A wonderful wireless launch system. Cheap

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

LtSharpe

Well-Known Member
Joined
Nov 7, 2004
Messages
482
Reaction score
0
Hello all,
I recently got into rockets again after a 15 year hiatus. My first discovery is I prefer not to look straight up at the beasties as they launch. It hurts my neck and is more dramatic to see them ascend from a distance. The method I chose to overcome this is quite simple.

Get yourself a low priced complete airplane setup like the yellow bee from any online rc shop. Should cost you NO MORE than 50 bucks not including shipping, although they can be had for 40. This planes electronics work great for rocket launching. Yes you really can get a complete rc plane for this cheap.

What you do is take the guts out of the plane and mount them in a metal or plastic enclosure box from radio shack etc. The speed controller and receiver are all on one tiny circuit board. It has two outputs since it is a simple 2 channel 2 motor airplane. It normally flies by powering both motors at once to go up(they are angled downwards) and then powers one or the other for left and right. Anyway,, there are two pair of wires, one pair goes to each motor normally. All you do is use one pair of the control wires and extend them through the enclosure with thick wire at whatever length you want out to alligator clips. On mine I made the thick launch wires link up with the control lines inside the box for a clean finish. If you want a lot of length between the receiver and the rocket then you need to use heavy wire so you don't have as much voltage drop. You also need to run a wire to the antenna wire inside the box and then solder an alligator clip to it's other end. This you will clip to the base of your metal launch rod. It makes an absolutely perfect vertical whip antenna. You then run your two aligrator clips from the control line over to the ignitor and you're set.

Now, the important thing about safety is simply that you want a switch on the receiver which cuts all power to it. Once you have attached your clips to the igniter you go back to where the receiver is laying on the ground, TURN YOUR TRANSMITTER ON FIRST(although in my experience this setup is not prone to interference and I have not had a problem either way) and then flip on your receiver's on switch.

For the yellow bee setup you simply push the throttle control on the transmitter all the way one direction or the other(by default it's down but the reverse switch on the transmitter makes UP the throttle apply position, rather appropriate for rockets.) and WHOOOOSH up goes your rocket.

I have used this method to launch around 15 times or so now. It's all I use. I have never had a premature firing.

If you can't get a yellowbee setup cheap then I would recommend any FM 72 mhz setup but frankly a 27mhz am rig would work to but it MAY be prone to interference and your rocket could go up prematurely. THis is why it is very important that you make the length of wire going from your receiver to the rocket be at a comfortable distance.. this way if it does go off prematurely you are out of the way.

My wires are very short and I turn the receiver on as I am facing away crouched from the rocket. I use short wires that are heavy gauge(thick aligator jumpers like radio shack sells) because I don't want any voltage drop. The yellow bee will only supply 5 volts to the igniter but that is plenty to light it right up. Normally your handheld launcher uses 6 volts.


The benefits of this are wonderful as far as I'm concerned. I can get back hundreds of feet(probably around a 1000 but I never tried that far) and then use a handheld altitude tracker or just watch it ascend without craning my head back. Also it makes tracking the rocket's descent much easier.

This is a really fun way to launch them and it's perfectly safe as long as you run enough wire between your receiver and the igniter connection point.

Again I recommend the yellow bee because I know for a fact it's radio system is not prone to interference. I don't remember now what band it's on or even if it's AM or FM but I do know it works beautifully. Normally AM radio systems are more prone to interference because they are usually on 27mhz which shares the spectrum with CB radio users,, plus naturally generated broad band radio signals are AM as well. Any radio system that can apply enough power to directly drive a model airplane motor should be able to apply enough voltage and current to light the ignitor.

Oh and this is a really cool way to get far enough away to film your launches to all by yourself.
 
Interestingly enough you don't need any short circuit protection for the speed controller. I have shorted mine out when the ignitor wires became twisted. It survived several applications of full throttle just fine. As a matter of fact all it did was heat up the wires up to the short point of the ignitor to the point where they burnt the tape that seperate them and melted the ignitor wire into the ignitor plug.

By the way, the yellow bee transmitter gives a satisfying chirp when you turn the transmitter on which is cool, plus it has low battery indication.
 
That is really cool! Not expensive or too difficult. Two posts and you bring with you a neat gadget and a pic. Off to a great start! Welcome to the forum.
 
I got my yellow bee from Hobby Lobby NOT the arts and crafts guys. This is the outfit that advertises on DIY's radio control hobbies show. The link to the yellow bee page is:
https://www.hobby-lobby.com/yellowbee.htm It's only 39 dollars right now. I can't express how easy this is to do. Oh by the way,, if you want to you can fly the plane a few times(if it lasts that long) and only use the radio system once you've destroyed the plane :)))) You can get parts for this plane by the way,, if you get hooked on it instead of wanting to use it's guts for your rockets. I gave up on rc planes myself. I was pouring too much money into it without nearly enough entertainment value coming out.
 
This is just another image to show how it sits in relation to the rocket. I don't have it hooked up to an ignitor in this image because it's 10pm and I'm indoors but you get the idea. Notice the antenna lead alligator clipped to the base of the metal launch rod.

If you are very safety conscious you would want to use longer wires than I did. However I had these nice thick alligator leads already made up so I used them by simply cutting off the clips on one end. If you use longer wire you really need to make sure you use thick stuff like 12 or 14 guage or so,, like lamp cord wire else the resistance in the wire will drop your puny 5 volt 'firing signal' down too much. As I said in my first post, there is a on off switch on this unit which I turn on while facing away from the rocket with my transmitter on. Make sure you don't have the trim settings on the transmitter set too high for the throttle else it will turn on the control line to the ignitor before you want it to. My trim is about 1/6th of the way up. You don't want any idling voltage on the control line at all. The throttle will actually apply a variable voltage to the line, I would recommend simply pushing the throttle to full on immediately when you want to fire the rocket and not gradually bring it up. I believe it may be easier on the speed controller,, although I have mentioned that I shorted it out accidentally with no harm whatsoever.

I'll try and post a picture of the internals tomorrow.
So glad I found this forum! Thanks for the welcome!
 
First Welcome to the forum!
Someone has to break the bad news, so I guess I'll step up to the plate.
Just wait until you get your first stray signal launching your model while your hooking up the clips or as you're walking away.
Since R/C has been around for so long don't ya think folks have thought of this scheme before? Many have, , it's been tried and PROVEN an unsafe, sometimes unpredictable practice. Use at your own rick.
Ps: This system doen't meet NAR safery code standard either. Any "accident" with this system will not be covered by your NAR insurance.
Sorry,
 
Micro,
I am not certain that this setup couldn't be made to work safely. If there was a physical cutoff that only closed the circuit AFTER the clips were hooked up, then it couldn't launch while you were hooking it up at least. Perhaps LtSharpe has no NAR insurance. I don't. ;)
 
Bob:
I didn't give this warning, as an opening for a coulda, shoulda, woulda discussion. The fact is the unit as discribed as a wonderful wireless system is UNSAFE for LT. He is placing his hands and face in jeopardy every time he hooks up a motor.
As I mentioned earlier, folks have been trying to come up with a SAFE R/C launch system for a good wihle now, years and years!
I believe someone is acturally selling a sorta system which has also pronen problematic due to stray signals. Stray signals are an increaseing problem with the increase in R/C flyers.
I hope that sometime in the future we CAN have a secure circuit system. At persent i'm told it is only available to the military. I have plans in the drawer for an R/C controled Bomarc clamshell building launcher base I'd love to build:(
 
It is not a "coulda, shoulda, woulda" discussion. Unless I am reading it wrong, the man says that he turns on the receiver from a safe distance AFTER he hooks up the ignitors. I would simply add another switch.

"Once you have attached your clips to the igniter you go back to where the receiver is laying on the ground, TURN YOUR TRANSMITTER ON FIRST(although in my experience this setup is not prone to interference and I have not had a problem either way) and then flip on your receiver's on switch."

Whatever reason you might have for your warning has nothing to do with why I post. I wasn't aware I needed an "opening" to post a response. I disagree that the danger is as dire as you predict. The NAR matter is not a reason to do or not to do anything, as far as I am concerned, if I am not flying with an NAR club. I am not a member, and he does not appear to be either.
 
Actually I'm sure completely safe R/C system could be built. The only real requirement is an encoded signal. Of course this makes the electronics quite a bit more complex and would probably put it out of most home builders skill set.

I don't think the reason we don't see more of them is safety. I just don't think there is a market for them. Wireless is much more expensive. The simple controller above already costs more than most of us would pay. You can build a wired launch controller for half of what that airplane costs.

Edit: Oh yeah the system above isn't safe. I wouldn't launch with this setup unless it had a remote power switch away from the pad. Kinda defeats the purpose.
 
The frequency on the R/C system that was pirated from the Yellowbee is restricted by the FCC for AIRCRAFT USE ONLY.

Any other use is a violation of federal law.

Keep that in mind. There are frequencies available for SURFACE USE ONLY.
 
First those who htink it's dangerous have no clue how it works. You can have as much wire between the receiver and the rocket as you want. You could have the same 15 foot distance as your estes controller if you want. The ON SWITCH is at the RECEIVER end of the setup. It's the same thing as if you used a push button in that regard. IT's just that when you actually fire it you are at a great distance. There is absolutely no safety concern here. Anyone who fails to understand this is either being purposely obtuse or simply being a 'stuck up sticky beak',, shameless monty python quote...

Furthermore the frequency thing is a complete non issue. Stating something like that is akin to the same people who critique other people's post all across the internet for grammar.

Again, and forgive me but I'm gonna use caps.

USE 15 FEET OF WIRE IF YOU WANT TO. ON SWITCH IS AT RECEIVER END!
 
Personally I think estes 15 foot rule is a bit close myself. Especially after reading some posts on EMRR etc in their stories section. My system simply ARMS the unit at the 15 foot distance(or whatever) but you launch it from up to 1000 FEET away. I usually launch from around 3 to 4 hundred feet because I can see the rocket reach apogee comfortably from that distance.

You can add as many switches and interrupts at the receiver end as you want to but it's not necessary. You could even use a terminal block on the receiver enclouse and hook up your control line to that each time you launch. That way the wires aren't even connected when you hook up the ignitor.
 
Don't know much about these frequencies. Don't care a whole lot either. I understood what you were talking about. You could make a wired on switch as long as you wanted. I get it. Doesn't make your system safe however.

Scenario- 15ft on/off switch, r/c launch switch. Rocket ready to go on the pad. on switch is in on position. You walk another 200 ft from pad. Wind whips up knocking pad over. Before you can return to the on/off switch a r/c pilot using same frequency as your launch controller keys up. Your rocket launches into a crowd of people. I realize this is unlikely and if you always launch alone probably not an issue. It does illustrate, however, why launch controllers are supposed to have a dead man switch that you can get to immediately. So if you want to have 200 ft of wire for a on/off switch because you don't want to spend the time and money to use an encrypted signal then be my guest. Kind of defeats to purpose don't you think.
 
First I launch with no one around. It's actually in the middle of a horse(2 horses in 10 acres, they don't mind) pasture. And again, the estes system has the same safety issue if at all. ANYONE could go and pick up your launch controller, put the key in it and push the button while someone is too close, or wind could affect your rocket just as it could mine. That's not an argument against it I'm afraid.

I can't express enough how simple, fun and easy this system is. I suspect a great many people do use a setup similar to this because it's just so much nicer to see your rocket go up from a distance.. like watching the shuttle go up or something. Plus you can track altitude, or film it without anyone else's help.

Oh by the way, if you want a cheap piece of long thick wire, get yourself a cheap extension cord at walmart or something and use that as your hookup.
 
Originally posted by LtSharpe
You can have as much wire between the receiver and the rocket as you want. You could have the same 15 foot distance as your estes controller if you want.


Good point.
I think it's a good idea, and may even make one myself, since I already have the parts here from a busted plane.

But I usually launch by myself in an area where if the nearly impossible happened, noone would get hurt. Anytime I've launched with a crowd, it was at a club launch at which I would use their pads and let the LCO launch the rockets.

This is why I don't see it being an unsafe thing to do. If I were one that launched around people all the time, I may think differently, but I don't.

I've launched several "heads up" rockets by myself, that I would not have launched at a club launch, but that's just my experimental nature, and I always took appropriate safety measures.

I'm glad people like Micro and others point out the safety concerns, because some may not realize them. But I think sometimes, people forget most of us are pretty intelligent adults, and we know what we're doing.

I, for one, don't launch rockets around guys who are flying their R/C planes.

Tim
 
The attached picture is of the insides of the box. You can't see the board too well but it is mounted by means of pc motherboard standoffs. If you use metal standoffs you need to be careful not to short out the circuit traces around the mounting holes. I needed to enlarge mine somewhat beyond the size that was already there. This needs to be done very carefully with a low speed drill so you don't tear the board apart. You could also put a piece of foam rubber under the board and hot glue it all in instead. If you want you could put a red light on the outside of the unit with a bigger switch as well. I am using the on switch from the plane itself.
 
Originally posted by LtSharpe
Furthermore the frequency thing is a complete non issue. Stating something like that is akin to the same people who critique other people's post all across the internet for grammar.

Why is it a non-issue? Saying it is doesn't make it so.

And welcome to TRF!
 
It's a non issue because there are practically no rc plane people in my area, certainly none within my field of operation.

The thing about using air frequencies being illegal and all that is just complete bs because the very planes themselves use ground frequencies themselves!!

Many planes use 27 mhz guys, sorry but that's how it is. There is nothing illegal about it. It's more of a 'gentlemen's agreement' sort of thing that rc cars use 27. I wish I could remember but I think my yellow bee is a 27 mhz system as well which personally made me think it would be prone to cb interference but I have yet to have a problem.

Too many people come up with these silly ideas about what is legal and what isn't simply in an effort to make themselves sound smarter than the rest of us :)

As another poster said, I wouldn't be launching my rockets at an RC event! lol namely because someone might fly into my rocket!
 
LT
We are trying to keep you from hurting yourself and more importantly the hobby.
As Bob mentioned your violating at least one Federal law, ignoring the Model rocket safety code and like it or not being kinda nasty to folks who are only trying to help.
With all the Federal trouble we've had reccently, The Hobby doesn't need a misphap due to ignorance.
Those who are giving you benifit of their knowledge and experence are simple trying to help you have a Happy and Safe launch. As mentioned before, I'd love to have a good way to incorporate R/C into a couple Scale model launchers.
Please take this advice for what it is, Help KEEP the hobby the safest active outdoor sport/hobby bar none. How You personally launch in the privacy of your 10 acre horse farm is entirely up to you. But lets try to remember there are many young and not so young folks here that will try things if they mistakenly believe it is OK. We are a friendly bunch here on TRF, the good of all is were we are coming from. Those who only fly by themselves are missing a very large amont of information and knowledge, Personally I hope you will stick around and look at all there is to share. There is no ill will here, we are not attacking you or your flying, We are trying to give you Good solid, informed information that you do not have.
This is your first post, sorry it hasn't been as positive as we would have liked. It's sometimes hard to get info accross without sounding negative. These Many many problems with R/C controlled launchers is the very reason I attempted to word my first post saying this has in fact been tried many, many times by loads of people. ALL, Every single one HAS experenced SOME mis launch by SOME stray signal regardless of the number, or locaton of the disconnects. You have to activate the reciver at some point. Once it's on your system as shown is a danger, if only to the horses;)
Hay rbeckey: This is exactly what I ment when I said I wasn't trying to open a Coulda, Shoulda, Woulda discussion. SEE!!!!!
LT: I hope this will be the end of this discussion. NO hard feelings, it isn't personal or intended to be hurtful to you.
Sorry if sound advise is taken the wrong way.
I'll not post to this thread again. Hopefully other will do the same.
 
LT

I wasn't trying to be a smart a**. I personally have no problem with you making a remote launch system.

I got the impression from your first post that your radio was on 72 MHZ.

The 72 MHZ band is divided into channels with some reserved for Aircraft and some reserved for Surface use.

The 72 MHZ transmitters are more powerful and have the potential of causing interference up to 3 miles. I say potential because the conditions have to be right.

There is no such restriction for 27 MHZ or 49 MHZ. They can be used for either Aircraft or Cars / Boats. If you want a cheap R/C unit for something like this you can get an R/C car at Walmart for as little as $16.00 on 27 MHZ.

I don't want to cause any hard feelings but I am an R/C flyer also and have had crashes due to interferece.
 
lets not compare model rockets to r/c aircraft, you can turn off an r/c plane ..you can't turn off a rocket .so saftey issues differ between the two hobbies concerning the use of remote controll devices. I can't find a link to clarify this right now.but I definately have read issues concerning this ( i want to say Faa ruling, but I don't have time to look right now ...at work).

I have no personel opinion either way,if infact there is no law against it
 
Micro I'm not angry, I am frustrated though because I don't think you understand how this works. See my new thread in the forum with an image of the setup outside. Once again, you ARM the unit at the RECEIVER END. There is no possiblity of it prematurly going off(With anyone at the rocket) any more than your estes launch controller prematurely going off(ie internal mechanical malfunction or some kid picks it up and says, whats this!). In the new pic I posted you will see around 12 foot of wire or more between where you arm it and the rocket. This is not any different than normally launching the system. Except that when you actually fire it you are hundreds of feet away, to me this is a very cool aspect and allows me to track height, film it etc(and prevent neck cramps)

I also do not believe for a moment that any law is being broken. That's just complete nonsense. It MAY violate an NAR rule but frankly I don't care. I don't belong and have no interest in belonging. There aren't even any nar launches within 250 miles of me.

By the way the high power guys often use an rc system as a backup for their ejection charge. NOW THAT is dangerous because they can't remotely arm the device, think on it and you'll see what I mean.
 
Sure but to me that's a bit of a hassle having to run the wire all the way back to where I want to stand,, if I'm only launching no more than 3 times. This is a very quick setup kind of thing. Plus with this I can move around however I want quickly and easily,, say to change the launch pad's position due to wind etc. I often will launch in various locations within the same launch session due to wind direction. I don't want it to come down in the neighbor's cow pasture.. stampede! or simply,,,, 'SNUFFLE,,,, STOMP!'

The only safety issue is that you have to remember to turn OFF THE ARMING switch when you go back up to the rocket after you have launched. This is akin to putting the estes launch key and rod cap back on the launch rod after each launch(that used to be in their manuals I don't know if it is nowadays).
 
Originally posted by LtSharpe
Micro I'm not angry, I am frustrated though because I don't think you understand how this works. See my new thread in the forum with an image of the setup outside. Once again, you ARM the unit at the RECEIVER END. There is no possiblity of it prematurly going off(With anyone at the rocket) any more than your estes launch controller prematurely going off(ie internal mechanical malfunction or some kid picks it up and says, whats this!). In the new pic I posted you will see around 12 foot of wire or more between where you arm it and the rocket. This is not any different than normally launching the system. Except that when you actually fire it you are hundreds of feet away, to me this is a very cool aspect and allows me to track height, film it etc(and prevent neck cramps)

Just because someone doesn't agree with you, that doesn't mean that they don't understand what you're saying. I'm sure, beyond any doubt whatsoever, that Micromeister understands exactly how your system works.


Originally posted by LtSharpe
By the way the high power guys often use an rc system as a backup for their ejection charge. NOW THAT is dangerous because they can't remotely arm the device, think on it and you'll see what I mean.

Do you have any links or anything to back that up? I believe I have seen mention of radio backup for recovery system ejection, but "often"? I'm not too sure about that.

I hope you don't think that you're being attacked personally, because you aren't. People are extremely concerned with safety, since model rocketry has been very safe since the very beginning in 1957. Also, the current political climate makes people very sensitive to anything that might be seen to be a possible danger to the public. Your system is probably pretty safe. But it is not, and can't be, as safe as a hardwired system.
 
The reason I said he did not understand the system is because he stated it's my fingers. My fingers aren't a problem since the thing isn't even armed,, just like your launch key is not even in the controller.

The only problem and I will certainly admit this is,, is that unlike the controller where you have to put in the key and push a spring loaded auto release button is that once this is armed it's armed. It will still be armed when you walk up to the pad which is why you MUST turn it off so you don't start to wire up another rocket while it is still on.

That is the one and only safety issue. You granted have to push the throttle on the remote to actually fire it but you are prone to interference, and that's the wildcard. But again, ONLY if you forget to turn if off. There are several ways around this. One have a big light on the box that is on when the receiver is on. Or two, have a set of interconnects that you ALSO have to connect before the system fires.

You can actually get even more sophisticated than this by using delay circuits and relays etc etc etc the sky's the limit,, but my system is simple and uncomplicated. It's like with anything there is always room for user error in nearly anything. Think of all the ways you can kill someone or yourself driving a car 70 miles an hour down the interstate?
 
Oh and about the ejection thing. On the discovery channel rocket series they actually had an example of ejection charge circuits going bad... The guy is on a ladder along side a high power rocket working with the nose cone or something. In the foreground another team member is being interviewed. Some guy at the bottom hooked up the power and the charge prematurely went off, blowing him clear away from the rocket off the ladder. The look on the interviewed teammembers face as the thing goes off behind him is priceless,, he was scared sh1less as can be imagined.. Fortunately they had emts there and the guy was ok, just badly frightened.
 
Originally posted by LtSharpe
Oh and about the ejection thing. On the discovery channel rocket series they actually had an example of ejection charge circuits going bad... The guy is on a ladder along side a high power rocket working with the nose cone or something. In the foreground another team member is being interviewed. Some guy at the bottom hooked up the power and the charge prematurely went off, blowing him clear away from the rocket off the ladder. The look on the interviewed teammembers face as the thing goes off behind him is priceless,, he was scared sh1less as can be imagined.. Fortunately they had emts there and the guy was ok, just badly frightened.

I know second hand that recovery systems sometimes fail to eject in HPR, or that they eject when they aren't supposed to. What you stated in your earlier post, though, was that radio-controlled systems are "often" used in HPR. So I asked if you could direct me to someplace that documents that.
 
Not to fall into habit of picking nits but I'll bite :) I got this impression from a high power rocketry forum I used to read on the net. I don't know the link anymore. If I come across it I'll post it,, but debating whether or not they do this was not my point.
 
Back
Top