THE Remote actuator.
One of the best methods of being safe when something bad happens is not to be there when it does.
Yes, remote activation is the safest means of testing your devices, launching rockets, lighting the BBQ or just inpressing your friends on the 4th. This article is instructions on how to build you own device for safely activating things at a distance.
There are numerous articles on how to build a rocket Ignition control. This one is different because it has a few other features for both power and safety.
* First due to the battery being located down range you get more power to the igniter or other device than if you use long wires. This device can supply 12v at 25 amps for quite a while depending on the size of battery.
* Second, you will notice that the fire relay is connected in such a way as the igniter is shorted unless the fire button is pressed. This is a best practice whenever low current igniters are used.
* The use of indicator lights to show progress of each step.
* The addition of a arming output so you can power other things before the fire output is turned on, like a nitrous oxide fill before the ignition of a hybrid motor.
* Notice there is no continuity signal on the output. This is done on purpose, you check the continuity with a VOM meter before connecting the out put to the control. This is the proper method with single fire controls.
* This design will handle 300 feet of cable. I recommend 20 gauge alarm wire preferably stranded. The plug can be whatever you find lying around, I used 4 conductor microphone jacks.
So what is the advantage of a remote firing system over just a fuse or a long wire and a battery? When you play with dangerous toys its best to be Safe and professional.
Safe because you want to be doing this for a long wile.
Professional because you want people in authority to think that you know what your doing.
Shopping, I personally think the best place to shop is the junk yard or online surplus. If you can’t do that route I would make a visit to RatShack.
I use ammo cans as the box of choice for my ignition control systems. It keeps everything nice and rugged and looks official. The hand control box I bought at RatShack.
The cable I got from a dumpster (300’) All totaled I think I have a total of maybe $20.00 invested. Its not pretty but it is one reliable and sturdy design.
If you can’t read the attached wiring diagram you really shouldn’t build this device.
All connections should be either soldered or crimped. I use solder on everything except the relay connections, they use 1/4″ quick connectors. All wire should be a minimum of 18 gauge except for wires going to the relay coils, they can me as light at 22 gauge. The battery should be as big as you can get in an ammo can. The ones I use are originally used for emergency lighting, they are available at most construction sites during a major renovation.
If you have any troubles and your serious please contact me. I can either help you or maybe if your real nice I will make one for you. But it won’t be nearly as cheap or satisfying if you make it on your own.
I have probably made a dozen launch controls, some with 16 channels, some with remote continuity, and all kinds of bells and whistles. The one pictured here is simple and strait forward, it is almost a must to bring to any rocket launch or pyro shoot.
You never know when your neighbor decides to light his BBQ with gasoline. Now you can stop him before he says “He yall watch this” once connected to your new controller you can say “I’d do that if I were you” with confidence.
The next step is to make the igniter.
Ok here is my disclaimer.
Don’t make these if your not completely comfortable with mixing chemicals and proper safety practices. Pyrotechnic compositions are nothing to fool around with and you can seriously injure yourself or others. When in doubt don’t. But if your reading this, your already doing things that you probably shouldn’t so I guess your just going to ignore me anyway. Just try to remember these precautions.
Don’t smoke, Acetone is flammable, even with no chemicals mixed into it. Acetone stinks, make this outside if you can. Keep away from open flames, this means the water heater and furnace. Measure everything using the most accurate scale you can find. +/- .1 gram is ok. Powdered metals are hazardous, don’t get any that is less than 200 mesh. Don’t get magnesium near water.
The reason I am posting this is not to encourage anyone to use this in a way that is in anyway unlawful, but because I know you and you will find a way to light your gadget, I am simply showing a way that is less dangerous to you and others.
Making your own igniters.
First of all why make your own igniter? Well, only necessary if you really want something to burn when you want it to burn. A fuse is nice but once lit your kind of committed, matches, flaming paper, punks all pale in comparison to electric activation.
Now there are some of you out there that still use the solar igniters that you get with Estes motors to electrically ignite things. These are fine for black powder motors. But that’s it. They are fragile, hydroscopic, and don’t create flames and sparks needed to really be sure if ignition. Aerotech sells first fire igniters, and they are just fine for a small rocket motor, say a G80 or a H123. But if you want that K777 to light the first time, or your Wimpy Red formula to leap of the pad then you need a manly igniter.
To make things simple an electric igniter is basically a little heater with some flammable chemical attached to produce a flame. As a bonus it should be water proof and rugged.
The best wire to use is Nichrome wire. I use what other people throw away. Each piece of Thermolite comes with five strands of nichrome wire. You can get your own nichrome wire and all the chemicals needed here.
Prairieflounder’s two keys to a manly igniter.
First a good electrical connection to the resistance wire.
- First strip the wire like in step (A)
- Then Wrap the nichrome wire around the tip like in figure (B)
- Then loosely wrap the nichrome wire around the insulated wire like and then the stripped bottom conductor like in (C)
- Lastly solder both connections. (D)
Next a good pyrogen is needed. What you want is for the nichrome wire to heat up quickly from the electrical resistance, then the Pyrogen ignites. The pyrogen should have enough metal content to burn fiercely and throw hot burning molten sparks. This is the key to lighting anything. If made correctly these igniters will light mud.
The Pyrogen should meet all these qualities.
It should be easy to apply to the wire.
It should be slightly flexible or at least strong enough not to break with abuse.
It should be easy to light but not dangerous to handle.
It should be reasonably waterproof, nothing worse than a water soluble solution making pyromud in your range box.
There are a lot of formulas out there for igniters. I don’t pride myself on having the best formula out there, but it is a good formula and has been not only tested but verified with remarks like:
WOW I have never seen a Green Gorilla light that fast!
That igniter probably added 100’ to the altitude!
If this igniter doesn’t light a wet cactus you get your money back.
Anyway here is the formula:
Measured in Parts by weight. If you make this in grams you will end up with 100 grams of extremely flammable material. Oh don’t mix dry. It’s not especially hazardous but why take chances? It is stable when wet, but still extremely flammable.
Potassium perchlorate 53
Strontium nitrate 25
Red gum 10
Magnesium 200 mesh 5
Copper Oxide 2
Aluminum spherical 200 mesh 10
Mix the metals and binder first. Then mix with enough acetone to dissolve the parlon. Then add the oxidizer and add more acetone to make the mixture like mud. It should be sticky. Once it’s the consistency of pudding dip your wire igniter into the mix. It should have a nice coating over the wire. Dip as many igniters as you can make. You can re-activate the formula by adding acetone but it’s a bitch to stir, so make ‘em while it lasts. Double dip ones that are drying if you need extra large ones.
Wait a few days for the mix to thoroughly dry and try one out. Should light just fine off a 9v battery or a nicely constructed IDTIIWY ignition box.