I'm just getting into pyro, but I would appreciate some help. First, off, I'm wondering about fuses. What is a simple way to make a fuse? Second, the only time delay I can think of (that I would know how to do) is taping a lit cigarette to a fuse. But that is unreliable. I'd like to learn how to make a time delay with an oven timer or something like that. Or, learn how to wire one to a cell phone, to go off when the number was dialed. And I'm just talking about smokeless gunpowder, I havn't got into the more complicated things.

Fuses suck. Go with electrical ignition (http://godlovesmeat.com/spatulatzar/igniters/).

Yes, what she said. But if you insist on fuse, use a sparkler if you can't get commercial fuse. Even sparklers I trust more than homemade fuse. Here we have metal sticks with grey sparkler composition on them, you can wrap those types tightly in a couple layers of Al foil to make them burn under water and with few sparks.

Cell phone detonator? Open it up, there should be an unbalanced motor responsible for the vibrate function. Clip the two wires from that, and hook it up to some Nichrome wire. Set the phone to vibrate upon receiving call, and make sure nobody else calls that number. I've never done this, or even looked inside a cell phone, I'm just suggesting what others have told me.

Reliable fuses are very easy to make at home... but not with smokeless powder.

being the spatula tzar supporter that i am..
http://img524.imageshack.us/img524/4237/img1620vf9.jpg

did i mention it works like a charm? a charm²

although, using just a regular RC-servo detonator is easier, and less hassel (when you dont feel like setting shit up), but it is definatly less safe.

btw, for a power source, i would strongly recommend buying a laptop battery on ebay. they work great, and are compact.
Small strands of that wire you use for hanging paintings that you can buy in home depot work really good too.

ChainHit i would love to discuss whatcha got there a bit more in detail if you have a min or 2 do you have a way i could contact you ?

Thanks alot. Every post has been extremely helpful. I never thought to use a sparkler (not that I'm going to use that now that I have the informations you guys provided). I read how to make fuses, but it was extremely complicated, as was making alternatives to gunpowder.

Wireless rig looks like a fun project thou i dunno i hate working with PIC's but what the hell i shall give it a shot see if i can imporve on the code and a few other feature thou i must say it was designed fairly well

Warweed, I have lots of ideas for improvement, so contact me before starting. Among them is a way to improve safety, eliminate an IC, lower the operating voltage, make the whole thing much smaller and cheaper, and add a high voltage ignition power source.

ACE, beware sparklers as fuse. They may burn slowly and reliably, but they throw lots of hot sparks, capable of igniting things prematurely. If you can't find anything else, open up a few roman candles for some cheap visco.

Eliminate the PIC ? why ? that would leave some form of logic programming ... which is a bitch x2 jus trust me on that ... i think some way to open the line with out having to keep it open would be a added benifit .. this way in chain's renderation the line does not have to be open while arming... simply call and it auto anwsers and then you can dump your password.... i would also look into possibly Into MF rather then DTMF just because... as any phreak knows there are possibilitys althou remote that certain sounds could cause a problem .... i can whistle 'some' DTMF so yeah

other features would be battery indicator ... capacitor charge indicator... led indicator showing charge is connected and there is no short in the squib .....

honestly thou there are no a WHOLE lot of improvments you can make other then maybe include multiple passwords for multiple charges ...

I never said eliminate the PIC (although Atmel might be easier to work with). With some fancy programming, the DTMF decoding can be done on the microcontroller, eliminating the separate decoder. This also eliminates the bulky external crystal.

Without the 8870 chip, it can be powered with three volts instead of five, eliminating the 7805 regulator, and saving lots of power. AA batteries are also much cheaper than 9Vs.

If a high voltage ignition system is included, the bulky relay can be eliminated, making the whole thing solid state. It's probably not much of a danger, but the relay can be falsely triggered by whacking it.

Another feature is feedback. It's a two way audio channel, so the microcontroller can easily play tones back to the user.

Remember, chainhit's remote is entirely my design. It doesn't need to keep the channel open. The controller only cares about the tones, not the connection. I know some things can mimic DTMF tones, which is why it has a password. It can be as long as you like, making the odds of accidental activation with random dialing very low. I chose DTMF because the telephone is a convenient and familiar encoder. You could just as easily set up a second device to transmit a very long stream of random bits as a password. DTMF was made for a reason. I think it's definitely the way to go.

So, who wants to help me?

Cell phone detonator? Open it up, there should be an unbalanced motor responsible for the vibrate function. Clip the two wires from that, and hook it up to some Nichrome wire. Set the phone to vibrate upon receiving call, and make sure nobody else calls that number. I've never done this, or even looked inside a cell phone, I'm just suggesting what others have told me.


Yes the vibration action is produced by a motor with a one sided cylindrical weight attached to the spindle but there are NO brakes watchsoever on the motor. So if the phone gets shuck, or disturbed, it may complete the circuit prematurely.

This youtuber/ metacafe guy is a charlatan:

http://ie.youtube.com/watch?v=WPue9Kc4owE

Anyways the motor is usually only supplied with a max 1.5V and a very small current for a brief amount of time (the vibrator action in most phones is usually turned on and off rather quickly)... so it's not exactly going to cause the nichrome wire to do anything with such a small amount of current going through it for such a short amount of time.

Anyways the motor is usually only supplied with a max 1.5V and a very small current for a brief amount of time (the vibrator action in most phones is usually turned on and off rather quickly)... so it's not exactly going to cause the nichrome wire to do anything with such a small amount of current going through it for such a short amount of time.

In comes a permanent relay ... hmm, whats the proper English term for a relay that doesn't break circuit after the first current is removed?

http://en.wikipedia.org/wiki/Pyrotechnic_fastener
Manganese/barium chromate/lead chromate: time delay mix, used for sequencing. Gasless burning.
RDX/nitrocellulose: gas generator, unsuitable for deep space missions, burn rate dependent on pressure.
Boron/potassium nitrate: gas generator and rocket motor igniter, thermally stable, stable in vacuum, burn rate independent on pressure.
Zirconium/potassium perchlorate: NASA standard initiator (NSI). Rapid pressure rise, little gas but emits hot particles, thermally stable, vacuum stable, long shelf life. Sensitive to static electricity.

NASA has some fun stuff.

In comes a permanent relay ... hmm, whats the proper English term for a relay that doesn't break circuit after the first current is removed?

Latching relay. Typically they have a rotating mechanism to switch on and switch off with single pulses. X10 controllers use them.

Any relay can be configured to latch and stay on with a single pulse. Simply have the normally open contacts provide power to the coil. Of course, it's a very bad idea to use a cell phone ringer as the trigger.

A much more elegant solution would be to program the phone to listen for the password and have it activate one of the I/O pins. It would be just about perfect, if the manufacturers would ever let you write your own programs for their phones. You'd have to rewrite it for every model too. Before you ask, I wouldn't trust a "smart" phone with this. They're extremely buggy, and likely to kill you without warning.