ROCStock 37. Lucerne California

[bandman444]

Bryce, I've got HD video of your Mega Mean Machine flight (ouch). Let me know if you want the link. Here is how she looked before flight with contrasting mini-me.

-Mike

<img src="https://www.rocketryforum.com/attachment.php?attachmentid=133663"/>

Shoot me a Pm and I will include it in my massive writeup. (Still waiting for a couple good video to come live) or you could leak it here first.


Ouch is right.

 

[gdjsky01]

I want video!!

 

[Wayco]

Not quite video Jeff, but I got a few shots of this amazingly agile rocket:

I think we need a bigger launch rail....

Don't ask how that speck got on my lens, but as you can see the big meanie was already showing us how flexible it was:

A little wiggle to the left....

A big wiggle to the right:

Back to the left:

Now for the real trick stuff:

Bet you never seen a rocket fly backwards, still climbing:

Still climbing:

Yep, still climbing. I got a total of six shots like this:

Almost done with the up part:

Now let me show you my next trick:

We don't need no stinkin' chute:

If you were a 28 ft. rocket where would you want to land:

Right about here will be just fine:

With two cameras and three days at this launch, that is the only flight I got a picture of.

 

[bandman444]

Here's the video as mentioned above.


https://vimeo.com/68383682

 

[rdbones]

Sorry to hear / see that, It was a nice looking rocket.

I think you have, however, inspired us to make a bigger one!

 

[gdjsky01]

What was the airframe? Maybe blue tube or magnaframe?
Posted at 30k or so over Texas.

 

[bandman444]

Sorry to hear / see that, It was a nice looking rocket.

I think you have, however, inspired us to make a bigger one!

Haha. Thank you.

What puzzles me is the flip it does at the end of the burn? I guess because it was so stable that it over corrected and flipped end over end. Really bizarre.

The parachute not deploying was an different issue although it does seem to have gotten tangled preventing the chute from being pulled out of the tube.

 

[bandman444]

What was the airframe? Maybe blue tube or magnaframe?
Posted at 30k or so over Texas.

All Blue Tube 2.0.

 

[rdbones]

I dont know - I was wondering the same thing - Hard to tell in the video.

Still waiting for your flight report on the 2 stage,
and the other flights

 

[CarVac]

Haha. Thank you.

What puzzles me is the flip it does at the end of the burn? I guess because it was so stable that it over corrected and flipped end over end. Really bizarre.

The parachute not deploying was an different issue although it does seem to have gotten tangled preventing the chute from being pulled out of the tube.

My suspicion is that being such a long rocket, the critical angle of attack before the rocket becomes unstable is fairly small. With the airframe flexing back and forth like that, the rocket reached that threshold and then flipped around. Once backwards, it keeps "gliding" upwards with a moderate angle of attack (but backwards, of course). That's a recovery method used for superrocs, apparently; there's a paper somewhere explaining it.

I don't know offhand the details of your build, but for the couplers, which are 12" long (I presume; only true if you bought separate ones) should have only about 2" glued in, leaving a full 10" remaining to slide into the next part of the airframe, for maximum stiffness. Good epoxies are much, much stronger than needed for the bonds between couplers and airframes, so long as you butter them up well, so be generous with the protruding portion.

 

[jeffgeraci]

Hey Bryce, I can't believe I missed that launch!! But I did get to see the successful one you did on a K590.

Notice how the weakest side of the airframe (left) bent immediately after takeoff. When it reaches maximum tension, that stored energy forces the frame to bend in the opposite direction (right) since the motor is still thrusting- and that's why the nose changes direction before the aft section. Note that the motor burns out right at that moment. The inertia keeps the fin can traveling in the same direction, so I'm guessing the fin can has some weight to it, relative to the majority of the airframe?? If not, then I'm completely wrong.

I'm most interested in the initial bend. Unless you had wind coming from the left of the video, I would say the initial bend occurred on the weakest vertice of the airframe, due to an excess of initial thrust. I would say sorry for your "loss", but hell, I've only landed 5% of my big birds. Atleast you don't have to worry about transporting them back home and then finding a place to store them.

Are you going to balls in Nevada in Sept? I am, and looking for folks to carpool with. Let me know.

 

[KenRico]

Stuck the landing !

Good times !



Kenny