Remote Controlled missile?

[dongfang]

Hi,

Thanks for the great ideas. To cut it short, I think I will try to build a water rocket now. First, uncontrolled and later controlled...

Fortunately, I can re-use many materials and tools from pneumatic spudding, not to mention experience.

Regards
Soren

[rcman50166]

Well I know that RC servos can take the hit from a shot or, at least, RC car servos can. I know a thing or two about RC equipment. (look at my username) They are designed to absorb collisions and will hold up fine. These size servos also have more than enough torque to handle fin deflection. The only thing I would worry about is horizontal stability. Front to back is easy but side to side, well not so much. You have to make sure the aircraft will be belly down before you control it. This is achievable by lowering the center of mass below the wing line. If the flight is not immediately stable after leaving the barrel the the craft may desintigrate and seeing as manuevering the belly of the craft down requires a controlled instability, this will be a challenge. The other thing that would worry me is the range. If the projectile leaves controllable range, well, your f*cked. Remote control servo systems are designed to remain in its last given position before leaving range. So, basically, you have to hope that your not turning the vehicle while it leaves the range of your controller. Just prevent this problem by using an RC plane reciever and transmitter. They have a range of nearly a half mile. Also, keep the projectile in line of sight. I also used to do high powered amateur rocketry. I know as soon as you put steering on it the rocket becomes a missle which is illegal to launch up until the military. So I would just keep it a glider. This way, should you cause trouble, which happened to me every other rocket launch, you will be able to ensure the authorities that you are not breaking any laws. It will also make it easier to control.

[mike1010]

the best solution from my years of rc plane building i to try controlling the rocket at the height of the shot. let it go until it reaches the top and then take control, however without wings you might have a problem with controll. i might suggest a cannon barrel with slits on the side for wings and a custom, slope glider design or other hard light fiberglass plane to hold up to the forces involved. i fly an excite f5j hotliner and that thig cooks so if you build something strond you might be able to controll it really well.

[dongfang]

Hi,

rcman, I appreciate your information on the servos.. My first idea was just a misile with only tailfins, and a long enough body to have a little "lift" when the tailfins push the axis of the missile off the direction of the oncoming air... and with some sort of gyro spin stabilization, so I have a chance of following what is X and Y. I would, of course, only have a couple of seconds of controlled flight.

But a glider plane would be much more fun! I remember seeing WWII German film clip on TV some time - German scientists experimenting with a delta-wing aircraft, launching a quite small balsa / paper model off a catapult. It glided beautifully (and fast!).

It could be cool to have real wings .. something like the German model, or resembling the F-104´s

My idea now for an initial experiment is something like a delta-winged water rocket, then later upgrading it to cannon launched.

Hmmmm what do you make strong aerofoils out of these days (I´m quite a bit behind; I didn´t build gliders for decades, and my RC planes (elapor and styropor) now are my first ever!) Mike, you mention fibreglass. Yeah that could be an option... and I think you are right that slits in a barrel don´t ruin it completely.

Regards
Soren

[ammosmoke]

Well, you can do what they do for sidewinder missiles. Put tiny wheels on the tip of each wing. The gyroscopic force of the spinning wheels keeps it from rotating.

About putting slits in the barrel... Foldout wings anybody?

[mike1010]

foldout wings are cool in theory but not practical plus there is more strenght in the solid wings an less moving parts. at the speeds possible flappy wing springs could be a huge problem.