"FlippiTwin" Breech-Launched Sustainer/Booster Combination

Has anybody ever seen or tried Aerocon System's "FlippiTwin" breech-launched sustainer/booster combination? Imagine a FOLDING FIN sustainer rocket that's INSIDE the booster's body tube. At booster motor burnout, the sustainer squirts out from WITHIN the body tube, the fins fold out, and the sustainer motor ignites! See the web site https://www.aeroconsystems.com/rockets/flippitwin.htm , and the attached drawing. The system uses a 29mm booster MMT (for an Aerotech Econojet F motor, say), and a 24mm sustainer MMT (for an Estes D-12 black powder motor).

I know that people have "shot" rockets out of PVC water pipes, but this is a different concept for mid-power rockets. What do you think?

Dluders,

I saw this a couple weeks ago when I was at their site ordering a year's supply of switches. This appears to be one VERY cool rocket, to the point where I will probably get one.

Carl

I would think that the sustainer would get quite a kick of acceleration because it is tube launched. Anybody else agree with this assumption?

according to the Rocketry Handbook anything tube launch has a quick acceleration and this is tube launched. It does seem like a reasonable assumption
This is a very cool Rocket and I think I may get one. The only problem is the hassle with the electronics. I haven't had very good luck. I have always been interested in a tube launched rocket though and this could be my chance to get one
hey doug...wanna do a project before or after the magnum

Maybe Ryan... I think we should build an conventional 2 stage composite propellant rocket first. A lot less can go wrong.

Originally posted by n3tjm
I would think that the sustainer would get quite a kick of acceleration because it is tube launched. Anybody else agree with this assumption?

Click to expand...

Yes, you would get some amount of acceleration, more than via conventional staging. I don't know whether it would be 'quite' a bit more.
Remember your high school physics and conservation of momentum? mass x velocity = mass x velocity
This means that in order for the upper and lower stages to 'kick' apart, the upper one will indeed receive a little extra increased velocity, but the lower stage will also get a velocity change in the opposite direction.
You would gain a whole lot more velocity if this closed-breech type of launcher was backed up against a sturdy mass like the Earth; then all the energy that tries to separate the stages would be directed to the upper stage (the only part free to move) and the velocity increase would be much greater.
My question about this rocket is a safety issue: I saw these folding-fin units on sale at CheaperThanDirt for $1 as surplus hardware. They are steel. Is it smart to place this much metal, complete with pre-fragmented sections (hinged fins, springs, pins, etc), immediately next to the motor. Yeah, I know it's an upper-stage feature, but upper stages do not always go up. In the event of a CATO, I know that I would not want to be in the neighborhood.

Aerocom Systems recognizes that the FlippiTwin (and the earlier FlippiFin) metal rocket fins do not conform to the NAR's "United States Model Rocket Sporting Code" (also known as the "Pink Book"). All NAR members should have received this pamphlet then they joined the NAR.

On the Aerocon Systems web site https://www.aeroconsystems.com/rockets/FFR_info.pdf , Page 2, here's what it says:

"Overview" -- "The FlippiFin is a breech launched folding fin rocket designed for vertical launch. It is not a NAR approved vehicle due to the metal fin can and can only be fired at Tripoli, private, or
experimental launches."