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Igniter HELP

  1. Jul 1, 2007 #1
    igniter HELP!!!

    hi i dont no if im doing this right but its my first post or whatever u call it ...anyways i need help making an igniter for fireworks. I saw a plane online i thought i could make farliy easily but im confuses. Ok it said that if you have nichrome wire witch if u dont no is the wire inside of a toaster that gets red hot... u can take the wire and atach a 9 volt battary to it throught to wires... so i bought a toaster took the wire out hooked it up to a 9 volt battry and it did not get hot enof to set off a fuse sooo if u know what im doing wrong or if u have any advice it would help alot.
     
    Last edited: Jul 1, 2007
  2. jcsd
  3. Jul 1, 2007 #2

    Danger

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    Welcome to PF, Bassfreeak.
    To start with, be very careful dealing with this stuff.
    As to the question, nichrome wire in a toaster is a lot thicker than that used for rockets. It's designed to work with AC mains electricity, and a 9-volt battery just can't provide enough juice to heat it up. You can buy real exploding bridge wires at most hobby shops that deal with rockets. (I think that Solar is a brand name.)
    If you can't find them, you can always cut the glass off of a camera flashbulb and wire it up.
     
  4. Jul 1, 2007 #3
    thank you is the igniters u r talking about use the blackpowder tip and if the wire in a toaster is to thick do u no where i can buy thin wire for cheap
     
  5. Jul 1, 2007 #4

    Danger

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  6. Jul 1, 2007 #5

    xez

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    You don't really need especially thin wire if a somewhat
    slowly increasing heat is sufficient to ignite your fuses.

    If you get a standard car battery or something at least
    comparably powerful, you can easily cause red-hot heat
    and rapid melting of a couple inch long piece of,
    say, 30 gauge magnet wire or wire wrap wire.

    Just take some heavy battery 'jumper cables', clip them
    to your 2"-3" long thin wire, then *momentarily* connect
    the other end of the jumper cable to the battery and
    that thin wire is going to glow white hot and melt within
    well less than a second.

    For thin wire you could also just unravel some strands of
    wire from a thin stranded appliance cord from
    some broken household appliance / gadget. Typically
    you'll find seven or more strands of bare hair-thin copper
    wire woven together to make the cable.

    An alternative would be to use something like an ignition
    coil setup from a car -- ignition capacitor, diode,
    coil, momentary physical contact to energize the main coil
    with 12V of the appropriate polarity, and a length of high
    voltage wire from the output of the coil to a couple of wires
    held 1mm apart where the spark is desired.

    Disclaimer: use appopriate heavy gloves, overalls, eye
    protection, and physical / chemical / electrical safety
    when doing anything like this. You can easily destroy
    the battery if you let the jumper cables short together,
    or if you let high current continue to flow for more than
    a several seconds before you recharge the battery.
    Even 12V DC from a battery can be lethal if you were
    to conduct it through yourself, so don't let that happen.
     
  7. Jul 1, 2007 #6
  8. Jul 1, 2007 #7

    xez

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    The advantage if it melts is that the battery often
    disconnects itself from the wire so that current stops flowing
    rapidly.

    Anyway, yes, they make commercial igniters which you can
    order online or get at a hobby store, or you could use some
    of the thin nichrome wire and a smaller battery.

    I'm sure if you had a jacob's ladder or tesla coil handy
    those could be used too.

    Use whatever works for you; there are a few choices.
     
  9. Jul 1, 2007 #8
    thanks do u no where i can buy thin nichrome wire cuz i called homedepo lows hobbylobby and they all had no clue what nichrome wire was so if u no that would be great and if i do gey how low of a battry could i use and how would i use it
     
  10. Jul 2, 2007 #9

    xez

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    That's probably the commercial solution for you.

    http://www.towerhobbies.com/rockets/listings/rocket_engine_igniter.html

    For nichrome wire .. try:
    http://www.heatersplus.com/nichrome.htm
    or use your favorite search engine to look for other
    suppliers; maybe OMEGA sells some.

    Try the 31 gague or maybe something between 30 and 40;
    anything with a lower number may be too thick and not
    easy to heat without a lot of current.

    An easier to find local source might be just buying a
    wire-wound resistor with as high of a resistance in a
    small form as possible e.g. 500 ohms, crack it carefully
    open on one end and unwind the wire.

    I know that 6V lantern batteries could be used, but they're
    rather expensive and not commonly found these
    days, that's why I suggested a car battery or a similar
    motorcycle battery or a small lead-acid battery from the
    battery backup of a UPS or alarm system or emergency
    battery backed up exit light or something.
     
  11. Jul 2, 2007 #10
    thanks agen i gess im going to have to order it online but like i was sayin people on the enternet are useing a 9volt to get like 1 inch of nichrome red hot .. if the 9v worked i have one of those modle reocket igniter boxes it the two wires that have alagator clips on the end how would i get it to work with that
     
  12. Jul 2, 2007 #11
    i cant seem to find the hobby box that u put it all in if u no were i can find 1 tell me
     
  13. Jul 2, 2007 #12

    xez

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    9V batteries don't have much energy, one would be
    dead after only a few uses, that's why it's better to use
    a rechargable battery.

    I'm sure that if you put eight charged
    2000 mAh rated AA batteries together in series it would
    be much better than a 9V battery, and they'd be
    easily recharged in a common charger.

    You'd be looking at something like 36ga or
    even thinner 40ga. nichrome for best results of
    conserving the battery to allow for maximum use.

    You could just use 16ga speaker wire to couple the
    battery pack to the nichrome, and put a somewhat
    heavy duty 120V/8A rated momentary normally open
    pushbutton switch in-line on the speaker wire to
    actuate the thing.

    At least in the good old days you could get a battery
    holder for 8 AA batteries at Radio Shack; maybe you
    still can.
     
  14. Jul 3, 2007 #13
    if i was going to combind 8 aa batterys y cant i just combined 2 9v.... and do u no were to get that littel black box
     
  15. Jul 4, 2007 #14

    xez

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    Well eight AA's have way more energy than even two
    9V batteries, that's why it's better to use 8xAA rather
    than 2x9.

    Also rechargable AAs are often cheap whereas even
    non-rechargable 9V batteries are expensive, and the
    non-rechargable ones are more so. That's why they
    use AAs in all things like cameras and never 9V batteries.

    You can use 9V batteries if you want but they'll cost you
    more and go dead faster; if I was going to spend the
    bucks I'd spend it on a small lead acid or several
    NIMH AAs and save money and time in the long run
    rathar than weak 9Vs. It's your choice.

    I don't know about pre-made igniter units, I'm sure
    that most any online store that caters to model rocketry
    would have them for sale.. but there's not much to them
    other than a few batteries in a case and a switch..

    I already showed you where you could get the igniter
    electric fuses for rocketry, and I'm sure they'd work for
    most consumer fireworks on the fuse too.
     
  16. Jul 4, 2007 #15
    thanks im going to buy 40 gage wire off of ebay and i got a black penciel box bit i acnt find where to get the 8 aa battry thing
     
  17. Jul 4, 2007 #16

    xez

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