Remote Control

Wondering if anyone has ever built a simple remote control ignition system. This would be really simple to do. Just hook a make or break
connection between a battery and the wires going to your igniter across a mechanical servo and when it moves the wires together, whoosh. The servo could be any cheap airplane type with a cheap receiver on it. Then you could trigger your rocket from say 1000 feet away or something and see it go skyward. I've been wanting to do this. One caveat is that the receiver should be FM and NOT on 27 mhz so to be more immune to interference and likewise you should have the battery connection point at least 15 feet away as with a normal estes controller launch. That way if the servo prematurely fires you aren't too close to the thing when it goes off. I'd love to do this so I could get good video of my stuff going up by using a tripod etc and the video camera. I could just reach over and push the 'throttle' control on a model airplane transmitter and away it goes!!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dan;
like this:
http://www.aeroconsystems.com/electronics/radiofire.htm
shockie B)

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
shockwaveriderz wrote:

Their idea seems to use it for manual override if you ejection system doesn't work etc They don't seem to think it can handle enough current for a main engine ignition except I think they are referring to 'really' big rockets not small estes stuff so it would probably work fine. I've got to figure out how much current a typical solar igniter requires,, I might have a receiver that I could just tie directly to one of them isntead of using the mechanical servo as a switch.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Wondering if anyone has ever built a simple remote control ignition system. This would be really simple to do. Just hook a make or break connection between a battery and the wires going to your igniter across a mechanical servo and when it moves the wires together, whoosh. The servo could be any cheap airplane type with a cheap receiver on it. Then you could trigger your rocket from say 1000 feet away or something and see it go skyward. I've been wanting to do this. One caveat is that the receiver should be FM and NOT on 27 mhz so to be more immune to interference and likewise you should have the battery connection point at least 15 feet away as with a normal estes controller launch. That way if the servo prematurely fires you aren't too close to the thing when it goes off. I'd love to do this so I could get good video of my stuff going up by using a tripod etc and the video camera. I could just reach over and push the 'throttle' control on a model airplane transmitter and away it goes!! <<<<<<
You could not do it from 1000 feet away, since the ground range probably would not be that good. Yes, model planes fly farther than 1000 feet without going out of control, but radio range in the air is a lot better. When closer to the ground the reception is poorer, and when on the ground, even worse.
And that leads to the other issue, since it would be a ground system, you really ought to use 75 MHz which is for surface use, like R/C cars and boats. Pretty much, if it flies, its 72 mHz (Air) , it its on the ground, its 75 mHz (surface). So in this case since the launcher is on the ground (and the device being controlled), that makes it 75 mHz (surface band).
Of course whenyou said 1000 feet, you probably didnt mean you really had to go 1000 feet. You could test out to see what is a good reliable max range for a surface R/C system then get significantly closer than the max range so you would have some safety cushion for the range.
You can improve the range by using some non-metallic rod or dowel to hold the receiver antenna straight up, and to ideally hold the receiver and antenna off of the ground somewhat.
Rather than having the servo cause two bare wires to touch, use roller or lever switches, mounted in such a way to cause the servo to press them closed. A large diameter round servo output arm with a pie-shaped notch cut out of it works well for this sort of thing.
Also note that if there was any glitching and the servo happened to move to the trigger position on its own, it would of course fire. To reduce the odds of an accidental firing, you could use two servos on two channels, and wire the switches in series so both had to trigger to cause ignition. So youd need to trigger both servos to the right position using the transmitter.
Other tips, turn on the transmitter FIRST, then the receiver, and as you noted, arm the ignition system last (from that launch battery you mentioned being 15 feet or more away).
Having said the above, Ive not remotely ignited a model on the ground by using R/C, but for awhile used a relay system and 100 feet or wire to launch R/C Rocket Boosted Gliders myself. 2 years ago, I got a wireless remote system thats no longer sold, which uses a garage door type transmitter and receiver system. So no more messing around with laying out the relay wire. The system was wired up so pressing one button armed the receiver for 5 seconds and a second button would ignite the model unless 5 seconds elapsed. Works pretty nicely, though the range is only 150-200 feet (supposed to be about 300 feet but real-world was different).
In any case it is indeed nice to be back far enough from a model to see the flight path more from the side than looking nearly straight up when launching from 15-20 feet away.
- George Gassaway
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not sure if you're talking about ground support equipment or RC firing of a second stage. Both have been done.
The neatest RC launch system I ever saw is one NCR prototyped just before they got assimilated by Estes. It used off the shelf 12v car alarm electronics. The TX is already well encoded to prevent false triggering. And the base unit is designed to work on the same 12V power we have on the rocket field. Range certainly wasn't 1000', but was probably a good 50'.
As to RC ignition, John Kallend's LadyHawk is a 2 motor model. He fires the first one on the ground via a normal launcher to boost the model, then ignites the second motor while gliding for more boost, or perhaps a powered loop. IIRC he does use the throttle function for this, but I think he's got electronics rather than a servo pushing a firing button.
Folks have also done RC ejection, both for scale models and HPR. Someone (was it Doug Pratt?) used to sell a system for this purpose.
But as others have said, realize that our rockets can fly a LOT higher and/or farther than conventional RC systems are work at.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
Save Model Rocketry from the HSA! http://www.space-rockets.com/congress.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I was working on designing a remote car starter into a launch controller. Didn't finish though. I wanted to use the starting feature for ignition, but the darn thing is looking for too many different input signals for me to fool. But I could have just used the power door locks to trigger launch relays, and it's supposed to operate from distances of 1200 to 1500 feet. I know that the starter in my car will operate from a distance of a full city block.
Kevin Rezac
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

"city block" = 660' Still, that's probably enough range for most of us.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
Save Model Rocketry from the HSA! http://www.space-rockets.com/congress.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bob Kaplow wrote:

I'm very glad that there are people who can point out to us how far a city block actually is. It helps me to sleep easier at night :)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.