max number of stages?

[wwattles]

What is the max number of stages that you've seen?

And how were they staged? I'm thinking if you start with a couple 24mm's, then down to a couple 18mm's, and finishing with a 13mm, you could easily get 5 stages without going into the stratosphere...

WW

 

[Karl]

Ive seen a Commanche 9 stage
-Karl

 

[loopy]

Originally posted by wwattles
What is the max number of stages that you've seen?

And how were they staged? I'm thinking if you start with a couple 24mm's, then down to a couple 18mm's, and finishing with a 13mm, you could easily get 5 stages without going into the stratosphere...

WW

If you're just doing single engine direct staging, you can get a few. Just make sure you don't get too much weight. Cluster the first stage, and you'll be fine up to 6, I'd think.

 

[cydermaster]

Originally posted by Karl
Ive seen a Commanche 9 stage
-Karl

This got mentioned in this thread. There was a vid posted too. The vid was only of the take off, and then stayed looking at the pad, but you could hear the spectators count up to 9 as each stage ignited.

 

[vjp]

Originally posted by cydermaster
This got mentioned in this thread. There was a vid posted too. The vid was only of the take off, and then stayed looking at the pad, but you could hear the spectators count up to 9 as each stage ignited.

I remember that thread now - I temporarily posted the MPG up at https://members.verizon.net/vpearman/comanche9.mpg

...I just put it back up there, in case anyone reading this wants to have a look.

 

[shinbone]

Here's a picture of the Thallia, a rack rocket consisting of eight stages, all A10s. As you can see, the rocket is mostly rocket engines, except for an enclosing rack of aluminum-tape covered balsa. Each engine successively fires, ejecting the previous booster. It was launched at the Pittsburgh Space Command annual picnic last August. Although an eight-stage rack was thought to be a record, it was said that someone had done an 11-stage rack. The eight-motor rocket flew perfectly and was even recovered; no word on the 11-stager.

 

[crashinj]

So like how do you build one of these " new fangled things"?????

Looks interesting what I can see of it.

CrashinJ

 

[wwattles]

Even if this isn't how they made it, I'm pondering the concept:
Make a spring-loaded system that pushes the motors down the tube like a shotgun tube. When one burns out and the ejection fires, it ignites the next one and ejects itself out. The newly ignited one is shoved to the rear of the rocket by the spring!

WW

 

[crashinj]

Wouldn't the changing weight throw balance off as it is ejected. Maybe not, tho, come to think of it you have to do something with the dead burnt out motor. Hmmm, This is something to ponder tomorrow at work! hehe We know where my mind is going to be.

CrashinJ

 

[solrules]

Although I have not done any staging past the estes mongoose (*shudder*), I have seen some 4 or 5 stagers. The key is to keep the rocket pointed up I've seen a scratch be horizontal at the third stage (from wind, launch rod, etc) then the fourth lit...pointing down.....then the fifth....into the ground. Not a pretty sight.

 

[marvSRG]

Yeah...not only do I love BP clusters (see avatar), but I like BP stagers. I designed a rocket that my friend, Chris, built. And it was a D-C-C-C rack rocket with a drop away D booster. It's standard "rack rocket" design. See it at the bottom of the page here:

https://www.tripolicharlotte.org/june_2002.htm

Also, check out this 5 stager by Rich Pitzeruse:

https://rmpitzer.syr.edu/rockets/flea.html

Enjoy.

 

[wwattles]

Okay, I found a better picture of it here...
rack rocket (Thallia)

Here's how it looks like it works:
Each engine ejects down the rack after burnout, which slowly shifts the CG forward. The Krushnik effect is negated by the fact that it's just a "rack" that allows a large quantity of air to flow past the motors. I guess the only dangers would be a failed ejection or a failed ignition. It looks like there's no recovery device on board, but it may be light enough to not need one (tumble recovery of some kind). You could probably add a nosecone with mylar streamer stuffed inside of it.

Am I getting this right, rstaff? Dick? You out there?

WW

 

[Rocketjunkie]

I did a 5 stage rack rocket using G160SS motors. All the motors burned but even though the rack was made of glassed phenolic, the rear got burned off by the time the last motor ignited.
Way cool flight though

 

[Mike]

I saw a 14 stage model last year, from the same guy who built the Commanche 9...this one wasn't as sucessfull although all stages did light!

I *think* the NAR Safety Code only allows up to 3 stages though.

 

[jetra2]

Actually, there's no limit on staging. It is just recommended that you stay at three stages because after that, the rocket starts to become too heavy to fly straight. Int he handbook, in the chapter about staging, there is a little bit of info on this subject of more than three stages.

Jason

 

[Micromeister]

Jason is correct: the NAR Safety code doesn't even mention stages. but the Nar does recommend a max of 3.

I've flown 5 stages, seen many 4 and 5 stage model including the the vid of the 9 staged commanche.
What I haven't seen is any proof of a successful staged flight where the model actually took advantage of the additional stages above 4. Every 4+ staged model I've seen is flying nearly horizontal but the end of the forth stage...One of the reasons the NAR suggests sticking with 3 stage to get the best chance of a Vertical flight. having 9 stages ignite is one thing... to put the model at extreme altitude with those additional stages is quite another.

 

[Mike]

Ok, thanks for putting that straight John 'n' Jason.