RC Rocket pod

[Mera'din]

So I have tried a few searches and didn't find the exact info I'm locking for. I want to setup a switch on my transmitter to opperate a few things on a plane. I'd like to turn on and off navigation lights, and then also be able to eventually launch some bottle rockets or other fun stuff. Nothing illegal, jusy hey look what I can do stuff.

In school we build model rockets that used a little metal lead that when you applied a battery current to it it got hot enough to ignite the rocket engine. Is is possible to rig one of those up to a open channel on a rx and use it to light a bottle rocket?

What would it take?

[gromitvt10]

Mera,
I know you'll get a lot of flack for attempting to launch bottle rockets off of a RC airplane..Yes it is against AMA rules. But...lets just say i know someone who has done it over a totally unpopulated area. This person used an onboard On/Off switch which was connected to a heating element (wire that produces heat when electricity is applied, same ones used in model rocket igniters). The element was wrapped around the fuse of the bottle rocket. When the switch was turned on, the wire got hot which lit the fuse and...swoosh. Off came the bottle rocket. There is some delay, b/c of the time it takes to heat the wire, ignite the fuse and for the fuse to burn.
That being said...It is NOT allowed by the AMA!!!

[Malc C]

So I have tried a few searches and didn't find the exact info I'm locking for. I want to setup a switch on my transmitter to operate a few things on a plane.

I can't believe that a search for "rockets" or "RC Switch" didn't give you any results like this (http://www.rcgroups.com/forums/search.php?searchid=17466261http://www.rcgroups.com/forums/search.php?searchid=17466261) or this (http://www.rcgroups.com/forums/search.php?searchid=17466263)

An RC switch is quite simple, especially if you have access to a PIC programmer, but there are lots of alternatives, the simplest being a servo activating a micro switch.

As the other poster mentioned, firing live rockets is controlled by regulations that vary from country to country, and most make it illegal to fire rockets from a flying model, so you would need to make sure you don't bring yourself or school into trouble

[Mera'din]

I am not a member od AMA, I fly on my family's farm so I am not too concerned with upsetting anybody. We are not going into this will ill intent nor are we using explosive tips or anything. Nothing diffeent than shooting of bottle rockets during the 4th of July Holiday. Only rules around here is it is illegal to buy them during certain months for residents and you cannot fire them within citi limits.

As far a seraching goes. I have found some info, just not eactly what I'm after. I was using "rc rocket launcher" which might have been my problem.

I am not too interested in a servo activated device, more of a switch that will heat up an element like suggested.

Thanks for the words of caution, I will be careful!

I have seen the videos of some of planes launching rather large model rockets...YIKES! I have nothing like that in mind.

[Mera'din]

Also, your searches links had no matches.

[Mera'din]

Worked if I did my own search rather than following your links.

A alternative to launching rockets would be to mount some rocket engins on the plane and use them for a little rocket booster, thoughts on that?

[Malc C]

I am not a member od AMA, I fly on my family's farm so I am not too concerned with upsetting anybody.

To be honest that comes over as being somewhat arrogant :rolleyes:

Every country has different approaches to enforcing rules and regulations, and whilst your AMA has set down guidelines on the use of rockets or other self propelled objects from a flying model, no one can say how well they enforce that rule, unless it incorporates some statute by-law in which the matter can be passed to the police. The other side of the coin is that generally (if its like our BMFA here in the UK) members are covered by millions of £ / $ worth of insurance, so if there was ever an accident you *might* be covered (which I really doubt if others are saying what you are doing is illegal )

Rocket powered aircraft is a different thing, and something that, as far as I know is perfectly legal, but no doubt there are still guidelines on what type or size / thrust rockets can be used for a given size of model

Glad you found some links after all :D

[BushmanLA]

Screw the AMA.
Have a ball, this is America where we do whatever the heck we want unless there is a law that expressly says we can't. Even then, sometimes we do it anyway. :D

http://www.youtube.com/watch?v=jWEbbUczrYQ

http://www.youtube.com/watch?v=Hfoq065GXRA

http://www.youtube.com/watch?v=jJKeWovxruU

[Ron W3FJW]

Looks like a new phase of air to air combat is born.

[Mera'din]

I actually saw those vids and that is what got me thinkng about this. When I say upset anyone, I'm not being arrogant, just there are no neighbors to annoy.

[quigley257]

I was "involved" with something similar back in the day. The bottle rockets(12 at a time) were simply taped together at the fuses with an Estes ignitor taped in at the same time. The rockets were then slid into a PVC tube with a wire run in from the rear which was connected to a servo operated micro switch. Great fun and quite safe when used responsibly after a good rain.

--quigley :D

[Mera'din]

Bushman, what did you use to launch the rockets? Is this something that you made?

[BushmanLA]

Yeah. I used little PIC microcontroller but you can find other ways of doing it. A common RC speed controller for DC motors would work just fine probably.

For ignition I used the standard Estes rocket igniter that comes with the rocket motors.

[Mera'din]

Do you have any info on this pic thing. As you can tell, I don't really know much about that.

[BushmanLA]

Do you have any info on this pic thing. As you can tell, I don't really know much about that.

Unless you want to learn to program, buy a PIC programmer, and learn all softs of other stuff, dont bother.

Just use a RC speed control for DC motors.

[liam2317]

So what do you guys think of IR guided rockets fired off an RC plane (or to start, fired off of the ground) at another RC plane with a whole bunch of IR diodes on the back of it? Is it feasible or not? I have read about "sun-seeking" model rockets before, it seems like the same idea could be applied to this project...... maybe?


Let's say that no one is really going to try make one, its all hypothetical... because if this doesn't break some laws, I don't know what will. :D

[shuttercat]

I'm a rotary-wing pilot, and I've been considering doing a scale Comanche with rockets, controlled with an onboard AVR microcontroller. I've done a little development on the Arduino platform ( http://arduino.cc/), and find that it's very easy, and exceptionally well supported, with code and circuit examples readily available. Some electronic circuit design and programming experience strongly recommended.

For model aviation use, I'd recommend the lighter varieties of the board:
Arduino Nano (http://arduino.cc/en/Main/ArduinoBoardNano)
Arduino Pro Mini (http://arduino.cc/en/Main/ArduinoBoardProMini)
or
Modern Device Really Bare Bones Board (RBBB) (http://www.moderndevice.com/RBBB_revB.shtml)

I have a RBBB and it weighs, with male headers installed on the bottom for breadboard use, power jack and voltage reg installed, 14 grams. RBBB can be cut down extensively, details on the product page. However, I suspect that the Nano and Pro Mini, stock, are lighter than you can make the RBBB with mods.

Anyway, I'm still torn about rocket design and ignition. I do like the idea of bottle rockets in slender tubes, but I may use CF instead of PVC. I also prefer nichrome wire to model rocket igniters, but I'll run tests to see what works best anyway. The conductivity of CF may cause difficulty for electric ignition, or I might be able to use it in some way.

Clearly, this project is still just a gleam in my eye.

OH! Right, guided rockets. I don't know, it sounds expensive. I remember reading about the earliest laser guided bombs - the optics divided the image into quadrants and each had a simple detector of some sort. Ideally, the laser would be projected (from the aircraft?) onto the ground, being detected by one of the, err, detectors. The control system would throw the control surfaces hard over to steer the bomb toward the activated quadrant. (see Bang Bang control (http://en.wikipedia.org/wiki/Bang-bang_control)) Simple, but worlds better than dumb bombs. Perhaps you would use IR LEDs on the target and optics similar to http://www.dealextreme.com/details.dx/sku.1915 with IR receivers. (note: I'm fairly sure that this part could not work without substantial modification) I suspect that finding a stock part to make your "detector array" would be a huge challenge, and I wonder how cavalier you would be about firing it in combat if you weren't sure about getting it back. Anyone with better ideas about detecting the direction to the target, whether generally or precisely?

[Brandano]

You could use IR emitters and detectors, but you would need to filter out the sun. Probably transmitting a modulated signal and detecting it through an appropriate filter could work. Lazer tag toys seem to manage to discriminate between their signal and other IR noise, so their circuitry could be a good starting point. RC laser guided bombs sound interesting too, a laser diode can be modulated like any other diode. I believe that either thing is dangerous, and probably could cause some legal issues...

[shuttercat]

You could use IR emitters and detectors, but you would need to filter out the sun. Probably transmitting a modulated signal and detecting it through an appropriate filter could work. Lazer tag toys seem to manage to discriminate between their signal and other IR noise, so their circuitry could be a good starting point. RC laser guided bombs sound interesting too, a laser diode can be modulated like any other diode. I believe that either thing is dangerous, and probably could cause some legal issues...


The real design challenge is detecting the direction to the target. IR detectors are designed to receive omnidirectionally, so that your tv remote works from anywhere in the room. I've researched DIY laser tag and it works by receiving (the targets/vests) omnidirectionally and transmitting (the taggers/guns)with a well-focused emitter. The basic premise is of an LED in a tube with a lens at the end.
If you can lens them to detect a smaller cone, you could have four detectors pointed at the forward quadrants and compare the amplitude of the received signal in each of them to determine which one is closest to the direction of the target. It's a long way from azimuth and elevation, but it might be a good start.

[liam2317]

My idea for finding direction was much like what you suggested shuttercat; simply embed the detectors into the nose of the rocket and have the directional ones at an angle so they would pick up the signal when the rocket began to go off course. Then use their input to tell which control surface to move (and maybe even how much to move... though that sounds a lot harder to figure out).

To me the main challenge seemed to be actually controlling where the rocket goes. Rockets go extremely fast and so I would expect they would require very little actual control input, especially when using IR as the range is quite limited. This could make fine tuning the control system very difficult! I would expect the first few prototypes to go all over the place.

I'm not going to lie to you, I know very little about how electronics work but I'm learning. :p

Anyway, here is a quick drawing I came up with a while ago well thinking about how to make this work.

[AndyKunz]

A friend of mine, Sean Breheny, did somethink like this several years ago. If you google, the link will likely be on piclist.com.

Remember in the NAR code, you don't target anything with a rocket. You might want to intentionally NOT hit your emitter.

And yes, a modulated signal (38kHz is a common one) is a great way to get around the noise.

Andy