Abstraction

Onebadhawk
madcow rocketry
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Abstraction flew! It took off like nothing i've ever seen before. Hands down the fastest rocket at BALLS this year. However...

Apparently, these DVK fin cans do have a limit, and I , er the N6000 took it far beyond that. About a half second before burnout (keep in mind this motor is progressive and was still putting out 1500 pounds of thrust at this time) one of the fins sheared completely off and one other was highly loosened. With the sudden instability, it did a HIGH G corkscrew where the fiberglass tubing snapped right off above where the motor was supporting it. The chute and 1/4" TK shockcord promptly snapped off when the rocket decided it didn't like having them tag along anymore. The bolted on nosecone sheered off to from the G forces. It, the ARTS, and G-Wiz stowed inside were never found. Both ends of the fiberglass payload section zippered as well from the lenght of kevlar on the Fireball of which, half the foam ball is missing. After all this, the booster went stable again and continued up a litle bit and we followed the tracking smoke until it was lost visually to the clouds. About a minute later a whooshing sound was heard and sure enough about a hundred feet away <Myself and some of the AHPRA guys were standing about 200 feet from the pad to use the remote firing system <what a rush!>
we saw the booster coming in hot and it promptly coresampled destroying the motor case which is oblong on the forward end and curved all the way down.

It was disheartening to see this happen, however i'm not discouraged. I firmly believed it would have worked have the fin can held up which i should have made myself to begin with so i know exactly how strong it is, nad what it can take, and most of all making myself the only person I can blame. This is what I will do from now on as my projects get bigger and more extreme. I already have a plan for my return next year to redeem myself, making many great leaps and most of all learning from this year's bad judgement. What good is failure if you don't learn from it right?:)


BTW, look for me on the Extreme Rocketry DVD when it is released!

Pics soon, none of the flight though, too fast. I mihgt be able to get a few frames from the video that Daivd took though...
 
ouch! hate to hear about that ...obviously an expensive lesson ! I guess thats why missiles are generaly made from metal
too bad ,I was hoping for some cool pics or vids
 
Originally posted by rocwizard
Abstraction flew! It took off like nothing i've ever seen before. Hands down the fastest rocket at BALLS this year. However...

Apparently, these DVK fin cans do have a limit, and I , er the N6000 took it far beyond that. About a half second before burnout (keep in mind this motor is progressive and was still putting out 1500 pounds of thrust at this time) one of the fins sheared completely off and one other was highly loosened. With the sudden instability, it did a HIGH G corkscrew where the fiberglass tubing snapped right off above where the motor was supporting it. The chute and 1/4" TK shockcord promptly snapped off when the rocket decided it didn't like having them tag along anymore. The bolted on nosecone sheered off to from the G forces. It, the ARTS, and G-Wiz stowed inside were never found. Both ends of the fiberglass payload section zippered as well from the lenght of kevlar on the Fireball of which, half the foam ball is missing. After all this, the booster went stable again and continued up a litle bit and we followed the tracking smoke until it was lost visually to the clouds. About a minute later a whooshing sound was heard and sure enough about a hundred feet away <Myself and some of the AHPRA guys were standing about 200 feet from the pad to use the remote firing system <what a rush!>
we saw the booster coming in hot and it promptly coresampled destroying the motor case which is oblong on the forward end and curved all the way down.

It was disheartening to see this happen, however i'm not discouraged. I firmly believed it would have worked have the fin can held up which i should have made myself to begin with so i know exactly how strong it is, nad what it can take, and most of all making myself the only person I can blame. This is what I will do from now on as my projects get bigger and more extreme. I already have a plan for my return next year to redeem myself, making many great leaps and most of all learning from this year's bad judgement. What good is failure if you don't learn from it right?:)


BTW, look for me on the Extreme Rocketry DVD when it is released!

Pics soon, none of the flight though, too fast. I mihgt be able to get a few frames from the video that Daivd took though...
Click to expand...

Awful news man. Did you do a forensics on the can? I'd like to know just why it failed. I'd assumed these were one piece like Acme's.
 
Going Mach 3.5 was the cause of the failure;) It simply didn't have enough carbon cloth built into it. Les Derkovitz of NASSA also shredded a custom DVK 5" fincan on a blue O he made that was supposed to go Mach 3. Looking at the video, the flame was about 10-11 feet long when compared to the 8.5 foot long rocket. It was truckin'! Like I was saying, I have much greater plans. Mach 4+ looks like the plan for next year. I am looking to go hypersonic eventually...
 
Why not switch to aluminum fin cans?

I've seen some great ones on Jim Amos' rockets...pretty rugged things.

Edward
 
Originally posted by edwardw
Why not switch to aluminum fin cans?

I've seen some great ones on Jim Amos' rockets...pretty rugged things.

Edward
Click to expand...

I think there's a lot more exploring to be done before having to move to metal. A one piece can frinstance. From what I read, this can failed at joints. Eliminate those. Somethinng light enough able to be molded, injected or poured, that can handle the heat without weakening. We need some basic materials science going on as we grow 'em bigger.
 
Originally posted by rocwizard
Abstraction flew! It took off like nothing i've ever seen before. Hands down the fastest rocket at BALLS this year. However...

Apparently, these DVK fin cans do have a limit, and I , er the N6000 took it far beyond that.
Click to expand...

Sounds like a hell of a rocket :)

Any photos/videos?

Did you fly it on the 'L' motor at all?
 
I don't like aluminum fin cans for several reasons, 1) they're to easy to make, 2) they're are heavy, weight needs to be at a minimum for the kinds of speeds I want to reach, and a third reason which i'll reveal later.

Composites can be made to work just fine, it just needs to be done the right way. A better core material, and more carbon whould do it.

I never did fly it on the L for fear that some minor problem would arise a prevent the N flight from going off, leaving me with a huge motor and no rocket to fly it in. After consulting with with, who advised me similarly, I did just so. I don't regret the decision one bit.:)
 
I can understand that. I just like them cause they are pretty strong. Also, another thing that I notice that Jim does a lot is all aluminum rockets. Pretty spiffy things. I know he flew Colo-RAD-O to 45K at Balls, what a flight!

Edward
 
Um....


Any pics at all?


Cool, even though it sheared the fins this was an awesome project, Hope you can make it to M5 :D

So, with the altimeters gone, you are still saying mach3?


Good luck with next year's project!
 
When Eric flew, I was standing next to Jeff Taylor, Neil McGilvray, Rob Bazinet, and Darren Wright, who was prepping a very similar rocket. They counted down and the rocket took off so fast that even from 1500 feet Jeff and I had trouble following it in binoculars. As soon as it shredded, Darren exclaimed, "All right, that's it, I'm not flying!" Those fin cans need work ;)

My dad was pretty close to the pad and got some awesome footage. I'll have video posted in the next day. In the meantime, frame grabs will have to suffice.

Here's the best liftoff shot I got... check out the flame. I love the high aluminum propellant :D
 
Hard luck! It's not the fin can's fault. I think you guys just found the speed of FWF.
 
I think this year's BALLS should have been subtitled "Death to all fin cans."

Many (all?) of the rockets constructed using composite fin cans failed.
 
If I were to buy a fin can again, it would definitely be from Dave Triano of Shadow Composites.

But seriously Jeff, I think you're right, every commercially made fin can rocket that flew was shredded. It happened to me once now, it won't happen a second time!;)


My plan for next year starkly contrasts that of this year. If anything is going to fail, it's not going to be the fins:):D
 
here are some pics finally...


I needed a wee bit of help getting the looong motor put together:D
 
We are GO for launch...


I was a bit tense at the moment if you didn't notice:kill:
 
wow ..... that is awesome.....


what happened to the abck of the case?
 
The motor was running just a little too hot. It was just about to let go, and blow the nozzle, but the motor shut down just in time. What can I say, a Frank load in a Paul case, I guess it was bound to happen:kill:

With some stronger housing, it'll work again just fine.
 
Originally posted by rocwizard
If I were to buy a fin can again, it would definitely be from Dave Triano of Shadow Composites.
Click to expand...

Are those custom? I didn't see any on the site.
 
I didn't mean to imply that I actually will buy another fin can, despite the manufacturer. I just meant that Shadow Composites is the only company I'd trust to make me one. Yes it would have to be custom, and yes, it would surely cost an arm and a leg.
 
that is a kosdon case???.....or at least it is anodized that way.
 
Originally posted by DynaSoar
Are those custom? I didn't see any on the site.
Click to expand...
Yes, that would be a custom part. Dave can make anything as long as the check clears.
 

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