Remote Controlled missile?

[dongfang]

Hi,

Did any of you ever hear about anyone building a projectile with folding (or fixed) fins and an R/C receiver and launching it from a spud gun?

Just like model aircraft, it wouldn't really have a purpose. Just satisfying a little curiosity.

I could imagine the R/C doing some or all of:
- Trajectory control. Would probably require a gyroscope w/ signal mixing, to keep the thing from rolling around its longitudinal axis.
- Parachute deployment

Would the R/C stand up the the acceleration, or would every component and every wire be stripped off, and all gears in all servos be distributed over a large area ?

Something like the Russian tank-to-tank missiles that a launched through the cannon - except that there's no rocket.

Opinions welcome.

Regards
Soren

[jackssmirkingrevenge]

Your best inspiration would be rocket gliders, have a look here for some inspiration. Of course spudgun acceleration is much less gentle than a rockets, but it shouldn't be too hard to adequately protect the electronics , and the idea of reduced drag during the "boost phase" is true for both cases.

I think a projectile would be too fast to control as a "guided missile", it would make more sense to use a spudgun to launch it to altitude then have it configure as a glider for the flight back down.

[SpudFarm]

and it will spin going to every direction and sircles if you "turn"

[dongfang]

Hi,

OK thanks for the idea with rocket gliders. I didn't know about them.

Hmm maybe a low-pressure, huge chamber and long barrel pneumatic is a solution.

Spudfarm, about turns: I imagined to have an automatic thing that holds the thing fixed around the Z axis (the one going up from the barrel).

There's only pitch and yaw to control .. and only for a very short time...

Regards
Soren

[SpudFarm]

but you know..
it will spin 360 degrees around itself (like a rifle bullet) and if you turn up up soon becomes down.

[D_Hall]

Not radio controlled, but yes, people have launched rockets from spud guns...

http://www.creamyrobotgoodness.com/jujubee/

[jimmy101]

If you are serious about trying this you should start with what the water rocket folks do. I know they launch unguided gliders from water rockets, someone has probably launched an RC glider.

Water rockets have somewhat lower G forces than a typical spud gun but it is easy enough to slow down a spudgun.

You shouldn't have that much trouble controlling the axial spin of the thing. Water rockets don't general spin all that much.

[D_Hall]

You shouldn't have that much trouble controlling the axial spin of the thing. Water rockets don't general spin all that much.

You still need some form of roll control. The very act of commanding something that looks like a traditional rocket to turn will (unless you're VERY lucky) induce it to roll. So even if you come out of the barrel with zero roll (and I see no reason to suspect this wouldn't be the case), when you command a turn you'll induce roll UNLESS you get damned lucky and happen to command a turn in the direction of the natural cruciform (doubtful to pull that one off).

[trollhameran]

why not have a very short barrel and then have the rocket or whatever slot over the end of the barrel so that it doesnt have to fold up to fit inside the barrel

[daxspudder]

Well, Ill just have to build one and tell you what my results are. Im thinking of using a caulk tube with spring loaded hinged wings that will deploy upon launch, the hinges will be build into an axle that is servo controlled(x2). Of course movements will have to be tiny at 600fps when fired from my 2" combustion. Maybe (trying not to break site rules) using a D-type rocket engine with a 1-2 second fuse to sustain flight for a short time. But ill probably be too lazy and forget about it, i think it could be done.

[jimmy101]

You shouldn't have that much trouble controlling the axial spin of the thing. Water rockets don't general spin all that much.

You still need some form of roll control. The very act of commanding something that looks like a traditional rocket to turn will (unless you're VERY lucky) induce it to roll. So even if you come out of the barrel with zero roll (and I see no reason to suspect this wouldn't be the case), when you command a turn you'll induce roll UNLESS you get damned lucky and happen to command a turn in the direction of the natural cruciform (doubtful to pull that one off).

You are right, if it is shaped strickly like a rocket. However, a rocket really doesn't have to be "rocket shaped". With suitable fins won't it look like an aircraft?

It comes down to what you are trying to do. An RC "rocket" is kind of silly anyway, the velocity is probably too high to be controlled by a person. And, since a true rocket has very little lift (especially an unpowered rocket), the flight time is based on ballistics. An RC plane/glider is the only way to get the thing moving slow enough to be human controllable. Furthermore, since the shape provides lift you can actually fly it for more than the few seconds that the ballistic flight of an unpowered rocket would have.

[D_Hall]

While I agree with you on the controllability of a rocket... I assure you that simple rockets can generate insane amounts of lift. Keep in mind that the only reason airplanes have such big wings is because they have to fly slowly (to take off and land). Remove that constraint, and you find that you don't need very large fins/wings to do some pretty spectacular things.

[TurboSuper]

Won't the servos and related electronics screw up the rocket's center of gravity a bit? Also, hobby rocket motors (at least those available without a license) aren't meant to handle alot of weight.

[D_Hall]

Won't the servos and related electronics screw up the rocket's center of gravity a bit?

Not if you do it right.

Also, hobby rocket motors (at least those available without a license) aren't meant to handle alot of weight.

True, but these days RC servos don't exactly weigh a lot either.

[BigGrib]

I think it'd work probably be best to use a multi stage rocket and then controll it via remote after the velocity has decreased enough to where you could controll it easily without killing someone