Un-Fluttering a Flutter-By...

[Screaminhelo]

One thing that I learned when I upscaled the Flutter-By was that introducing a slight angle to the fins of the upper section caused a gentle spiral during recovery that kept it closer to the pad. It is a simple rocket and the best way to get the whole thing back is to keep it reasonably low.

By the way Top- a carbon fiber Flutter-By? You are a mad genious!

 

[TopRamen]

The original post was more concerned with losing the parts. Streamers could be attached to both parts, they don't have to stay together, a colorful streamer might make the parts easier to find in tall grass.

Good point!
I get carried away lately in twenty different directions, and ramble on or go off topic frequently.

I'm going to connect the two sections with either 70, 100, or 150# Kevlar and make it long enough that hopefully it works out okay.
I'm going to see if I can wind that Kevlar cord around some sort of spool in the middle of it's length, so that as it comes apart, drag and instability have an instant to slow the pieces and then the spool portion will soak up the rest of the energy as it unwinds.
That's all I got, nothing fancy, but we'll just try it and see what happens.
I'm thinking as much Kevlar as I can fit into what is left of the nose cone after adding some epoxy, weight and an eye bolt.
The clay that came with the kit I have weighs 7g. on the nose, but I did not weight the components until after I had mucked about with them, and since it is such an odd design, I can't say I have any idea how to mindsim it, so I'll likely have to rely entirely on Openrocket this time to feel confident about launching it.
We'll start with small motors, but to ensure adequate off the rail stability I'll make a point of only flying it from the 1500mm Makerbeam.

 

[Screaminhelo]

I used a bamboo skewer though the launch lug to balance my upscale.

 

[TopRamen]

I used a bamboo skewer though the launch lug to balance my upscale.

I remember that thread. https://www.rocketryforum.com/showthread.php?119972-Is-this-crazy-for-my-first-scratch-build

Have you flown it?

The design scares the heck out of me!
Just because I don't sim everything does not mean I'm not a stability and zero-twist nazi!
Down scale maybe, the scale it is at, yeah, no problem, but upscale?!!!:y:

I'll fly the thing I'm building, but unless it flies like and Angel, I will likely not revisit it in any scale.

 

[Screaminhelo]

I have flew.the up scale four times until top section ended up in a tree. Granted, the size allowed me a little more wiggle room but my gut feeling is that the combination of short and stubby with barn doors for fins makes the basic form very stable to begin with. With an E motor, OR gave me less than .5 cal stability but it was a dream when I did a swing test. When it gets re-built, I am going to swing it with no weight and sneak up to enough.

I built it to separate like the original and a slight, unintentional cant on the upper fins recovered that section much like a maple seed. I will definitely replicate that and add a streamer to the booster as lt did drift a ways on the way down but not so far to make that big red chunk hard to find.

My son and I really enjoy the design and I am really digging your "over built" take on it.

 

[TopRamen]

Thanks.

It will be a real hoot for me too when I launch it for the first time, as it is totally a learning experience, and not my typical type of rocket.
I'm only keeping things interesting for myself, but if others get a kick out of it, or they expound on my methods and come up with something that
someday saves lives or something, then atleast i've played my tiny part.
I was recently pondering Airbags for Airplanes, that used Super Thin CA and Carbon Fiber for near instant repairs.
Sure, Epoxy is the preferred method, but what if you are a victim of Time???
More than a few military Jets have returned to Base with more than half a wing missing, thanks to the skills of the pilot and the intelligent design of the Aircraft itself, but what if they could continue fighting instead of RTB?

We have to dream up solutions to problems whether or not we as individuals are in any position to implement or design them with the appropriate materials and research.

I always keep some of those wire ties for trash bags in my wallet.
Once, in Habiniyah, Iraq, one of our vehicles ended up in an impact crater and they were fine, but they slammed the throttle cable so hard they broke it at the point where it flexes the most.
I ran into the situation and fixed it with something most folks use everyday to keep their Bread fresh.
I had to tell them what gear range to use to get out of the crater, but we were all able to continue movement.
It's that "For want of a Nail" thing.

https://en.wikipedia.org/wiki/For_Want_of_a_Nail



Everyone else was worried about towing it out, but it was just a tiny piece of wire, and I did not want to wait around.

 

[cavecentral]

Carbon flutter by should be interesting. Flutter By Night?

 

[Screaminhelo]

I think that CA is a great resin to use for small pieces, it is strong enough for the application and pretty easy to.work with (I have effected many non-structural temp composite repairs on aircraft over the years with CA). I'll work on getting a reference for you for when you start to go big enough that epoxy makes sense to use. It will have much more information that you will need but methinks that you will find it interesting nontheless.

 

[TopRamen]

Carbon flutter by should be interesting. Flutter By Night?

That is a good one.
I was thinking Fiber By, but that sounds stupid, so "Flutter By Night" it is.

It's too bad I don't have time for a build thread, and I hate hijacking this one, but if it gets questions answered for the OP, then it's not the worst thread hijack ever, only a close third.:wink:

The tubes are still light, as I relieved them of their glassine layer before the CF, and unlike Epoxy, CA adds only as much weight as is necessary to lock up the fiber matrix.
I actually did a few everyday use Items with CF and CA, and will share my results after a couple of months of use, as I too was thinking that it was a silly idea til' I tried it. There are many types of CA, and some have polyesters or rubberized stuff in them that adds durability, so just knocking it without trying it just because "The Aerospace industry does not use CA on Composites..." is the silly thing.
Maybe they should. Can you imagine airbags in the fuselages/wings of Jets, both military and civilian, that were made of CF/FG, and they not only filled instantly when a holes was created but were locked instantly with an aerosolized CA compound developed specifically for that purpose???





The fins are not done yet, but they are 1 layer of 2.3oz Thayercraft glasscloth that I think I actually got from you Kevin, sandwiched between the black paper, and they will get the CF layer done with ZAP Z-Poxy 30 minute, and be pressed on my granite slab, which I treat like a surface plate, under 120 lbs. of weights, and let to cure for two days, one side at a time, on West Systems Release Fabric, so I don't have to do a bunch of sanding afterwards.

 

[TopRamen]

I think that CA is a great resin to use for small pieces, it is strong enough for the application and pretty easy to.work with (I have effected many non-structural temp composite repairs on aircraft over the years with CA). I'll work on getting a reference for you for when you start to go big enough that epoxy makes sense to use. It will have much more information that you will need but methinks that you will find it interesting nontheless.

I use Epoxy on lots of layups, and research it as part of my daily "Things To Research Today" List of things to do.
I've been working with composite in the normal way for about two years or more now, and have glassed up to 2.6" tubes, done Tip to Tip and Tail Cones and if you've seen my ongoing SA-5 Gammon, you will see me using Epoxy exclusively on all fiberglass structures.
Please, don't bother with any kind of reference or taking time to do anything to go out of your way, as I'm quite familiar by now with lightweight glassing, and have no plans to advance to any heavier tech just yet, though I have a couple of years of research in that regard too.
I don't build ANYTHING that does not have atleast some form of composite construction tech.

This is the insides of the Booster Section for my SA-3 small scale, and it too is about to face the glass and epoxy tomorrow morning.
It only took me about an hour to knock this mock up out with foam and such, and over the coarse of the day has become a viable build.
The SA-5 project has forced me to come up with lots of new ways to make things light and strong, and the best way to do that is with composites, not balsa and cardboard.

 

[Screaminhelo]

You know, I had forgotten about the SA-5 and all the gassing that you had been doing leading up to it.

As for CA in aircraft structures, my taken is that is is generally too brittle, even the stiffest of composite components must have a flexible nature to it so that it is not destroyed in normal use. As for self healing composites, they are playing with the idea, a similar concept to self sealing fuel tanks.

As.for the reference, it is just a matter of sending a PDF when I get back to work this week, I juse hAve to confirm the stats of the manual. If you are ever interested, give me a shout. It outlines vacuum schedules and some techniques that may help with achieving a smooth finish and a couple of ways to work with complex shapes just to name a few.

 

[TopRamen]

You know, I had forgotten about the SA-5 and all the gassing that you had been doing leading up to it.

As for CA in aircraft structures, my taken is that is is generally too brittle, even the stiffest of composite components must have a flexible nature to it so that it is not destroyed in normal use. As for self healing composites, they are playing with the idea, a similar concept to self sealing fuel tanks.

As.for the reference, it is just a matter of sending a PDF when I get back to work this week, I juse hAve to confirm the stats of the manual. If you are ever interested, give me a shout. It outlines vacuum schedules and some techniques that may help with achieving a smooth finish and a couple of ways to work with complex shapes just to name a few.

I do appreciate that. I have been given a lot of stuff like CD's with PDF format books and manuals about composite construction techniques and even the vacuum process, but most are more advanced then I will ever need.
I am definitely interested however in creating "Complex Shapes", so yes, consider me interested, but don't go out of your way, and Thank You.