Black Brant launch 5/7/21

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Yeah. I was just pondering an idea about flip out fins. It would look mostly scale while on the ground, and the fins would pop out before staging so it would be stable at altitude. Just something to get the 4-stage effect.

View attachment 463943

That's really the simplest way to go. It won't be scale during 4th stage flight, but the extra fiddling and controls necessary to maintain it finless are not negligible.

May actually be a decent use for one of the BPS space motor gimbles
 
Maybe you could let the third stage coast until it's going slowly enough for a TVC system like BPS's to work. Then it's an off the shelf solution and still scale.

On the other hand, one advantage to doing it with reaction wheels would be that they can help keep you vertical during the whole ascent, all four stages.
 
I've yet to see a viable application of reaction wheels in a model or highpower rocket. Would love to be proven wrong there
Joe (BPS.space) worked with them on a few of his rockets. He was using it to cancel spin if I remember correctly.

If you're already set up for a 4th stage, just have your 3rd stage induce spin and then your 4th stage shouldn't need fins of any decent size. You'll start to tumble as your velocity drops but you should already be high enough at that point that atmosphere is less of a concern.
 
Joe (BPS.space) worked with them on a few of his rockets. He was using it to cancel spin if I remember correctly.

That's news to me, which vehicle was it?

If you're already set up for a 4th stage, just have your 3rd stage induce spin and then your 4th stage shouldn't need fins of any decent size.

I can't recall the minimum rotation necessary to maintain finless stability.
 
That's news to me, which vehicle was it?
I think it was the later videos of his Sprint rocket. He was using his TVC to launch to altitude and then tilt to an angle mid flight and needed to cancel spin/roll to do the tilt correctly. He used a 3D printed reaction wheel in at least 2 of those launches.
 
[Y]ou should already be high enough at that point that atmosphere is less of a concern.
:eek:
Not if I ever do this! I'm talking about somewhere from 1:24 to 1:12 scale, with LP motors for little guys like BB I and BB II, and L1 motors for Talos, Terrier, BB V, Orion, etc. I'm not getting up into thin air.

(Of course, if I were to take on reaction wheel stabilization [but realistically I won't] then I'd need more volume and that stuff will weigh a bunch, so I'd probably have to move up in motor size some, maybe L2 at the high end and MP for the little guys. And MP for the little guys means upscaling the whole fleet to - 1:8 maybe?)
 
:eek:
Not if I ever do this! I'm talking about somewhere from 1:24 to 1:12 scale, with LP motors for little guys like BB I and BB II, and L1 motors for Talos, Terrier, BB V, Orion, etc. I'm not getting up into thin air.

(Of course, if I were to take on reaction wheel stabilization [but realistically I won't] then I'd need more volume and that stuff will weigh a bunch, so I'd probably have to move up in motor size some, maybe L2 at the high end and MP for the little guys. And MP for the little guys means upscaling the whole fleet to - 1:8 maybe?)
Chicken!!

LOC has a good 4" BB X kit with 54mm MMT. Add in a 5.5" Terrier with a 98mm MMT and a 8" Talos with a 150mm MMT and you could be doing the BB V to Nihka staging up above 50k (note, I wont be doing this.....its just plain silly)
 
Do you mean a 4" BB V? ''Cause BB X has the Talos and Terrier. A 4" BB V would be 1:4.33, and about 6'2" tall. That's no so bad really, but a BB XII at that scale would be 11'4", which is getting to be a bit much for my taste. Or is it?... 🤔
 
BB X is the Terrier -> BBV -> Nihka. The BB XII adds the Talos.

https://en.wikipedia.org/wiki/Black_Brant_(rocket)
LOC sells a 2.2" BB X upper stage as a single stage kit and a 3" Terrier booster as a kit.

https://locprecision.com/product/ybbx2/https://locprecision.com/product/terrier-booster/
Their 3" and 4" kits they list as BB X are only the BB V and Nihka upper stages though (not as 2 stages, as a single stage rocket). You could add the Terrier to the 3" or 4" kits to make them true BB X. The Talos booster is only on the BB XI and BB XII The LOC 3" BB X kit would be a good option to add a scratch 4" Terrier to. That'd make it 10-ish foot (3' Terrier and 7'5" BB X) which is do-able

https://locprecision.com/product/black-brant-x/
 
BB X is the Terrier -> BBV -> Nihka. The BB XII adds the Talos.
Yes, I stand corrected. I was thinking of BB XI, though Wikipedia list that as Talos-Taurus-BB V. But I think the Taurus there is an error and should be Terrier.

(The text section above the list of types states "[T]he current versions are the XI and XII, consisting of Black Brant V used as an upper stage, with Talos and Terrier boosters as lower stages". But the versions section has Terrier for XII and Taurus for XI. One or the other is wrong, and with the use of the Terrier in the IX and X as well as XII, I've gotta suspect that Terrier is right for the XI. If I were sure, I'd fix Wikipedia, but I'm not.)
 
Yes, I stand corrected. I was thinking of BB XI, though Wikipedia list that as Talos-Taurus-BB V. But I think the Taurus there is an error and should be Terrier.

(The text section above the list of types states "[T]he current versions are the XI and XII, consisting of Black Brant V used as an upper stage, with Talos and Terrier boosters as lower stages". But the versions section has Terrier for XII and Taurus for XI. One or the other is wrong, and with the use of the Terrier in the IX and X as well as XII, I've gotta suspect that Terrier is right for the XI. If I were sure, I'd fix Wikipedia, but I'm not.)
The XI and initial XII did use a Taurus booster but then they switched to the Terrier booster. Here is the blurb for that:
Black Brant XII (a.k.a. Talos Terrier Black Brant Nihka), a four-stage rocket with a Mk 11 Mod 5 Talos booster first stage, Terrier booster second stage (pre 2013 Taurus booster motors were used), Black Brant V third stage and Nihka fourth stage,[38] Black Brant XIIA

Peter Alway's RotW lists it as the Taurus for the XI and XII but I think that's because it was published about the time they switched to the Terrier.
 
It's on the pad. Sky looks overcast at Wallops, but there was also concern about clear skies at Bermuda. Will it go?
 
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