tango28charlie

The rocket motors in question have about 2 pounds of thrust and a burn time of under 2 seconds. I don't think that much thrust acting on one wingtip for that amount of time would throw the average sized scale jet out of control. The way they were mounted on the F-16 wingtip, the exhaust flame would not do any damage to the airplane either. Also it is unlikely that the rocket would fire later, like on final approach like one person suggested. The igniters aren't like a fireworks fuse that can smolder for minutes. As soon the igniters fire, the motors fire too. If the igniter isn't touching the rocket propellant then the igniter will fire but the motor won't. There will be no 'hangfire' in the nozzle to cause a delayed ignition.
Charlie

MHall

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I'm game! Light um up!!!!

E.C.

Cool idea.
I once tried launching small firworks from a .25 little stick. Most of the times it would stay in the launch tube because the plane flew faster then the fireworks could. Only when flying near stallspeed it worked. Never had any damage tough.

Falcon 64

Of course, a fool proof system is required here. It`s not that easy to load it up and go firing whatever you want to blast the sky. Thourough checkouts is of course a must.
You allways have the glitch possibilaty, wich may fire them up...
Caution is required here, but once you have fired a missile, it`s on it`s own..
Be sure of the direction, or have a insurance equally to the one we have in Norway, 1,5 million dollars, third part insurance.....

Regards

Gudmund

steakandale

I'm really surprised this has not been SLAMMED from an admin or senior member yet.
As far as I know (can of worms there, I know) rockets fired from an RC aircraft are an AMA no-no as well as a Rocketry no-no.

If you put the slightest forethought to it, you will realize that there is a lot of room for bad things to happen trying it.
Rockets aren't supposed to be fired from ANY moving platform, or fired at less than a skyward angle (theres a definition in degrees for that too, but I don't recall it from memory)

I've done the rocket thing too (model rockets, not launching from a plane), and they do have ignition miss-cues and hangfires -
just the ticket for hosing down the flightline
[X(] "Nice Rocks' Snake Six!!"

I suppose if I had a dry lakebed all to myself... - it would be a hoot - but I'm pretty sure its a "Bozo no-no"

SAP_2000

Well. Fortunately we got no AMA here in Norway where the tests are due..... Maybe that is the reason....?[8D]

wojtek

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thats because this is not comunism, and people are allowed to exchange ideas (well for the most part here on RCU )




Wojtek

MHall

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I still don't understand what guys don't get about the AMA is not in control of what you do with your R/C Aircraft off of an AMA controlled site. If you go fly off of some private piece of property or out in the desert, the ONLY group that can say anything would be the FAA. If it leaves the ground then they can step in. The AMA only controls insured sites and if you have something happen and try to use the insurance they will see if you where playing by the rules. If not, then you're on your own. So lets all get off the AMA kick, go find a private piece of property or hit the desert and have a blast!!! [8D]

seanreit

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Couldn't agree more Mike! I've flown off private property before, it's fun! I've run a bunch of small stuff with no mufflers, tearing stuff up, having a blast. My friend that did the weedwacker, clearly off private property, had a bunch of fun with that!

I say fire'm up boys, just "don't shoot your eye out, kid"

rcjetfan

Finally someone that see's the actual perspective on the AMA... If your flying from a private field or in the desert theres nothing the AMA can say or do to you. For you guys that live in California and are ever in Samoa or close to it. Theres a private airfield less than a mile from my house that I fly at all the time and the owner is a crazy guy that ..well..lets just say he likes things that make a boom every now and then and flies his own r/c aircraft. He has a modified P-51D that will actually shoot mini-rockets from the wings..awesome site to be seen. So if you guys and of course gals that want to fly without the worries of the so called big brother looking over your shoulder.. Let me know and we can rent the field for a weekend. All I ask is you give me 2 weeks in advance notice to get it set up..

Falcon 64

We`ll see about that. My first round of AIM-9èrs, is very close. I have made a system to fire the four on one servo. I`ll be back on this later. Of course, one by one, and not the bunch in one blast...

Regards

Gudmund

wojtek

My Feedback: (73)

be carefull Mike,

I was almost kicked off of RCU because of bringing up your exact point .... I fly without a waiver at a non AMA site, and stating this publicly upset people so much there were requests to block me from RCU ( part of peoples problem with me was also that i was puthing a rather large engine on a particular airplane, but no one seamed to understand that this was based on a recomendation from both the plane and engine manufacturers ... ) , i also had people emailing me , threatning to shoot me down wherei fly ... .. I dare not coment on this rocket topic!!! , and im surprised this thread has not yet been closed ....




Wojtek

F106A

My Feedback: (2)

Hi,
The X-1 is DROPPED, not fired, off the B-29. The X-1 is controlled by a seperate radio: the model glides down, under control, the rocket motor is fired, burns out and the X-1 is landed. There is nothing excluding a rocket propelled, radio controlled model airplane in the safety code.
BRG,
Jon

Balsa Master

the x1 rocket is guided after launch... the rocket is not. i dont understand this either since it is ok to lauch rockets off the ground... however the rule exists because a potential launch could happen due to strange curcumstances in a horizontal or downward direction causing a poweres lawndart and the potential for SERIOUS injury and inevitably a non AMA covered lawsuit....


absolutly nothing, the total impulse, even on the outer tip of that wing is NOTHIGN compared to that jet engine on the back putting out like 100 lbs of thrust...


um... sure... i do the REAL thing, ive poured my own N engine... and i no for a FACT that rockets that mis ignite can (quite often in fact) sputter if the fuse is improperly inserted then light up and fire... dale is right

and last time i browsed through the FAA rule bood (long long time ago) there IS a statment about airstarting projectiles from a moving platform (not to mention... its theorieticly a missile at that point)

the angle that was mentioned b4 is 30 degrees from the horizontal.

if yo ustill want to do this... set up a mercury switch in your fire system that disconnects the system if the plane is under 30 degrees from the horizontal just to be safe. however i wouldent dare fly it on over a c... the d - g range have the power to do damage to internal wing structures as well as light the wing tip on fire (who ever said a launch that didnt eject woulent damage the wing is out of their mind!)also... lets just pretend that your planes flying close to 200 mph... that little launch rods fonan be at such a high frequewncy vibration by then that you could damage your radio wit hthe vibrations (long mettal object, significant mass, high frequency vibration... BAD) next, what prevents your rocket form veering off course and heading down due to wind conditions? next, lets again say that your plane is flying at 200 mph... that rockets NOT gonna leave taht launch pad... i just want you to know that now. even if it fires all its gonan do is push it self a couple inches down the rod then stall out and cause EVEN MROE FLUTTER you will crash this plane if you try to wing launch that way.

now.. i already c this question comming up... why does that other planes wing laucn work?
answer... SMALLER ROCKET and if u look... its only barly going faster than the plane...

MHall

My Feedback: (7)

Wojtec,
I am sorry if somebody does not like the facts, but that is all I said. If somebody where to try and have me removed from RCU they better go reread the First Amendment!! Also, this Web site is based in the United States of America and unless I missed the removal of our government, I think the Constitution still stands. I only stated facts nothing more. I also shake my head at the fact that the gentlemen who started this whole thread is NOT in the US!! We can give him any advice we want to and he must figure out if it is legal where he lives. It is things like this that really get me mad[:@] I'm done with this thread.

tango28charlie

Well, Balsa Master, if you've indeed "poured" your own N "engine" you would know that high-power rocket hobbyists generally don't "pour" propellant, don't call rocket motors other than Estes ones "engines", and don't use a "fuse" to ignite them. You'd also know that there's a big difference between igniting black powder motors like the ones being talked about on this thread and composite propellant ones. That N you "poured", I'm going to go ahead and assume that it was composite propellant. What was the propellant formulation you used? What was the propellant mass, and what was the Kn? What material did you use for the nozzle? Did you use a commercially available casing, or design your own? If you used a commercially available casing, what brand was it? Since your propellant was pourable, what solids loading did you use to make it so? Did you add any plasticizers to the propellant to improve its pourability? If so, what were they? Did you vacuum degas your propellant? It just so happens that I've flown rockets weighing over 90 pounds and with up to 34 pounds of propellant, launched well over 3,000 rockets, and successfully launched black powder model rockets from an R/C airplane. Have you done the same? If not, then don't try and act like I don't know what I'm talking about.

You seem to take issue with the fact that I said the flame from the rocket would not damage the wing of the airplane. If you look at how a rocket is mounted on the wingtip of the F-16, you would see that the flame would be totally behind the wing if the rocket didn't move. Also you don't need a long metal launch rod to whip in the wind and cause all kinds of aerodynamic and radio interference issues. A launch rod is there to allow the rocket to build up enough speed for the fins to begin stabilizing it. Launching it from a moving airplane, you would not need a rod any longer than necessary to keep the rocket in place until the motor ignited, but I'm sure an esteemed N-engine pourer like yourself would know that already. I used 3/16" diameter wood dowels 4 inches long for launch rods when I launched rockets from an R/C plane. If you don't think a C motor would have enough power to move the rocket forward against the drag on it caused by the plane's motion, then you could either calculate the drag force on the rocket and compare it to the motor thrust, or use a larger motor. I've flown 1 inch diameter rockets faster than Mach 1 so I'm sure I could come up with a motor with high enough thrust to make it leave the plane. If you think this can't be done from a technical standpoint then you sir are the one who is out of his mind. By the way, if you check your facts, you'll see that model jet engines do not develop 100 pounds of thrust.

As far as the AMA and FAA, I know that launching rockets from an R/C plane is illegal as hell as far as the AMA is concerned. I have no idea how legal it is FAA-wise. Therefore I would not do it at an AMA sanctioned event, or if there was an FAA inspector standing next to me.

Charlie

Balsa Master

amonium per chlorate and polybutal dyline (spelling?)
black rock desert win a power mixer 500 feet from my van... and yes you do pour them becuase as you mix the oxidiser into the rubber a chemical reactrin starts that melts the fule down into a paste then you pour it into slugs and isert them into a fiberglass or steel(illigle) seperated by ruber gaskets... i use thermal light with a diped in propellent of the same chemical make up as above... 3000 degree ignitor gets it kicking ya no?

aluminum dust wasadded to propelland to increase pressure in nozzel. (nice white flam too) the nozzel was one piece graphite it was in 1989 and was in a standard fiberglass cassing. oh and your 3000 rockets in nice and impressive in all... whats ur trippoli number (aprox, dont need to give out details here)

and as for the pressure... i dont know... it was 89...

oh... and lets cmpare the flexability of a hard wood dowle and a steel rod... do that for me?

not gonna burn the wing eh? ur gonna have nice fiber glass bubles fro mthe heat and a toasty trailing edge...



oh... i also beleive that im on the balls 91 tape if you wanan take a look... im not gonan tell you who i am... just know that there were no wimpy rockets there... at the time it might have been called the LDRS launch and not BALLS dont remember

Mi-25

Hi Gudmund/Tor...
I think this is a really great idea - and one that will please the spectators no-end.... However, have you thought about the potential future problems turbine jets might have worldwide - I mean from the regulating authorities.
If influential people (who usually don't like or know nothing about our hobby) start getting ideas of 'terrorism' in their heads - who knows what restrictions may be placed on our great hobby?
AMT now sell turbines with huge thrust - and if evil minded people get ideas???
.. I was just thinking that the LESS attention we draw to ourselves the better!
cheers,
Leon

tango28charlie

A more appropriate description or motor making might be that you start with a liquid binder which begins solidifying chemically when you add the isocyanate catalyst to cure the propellant. Once you add the solids you do end up with a paste which is generally more clay-like and packable than pourable for competently designed motors. My Tripoli number is in the 4000's.

What of the flexibility of hardwood dowel versus steel rod? With a 4 inch long piece neither would be particularly flexible. The rod in the picture you included is much longer than necessary. The launch lug on the rocket should be at the C.G. of the rocket and the launch rod only long enough to extend through it.

Using an 18mm type C or smaller Estes motor in the drawing below you would get some scorching on the block behind the rocket from the exhaust, if the rocket did not separate from the airplane. The only thing is, an Estes B6 or C6 motor would have more than enough thrust to separate the rocket from the plane. Doing the drag force calculation on a one inch diameter rocket, with a coefficient of drag of .75 (ballpark figure for a rocket with no transition sections) with a sea level atmospheric density of 1.29 kilograms per cubic meter and an airplane velocity of 90 meters per second (200 mph) you come up with a drag force on the rocket of just over 2 newtons of force. Since a B6 or C6 motor has 6 newtons of average thrust and an initial thrust of 13 newtons, it is obvious that it would have more than enough thrust to accelerate the rocket forward from the plane.

Charlie

SpiderJets

So Tor, now you've apparantly been able to open Pandora's box, tell me, when are you going to test it in Norway and show us the pics/vids ? I'm curious to see. I guess we all are.
PS. I launched some fireworks too from an R/C trainer when I still was a kid,... the things were so slow and so little that my prop plane almost flew faster at idle... but I was having a ball with this... the next weekend I enjoyed myself dropping eggs and small pebbles from a balsa belly box operated by a servo. Most of the fun was to bet with my friends if they would be able to catch the eggs without breaking. Besides, being a young kid at that time, the tiny fireworks costed me a major gap in my very limited hobby budget, whereas the eggs were plenty and freely available in mothers fridge. Hehehe.
PS. This time I would not make a mix video, showing the launch of the missile from your R/C plane followed by a sequence of explosions taken from movies like Terminator... or I guess it will be hard for you to attend a jet meeting in the US one day.

All the best.
Nicolas.

SpiderJets

Am I dreaming now, or is there a part of thread that has suddenly been deleted ? (With the chemical side of the rocketry ? I was just about to start sanding some scrap aluminum to dust... hehehe)

Best Regards,
Nicolas.

icepilot

Good morning Nicolas!

I can tell you that the plane has now flown with the rocket on the wing tip, just to check stability! It flew just great, I had to trim it a little because I only had one rocket, producing a little drag on the wing.

If and when it will be fired is not clear yet. A couple of times every year we are able to borrow a military air strip far away in the forest, and I will propably test the thing there next time! Whether this will be before the snow falls or if I will have to wait for spring to thaw us up again is uncertain. [&o]

Anyway, it's fun to see the discussion that has followed this - like I said in the beginning of the thread, I will test this far away from people, with the plane going more that 45 degrees up and myself and my caller even with helmets!!

I am also thinking about using a very thin, self-adhesive aluminium sheet on the wing tip and the launch rod end to protect it from the rocket blast. I am 100% certain that the rocket will leave the launch rod in a 1/10 of a second, but just in case, it would protect the wing from being scorched.

So, you liked the new movie? There will be more in the near future!!

Best regards, Tor

SpiderJets

Wooooww. Great. I happened to be flying with Nicholas The and his friends last Saturday in Jakarta, was great fun and the smell of burnt kerosene was like sweet ladies' perfume to all of us. Frankly speaking, they were flying jets and I was trying one of his trainers as i am flying Mode 1 and they Mode 2. [:@] I hardly could do any damage anyway because this prop plane has such a horizon stabilizing device so it almost landed by itself too. [:'(] No fame and glory to be collected from this one ! [&o]
I have posted some pics on my website (and a new link to your creative movies as well... never seen before). I am now in Bangkok and except for some very few manufacturers here (and very limited number of jet pilots), there is no jet flying to be seen here . Nicholas flew his SJ-16 for the first time, was a bit nose heavy so landing was very fast but flawless. With the JetCat P160, he used (except for take-off) only between 20% and 40% throttle... so far ! Luckily this rocket is not using solid fuel so he does not even have to be concerned whether or not to be flying under the AMA regulations !
And about you movies... keep'm coming... we like new blood with new ideas ! [sm=thumbup.gif]

Ciao!
Nicolas.

irongutz

google rcgeddon and you'll find a lot of this stuff.

j.duncker

My Feedback: (2)

irongutz this is a 6 year old thread you have resureccted.

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