ryan S.

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I really have a feeling that will go higher than 300 feet, what does it weigh? I am guessing close to nothing
 

Justin Horne

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But at the same time, weighing so little, it will slow dows really fast.. I think...
 

lalligood

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Originally posted by Justin Horne
But at the same time, weighing so little, it will slow dows really fast.. I think...
You're right...not to mention that there is a greater drag from the large diameter (surface area).
 

rstaff3

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Given the relatively thick fins, the diameter, the stuffer tube, etc. this sounds like it has a very high chance of success :)
 

bsexton

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This is similar in concept and execution to the paper V2 highlighted in Sport Rocketry a few issues ago. Great idea and good job! I think it will fly well and I would also have to believe it will go higher than 300'.
 

slim_t

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Just wanted to say this looks incredible Greg.
Thanks for linking from the other thread or I would have missed it.
Good luck with the flight. I believe it will be a great success.

One question, is the stuffer tube also rolled from card stock?

Tim
 

GL-P

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That's awesome! Landings might be interesting! Looks great!
 

gpoehlein

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Originally posted by slim_t
Just wanted to say this looks incredible Greg.
Thanks for linking from the other thread or I would have missed it.
Good luck with the flight. I believe it will be a great success.

One question, is the stuffer tube also rolled from card stock?

Tim
Yup - the whole rocket is cardstock from the nosecone to the stuffer tube. The fins are two layers of cardboard covered with cardstock. Now I just have to put the launch lugs on and the recovery system in and she's ready to fly - hopefully in a couple of weeks (gotta go to a gaming convention next week, and the preparations are time consuming!)

Greg
 

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