47 replies to this topic

[nickpatts]

sequencers i have no problem with because in a way they have a use in pyrotechnics and can produce some nice timed effects,but when it comes down to delay timers,remote det ect, its leading to a more sinister "device" no real use in pyro in my opinion,somewhat bordering on the "kewl bomber" kid type stuff ect. Keep it clean and safe and on topic, big brother is watching...

Edited by nickpatts, 31 August 2003 - 11:49 AM.

[Pyromaster2003]

maybe for soem people but its the only real way i can light a charge because of the area i live in...full of people and houses. if i want to light a flash bang i have to use 4 inch of fuse and hide in a bloody tree for 5 minutes after its goen of incase anyone sees me and reports seeing me and hearing a loud bang, with all the houses around the noise echos all over the place. my dream is to live in the country preferably 10 miles away near Adam:)(not like i fancy him or out lol, hes the closest pro pyro to me)

[Gor]

Even out here in the country you have to be a bit careful, its fine for a quickie, but for lasting satisfaction you need to find the right spot.

Why not get a bike?

[Pyromaster2003]

where abouts are you Gor? i do have a bike, but i dont realy want to ride 10 miles to the country with a load of fireworks on my back. it shoudl all schange in 1.4 years (cant wait:)counting the days) because im getting driving lesson on my 17th birthday and il simply drive up to the country and find me a place to light it all.

[OxCid]

yeah nick, i get your point and that was why i was unsure whether to write about it. i will try to concentrate more on sequencers but i still feel some legit pyro's may want to try remote ignision and also people may prefer to use it if they want to do some SFX and dont want wires trailing.

[Pyromaster2003]

i got my very very crude design up and running great now. it enables me to follow a rocket up now instead of using loads of fuse. it works the same as electric igniton by attaching the 2 wires from speaker wire to a bettery and the nichrome wire heating up... however this device is slightly different, i already have 1 wire connected to the - end of the battery and the other wire is 5 mm away from the + end, i used a reciever and servo from my electric place to move the 2nd wire onto the + connection which creates the full circuit n hthe wire glows and lights the device.

[mrpyromx]

thats a good idea pyromaster, I want to make just a 20 que box using 12 volt relays, but its now just figuring out how to hook the wireless part up to 20 seperate relays, it would also be nice to figure out whats what on the lpt1 port of my computer and make it all computer controled. weather it be manual or automaticly fired.

[OxCid]

for the igniters i have used in the past i have used small lightbulbs as they require far less current to glow red hot, i was wondering if anyone knows what voltage/current estes rocket igniters require?

[mrpyromx]

my last model rocket i have only took 2 double a's in the little launcher. so that was only 3 volts.

[Pyromaster2003]

i have pics of my horrible looking contraption which im pretty ashamed of on my website under 'my pictures' so if you feal the urge to see what a load of crap it is, feal free to take a look.

[Stuart]

I use steel wool for my electric igniters. 9V wont do though unless its REALY thin. I use 12V from a lead acid battery. Not a car one, just a small one. (About 2cm deep, 10cm high and 15cm in width). When I get my firing box up and running then electrical detonation will be what I use all the time.

Stuart

[adamw]

NOTE REGARDING ELECTRICAL INITIATION:

Please all be VERY careful when using remote means of initiation. Many accidents have happened using such means. Always make sure the supply is isolated at the battery! Make sure nobody else is around the battery / firing box when you are connecting the device. Only ever allow someone you trust with your LIFE to tell you that the supply is isolated, otherwise, check it yourself and be reassured that anything nasty can't happen. I like to 'shunt' the connecting wires before wiring up a device. Shunting is touching the two leads together for a second or two, causing a short which will dissipate any residual current/static in the line. If you are using a battery to fire, if you shunt the wires before connecting your device and get a spark, you know you have left the battery connected and you should feel very scared for yourself!

Radio control can also be dangerous. Using a RC controller and servo isn't very secure, so if anyone is flying a RC plane in the area, there is a chance that they could set your device of prematurely. I use a 69 bit secure system with code hopping protocol (32-bit hopping code generated by a non-linear encryption algorithm, with a 28/32-bit serial number and 5 data bits to create up to a 69-bit transmission stream), which means there is a 1 in 256,000,000,000,000,000,000 chance of someone else accidentally setting the system off.

I also use a 256 channel computer automated firing system, which is quite tasty. Even using that you cant ignore the basic safety when dealing with electrical firing.

[RegimentalPyro]

OK - Not knocking adamw's firing system, but the main thing to focus on with RC firing should be the authentication protocol.

That 32 bit hopping algorithm better have the "RSA" label on it for it to be secure, and let's not forget the fact that you are transmitting your serial number with every firing pulse.

AdamW is quite correct when he says there is an infitesimal chance of someone setting off something accidentally.

BUT!

there is actually a fairly good chance that this system would be open to a malicious attack - If anybody is interested I can outline how. Running a wire is ALWAYS safer. Use RC with extreme caution.

[yanhua]

The whole concept of code hopping means it is very hard to capture the code and resend it, part of the code is random data (32 bits to be precise).

The protocol is part of a very high security system.

Running wire is more prone to attack.

Yanhua

[RegimentalPyro]

Lets make some assumptions about how this systems works.

What happens if the firing box sends out a firing pulse which doesn't get through to the listening box [electrical noise/distance/gremlins etc]. At that point the firing box would be out of sequence with the listener and the display would be locked out until someone physically resequenced the firing/listening box.

What usually happens with these systems is that the listener will actually accept a range of codes. say the next 8 or previous 8. This would get round the problem but you are then down to 28 bits, or a one in 268 million chance.

My computer can count up to 268million in seconds.Even if the listener is the more secure version that will only accept the next code in the sequence it would only take minutes.....

You could make this a lot safer by setting the listener to shut down if it receives a lot of out-of-sequence signals, but this means that someone could shutdown your display remotely just by pressing a button.