Originally posted by stymye
by spin vanes do you mean a screw -like shape,rather than fins
so the rocket would basically screw out of the tower?
seems like the rocket could sustain a higher rate of spin than a typical model,,interesting
the trick would be keeping the rocket from wedging inside the tower or wasting it's thrust as it makes it's way thru the tower
neat idea,but sounds very tricky
Some explanation is in order, since pictures aren't ready.
It looks like a jet turbine engine. The outer body is only that -- a smooth 1.6" tube about a foot long. Inside is a minimum diamater 18mm bird. Instead of fins, it has turbine vanes holding it in the middle of the outer tube. It contains recovery gear of course. The outer tube covers everything except the very tip of the nose poking out. Up it goes and the whole thing spins.
I've given it six vanes near the top and six near the bottom. With nothing outside but round tube, it'll be free to rotate while still in the tower. The rails are 4 foot tall. 3 foot is usually enough for a fee fall bird to get going, so I'm betting within 4 this thing should be getting its fair share of aerodynamic action. Could probably even be tube launched.
The vanes are canted at about 10 degrees. Also, they're beveled on opposite edges to increase the cant a bit. Just guessing, I'd say it's going to get a lot more than 300 RPM. The aft of the engine is recessed an inch inside the outer tube, to bring the CG forward a little. Between that and the spin this should sound pretty impressive. If it works out I'll try an MPR bird, canting the aft vanes more than the front, to increase the air flow, and try an intake and nozzle arrangement on the outer tube. If I can get it to pull air and use that to add some altitude, it'd help overcome the atrocious drag of the thing. I might could add some weight around the outer tube to give it some momentum.
But not until after I'm confident this thing won't just drill core.