@Dotini did something like this.Has anyone done this? I bet someone has done this. Boattails move one's CP forward. Ringtails are quite effective at moving one's CP aft. When a boattail is placed inside a ringtail, which one wins?
View attachment 464060
The ring's pylons are visible in the bottom view. If it helps, the pylons could be extended forward to fill the boattail's profile up to the bottom of the body tube, but I bet that wouldn't help much if at all.
Looking at it, I see that it's similar to some air dropped bombs, and also to some torpedoes. But torpedoes can have guidance systems (the modern ones all do, if I'm not mistaken) and the bombs only have to be nominally stable.
Of course I could, and will, try it out in RS, and maybe OR too. (Wait, are ringtails that feature that OR lacks until the next release that's been just around the corner for a couple of years, or are ringtails available today?) I'm just not sure how far to trust the simulations for a model that's rather far, but not terrifically far into the weirdness zone.
If this works, it just begs to be tube launched. Before I spend the time to do the research, does anyone happen to know of a standard BT size (OD) and a common pipe size (ID) that are a good match for the purpose (close but not tight)? Don't trouble yourself looking, as looking is my job unless someone already knows.
you mean...Has anyone done this? I bet someone has done this.
If this works, it just begs to be tube launched.
Dotini also did this, Animist II, big brother to the Animist seen above.@Dotini did something like this.
see post 47
View attachment 464232I'm extremely embarrassed to report that due to my age (72) and Paleolithic nature, I do not possess the technology to take and send a picture. I've asked my fellow Boeing retiree Blair, a knowledgeable engineer and close friend, to teach me how to send pictures. I'm going to do this thing...www.rocketryforum.com
No, I mean what I sketched in post 141. The ring is the same size as the airframe (unlike Dotani's) and there is no stand-off pushing the ring back.you mean...
Again, nice look.Dotini also did this, Animist II, big brother to the Animist seen above.
View attachment 464762View attachment 464761
I can add that it is very sturdy and can take a rough landing. It goes very high, does not weathercock, and seems to be a natural backslider.
I suppose if someone wanted to tube launch it (but why?), they could add a canard ring or canard fins to center it in a tube.
Yes, agreed on all points. Animist II backslid on a flight in which the streamer failed to deploy properly (I had left the rubber band on it). I've noticed this on other flights with proper deployment as well. IMHO, there is a lot to be said for models which land reliably without loss or damage, and do it over and over again. In only a short time, I will reveal my new pseudo backslider which will try to live up to that particular set of virtues.Again, nice look.
did this actually BackSlide with nose in place? I have seen many streamer and parachute rockets that have what I call a “Pseudo-BackSlide”. (Which may not the that “Pseudo”). Basically the deployed the nose and chute or streamer, nose came down hanging on the chute or streamer, the body of the rocket (still attached to nose and streamer) turned horizontal tail first with very slow tail first trajectory parallel to horizon will it fell, maybe better out, it descended attached to but parallel with the nose cone and chute, so it wasn’t “dangling” from the chute, in a horizontal orientation, and seemed to have a minimal added “backward” trajectory.
this seemed to happen more with my asymmetric fin rockets. I am pretty sure that asymmetric fin rockets need more fin area to be upward flight stable. They are not very efficient, I am sure I sacrifice some altitude, but good enough for government work or sport flying, and I think on my few flights with spectators they get a few more ooohs and aaahs (due to corkscrew smoke trail) than more classic and efficient 3FNC low and mid power rockets.
I was thinking, “Fish in the water!”
Who do you order those desirable Estes parts from?I just ordered parts to make a quick and easy prototype. Bit Bertha nose cone and V2 boat tail with a BT-20 core hole. NYPower is a week away, and I just might have it ready to fly (built and swing tested) by then. It'll probably have to have launch lugs this time. (If I can't get a proper pipe size, I could use FARGs, but I don't expect I could get those ready by next weekend.)
Correction: Ordered the Apogee FARG for it.
Already been done. See attachment. One of the best flyers I've ever built.I do indeed. Id' be happy if this thread becomes like that one, sims not required.
Well, this one's even less than half baked. And actually it's two. Y'know the design with a ringtail internally tangent to the body tube? Or a single tube fin attached on the opposite side from it's centerline, if you'd rather call it that. What about applying two of those rings, with interlocking slots where they pass each other? That'd look nifty, wouldn't it?
View attachment 394764
And what about one of these tangent ringtails but with the ring actually a Möbius strip? Oh, sure, the twisting of the ring would certainly play hob with its aerodynamics. That's OK, fix that by making the arrangement symmetrical by using two like the picture above. (Yeah, I did say "less than half baked".)
Come on, somebody else!
Careful. Internally tangent rings are dangerously close to tube fins. And you shun tube fins.Ooh, you built that one? I'd love to see some pics, and also hear how you did the paint sequence. It's a beautiful design, looks like the sort of thing I would design only a lot better.
I have created a number of designs with interlocked rings like that. Regrettably none of them are as nice as that one.That's a beautiful design. I may need to add that to my virtual build pile. (Since the pile is virtual, it doesn't matter if no kit exists.)
Careful. Internally tangent rings are dangerously close to tube fins. And you shun tube fins.
One method of using Gas Dynamic Stabilization. I'm working on a Polaris A3 missile that using an alternate method...you mean...
I didn't want to hijack the other thread. This is the build sequence for a finless rocket I designed and built last August. Hopefully I'll get to fly it before this August. One main difference is that it's designed to be tube launched, rather than off a rod/rail. I've got a nice 4' heavy...www.rocketryforum.com
I'm amazed you don't remember posting to this thread! But please, put your own spin on it! I'd love to see what you can do!
Here is a pic painted, no decals yet. The flight this weekend had a chute malfunction and a hard landing. One of the long stringers on the one fin cracked (reparable). If I were making it again, I would use basswood for the stringers....Ooh, you built that one? I'd love to see some pics, and also hear how you did the paint sequence. It's a beautiful design, looks like the sort of thing I would design only a lot better.
GDS is certainly cool, but not what I'm trying for. The point isn't just to go finless, it's to test the specific idea of a ring tail and boat tail that overlap. Anything else, while all well and good, is off the mark.One method of using Gas Dynamic Stabilization. I'm working on a Polaris A3 missile that using an alternate method...