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Making ignitors


Guest Mark_the_pyro

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Guest Mark_the_pyro

Does anyone know the composition for making electric ignitors? I know everything else, but its just the comp.

Thanks

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Are you talking bridgeless, or bridged? For bridged ignitors straight BP works fine. Might want to add some metals to heat up the flame/add sparks

 

Bridgeless:

 

Go here: http://www.frogfot.com/pyro.html#elig Frogfot has an excellent article on how to make bridgless ignitors. They are near the bottom of the electrical ignition section.

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Bridged is where there is a thin wire that emitts heat connected to the two wires leading from the battery. Brigeless is where the two wires are directly covered in a composition without a wire connecting the wires. Obvitously you didn't look at the link because there were pictures.
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If you don't have access to thin NiCr alloy wire, you can also use steel wool. That is how I made my extremely ghetto ignitors. I didn't even try to coat it with a primer comp, just the steel. Construction was very dodgy, basically just twist a braid of steel wire and stick it in the mesh of wires at + and - terminals. They worked 85% of the time.

 

Bridged with NiCr wire isn't too hard, though if you solder them, it can be somewhat labor intesive. It really just depends on your soldering skills.

 

Bridgeless consists of graphite and NC solution. Easy enough. Simply dip and dry, coat with meal/metal slurry if you want to prime

 

Fairly painless, and pressing a button and fractions of a second later, your match/device firing is quite satisfying.

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Have any of you people tried nitrocelluloce +graphite electric ignitors composition ?

i want to know if it works fine and dont do any problems before i use it

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I'm being modest when I say I'm alright with soldering yet I can't manage to get nichrome to solder to standard tinned wire. Is it just me?

 

I'm gonna try the christmas light method. I scored 200 lights for NZ$2.00 two days after xmas. That included a 25V 1A transformer and about 8m of extra cable. Might I add it also has 10 spare bulbs. And at prices this crazy cheap it pays to metion that the spare bulbs came in a little resealable plastic bag. And the mains plug wasn't even mold sealed! Those plugs about $8 themselves alone.

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I wouldn't mess around with soldering. Christmas light method works awesome if you have a belt sander with high grit paper on it then you can mass produce them and store them and put a little Black Powder in there before you use them or what I do is make a Black Powder solution and dip the tips in them and let them all dry then I won't have to mess with them anymore when you pull them out.

Anyone that has done this will know that it is a time saver.

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Yeah, I have a roll of christmas lights that I scored from a scrap place. I totally forgot about those...

 

The NC/graphite has been used by at least 2 very reputable people. Some other conductive carbon(lampblack) could also be used IIRC. I would be interested to see how they work for you.

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Ahhh high grit sandpaper might be the problem to all my woes! I keep trying to grind the ends of with a two stone grinder. It works well while you are still grinding the concave tip but as soon as you hit the cylindrical glass it smashes into lots of little pieces. I'm guessing because of the vibrations from low grit stone.

 

A disadvantage of xmas light ignitors is that they are quite large. I can't see how you could fit them into a fuse hole. Meaning you would have to use a combination of fuse and bulb to light to device. More safe, but I really like the idea of push and boom! Gives you more satisfaction.

 

I tried my hand a some bulb ignitors last night. I did my best to retain at least half the glass and snipped most sharp edges of with wire snips. Then I poured some black powder in and sealed with NGBP. My first one didn't work (I think I broke the wire), the second one exploded! As soon as I hooked up 12V it went boom! NGBP must of held in gases and caused glass rupture. And I wasn't wearing glasses.

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For soldering nichrome, you *must* use ruby fluid flux, no other type will work properly. Sand the ends of all wires with 200+ grit emery paper, dip each one in the ruby fluid, then solder. I've never had good results unless I did this, but it always worked if I did.

 

M

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Using low grit or stones won't make it burst from vibration. It's from taking off too much at a time at high speeds, glass cant take that. Thats why you use low grit.
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It may be the bumps / taking off 'big' chunks, but it might also be the heat that cracks it. I usually only take of the curved part until there is a hole big enough to fill through. If I get to the cylindrical part they crack all the time.

 

Try fine sandpaper (wetted) flat on a table. Not as fast but much less wasted bulbs. You could also use this to finish them, after grinding most stuff away with the machine.

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if you have an angle grinder what you could do is.

Go to a hardware store and get a grinding disc and glue some sand paper to the side of it where you can touch the light bulb to. This will work good just make sure when you put the sand paper on there that its flat on there.

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Yeah, I have a roll of christmas lights that I scored from a scrap place. I totally forgot about those...

 

The NC/graphite has been used by at least 2 very reputable people. Some other conductive carbon(lampblack) could also be used IIRC. I would be interested to see how they work for you.

Christmas lights work wonderfully. I've found that the easiest method is to score the tube with a triangle file, and simply snap the end off with my fingers along the score-line. You're left with a hollow glass tube protecting the bridge wire, which you can fill with BP/NC slurry or a hotter mix like KClO3/Sb2S3.

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"... xmas light ignitors is that they are quite large"

"... and simply snap the end off with my fingers"

 

How monster-big are your bulbs? Mine are 3.5mm dia x 4mm long, with AWG-30 cables heat-shrinked to the glass at the bottom. A little flimsy, but easy to get into cap bodies, or rocket nozzles for that matter.

 

They were cut from a string of *240 bulbs*, wired in series with 4 colours in parallel. Makes 3.8V per bulb, but they glow from one AA cell. I usually take a 9V block battery though, instant ignition. If it has to be *really* fast, e.g. for simultaneous firing of opposed charges, you should see how they take 1500 Volts! :D

 

An Ohm-meter is a must after re-sealing. You dont want to hook up a show to find you damaged some filaments filling them! :P

 

BTW is flash conductive, or is there too much perc keeping the alu particles from touching? And how much voltage does that carbon mix need?

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  • 1 month later...
If you use wire instead of xmas lights on your ignitor what wire can you use that wont burn out after each shot? becasue replacing them takes a while. i use thin bits from the insides of multistrand wire
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I've been experimenting a lot with E-matches recently. The method that I have settled on is cutting lengths of thin speaker wire, and bridging them with the metal piece from a twist tie. Only one can be fired at a time from a car battery, and it takes a a step down from a big gauge wire to the speaker wire for it to work. Meaning that I have some electrical house wiring coming off of my battery which steps down to the thinner speaker wire.

 

Bridging with the thin metal piece from a twist tie has a slight delay, but it is easier than messing around with the christmas light bulbs.

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For real i just use a estes rocket ignition pad and fine steel wool. It works sometimes about say 85% of the time. Somtimes the clips fall off the steel wool or there is too much steel wool and not enough electricity to get it red hot. Other than those two it usually works.
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I tried my method last night on 6 shells, and it worked perfectly. The delay wasn't noticeable, and there were no problems.
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On my ignitors now i just get a really thin piece of wire and wrap it around a small lenght of visco then i place it in what ever i want to set of works really good, also rechargable AA have loads of Current so they can through a really long lengths of wire on my ignitor without losing to much power this means i can get as far back as i want within reason.
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  • 4 months later...

Hello Guys!

 

Just to add some spice to eternal discussion on electric matches. I work with bridgeless matches which worked so far in 100% cases and they're simple to make. The procedure I followed is clearly described at http://www.frogfot.com/pyro.html#elig which is mentioned earlier in this topic. The firing device is Capacitive Discharge unit from disposable plastic camera fitted into a small plastic box. And that's it. Having seen it's easy to make those, I wouldn't bother soldering those tiny steel wires or so....not any more. This may take longer because bridgeless ones require drying but you can make hundreds of them in relatively short time and then enjoy in leisure.

 

Blaf

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