This is a derivation of something I found in a book (Gonzo's Gizmos or something). It's pretty simple to make, and it creates a small spark which you can use for triggers on spud guns (probably), film can cannons (definitely) and tennis ball mortars (hope so, that was the idea here!)
This is something you can easily do in under an hour, and all you need is some wire, a box, a cigarette lighter and a hot glue gun!!!
Step 1: Get Whatever You'll Need...
This is simple, which is one thing that makes it such a handy little device-thing.
Here's all you should need...
A Cigarette or generic fire lighter-make sure this is the "electric" kind, as only these will work.
Some sort of small box-anything will work here....hopefully.
A few feet of electrical wire
Some utensils to cut stuff and make holes in said stuff
A small piece of something sturdy-I used a block of wood
A hot glue gun (with hot glue sticks)-this attaches stuff (durrrrrrrrrrr)
A few inches of sturdy wire-Coathangers and paperclips will work just fine
Heavy-duty wire snipper things
Here's what helped for me...
Some aligator clips-two
A hammer-(guess what this was for..heh heh heh)
A screwdriver, if a hammer isn't cerebral enough for you...pah, screwdrivers
warning-theres a high chance i forgot something really important.....so sorry if I jump to something I missed here...te he he.
IMPORTANT-DO NOT USE A SOLDERING IRON!! I know it's in the picture but RESIST THE URGE!!! I thought it would work, but IT DOESN"T!! DONT DO IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!111one
Step 2: Retrieve Thine Ignitor-thing
The core of this project is the piezoelectric ignitor from the lighter you are holding/playing with/using to set your (or others') house(s) on fire.
Anyhow, that's the reason why only the electric lighters will work....
Your mission, should you choose to accept it, is to get that little thing out of its casing!!!
Be careful here...if you're using a barbeque/fire type lighter, I'd advise being a bit careful, as these usually have little rubber hoses which can burst and spill butane on your fingers/hands. Worse, if you had the bright idea of using a power tool to saw the thing in half and save yourself time, the fuel will very probably explode and possibly kill you.
Cheery, isn't it?
anyway, I tried both sorts, and the cigarette lighters are waay easier.
For my sake, i'll pretend that the reason I tried both ISN"T because I melted the first one with a soldering gun.
Luckily for you, I've provided helpful images for both the subtle...and the not-so-subtle.
Also, that last picture is one of that tiny little thing you're after.
Step 3: Make a Convenient Box for Said Ignitor
As well as making the whole rig SLIGHTLY more aesthetically pleasing, this handy box also prevents you from shocking yourself and not whatever you're (trying) to ignite.
First, before you do anything, put the ignitor's base on your index finger and the top underneath your thumb. Squeeze.
If you didn't, you probably need a new ignitor. Go find one.
This step is pretty simple. Actually, this whole instructable is. Shhhh.
Take your box, and estimate where the middle is.
Now realise that your estimate sucks and is way off. Measure the real middle, you lazy bum.
Having done all that, cut a small "X" centred over the hole.. push the little triangular flaps aside and shove the ignitor into it, just to see that it fits.
Figure out how much you can have inside the box while leaving room to depress the button all the way.
Cut the tiny piece of wood, and glue it into place under the ignitor, so that the ignitor won't fit into the box any more.
anyway. now take your handy-dandy hole-making device (drill) and fins a suitable bit for it (about the size of the ignitor bottom).
Make sure you're holding the drill straight, and drill through the hole in the box straight into the piece of wood, about a quarter of an inch. The ignitor should now fit securely in said box.
If it doesn't, make it fit. *pounds open palm*
Now just make sure you havent covered up any metal contacts on the ignitor, in preparation for the next step.
apparently, I completely forgot to take pictures of this step. Woo-hoo! go me.
Step 4: Attacheth Thine Wires
This is a prettttyy critical part of the whole process here. Attaching the wires to the ignitor. Most ignitors of this sort have two contacts. One is on the top, and one is attached to the side. They oughtn't be hard to find, as they're usually little metal plates that rather stand out from the white plastic.......
If you got your ignitor from a cigarette lighter, a colored plastic button may be covering up the top end, in which case, you will probably find a tiny metal rod sticking out. use this.
Make sure the ends of your wires are stripped, and wrap one of the stripped ends around the tiny copper pin. If this doesn't exist on your lighter, just fray the wire a bit and press is flat against the metal plate on top of the ignitor.
Now, take the glue gun and CAREFULLY squeeze some hot glue onto the joint. Be VERY careful, as if you don't do this right, you'll insulate it and NONE of this will work. Hah..
make sure it's secured, and follow a similar process for the bottom contact. You can now replace the ignitor thing in the convenient box we just made.
Personally, I drilled holes in the top and side of my box to run the wires through. I glued them in. This helped decrease the stress on the hot-glue joints, and, i hope, extended this thing's life somewhat.
After you're sure the wires are pretty well secured, wrap a piece of tape around the ignitor where you attached the second wire...this helps prevent a spark on the ignitor itself.
Step 5: Attach Clips to Said Wires
This just adds to the utility, because it allows you to use this handy little box for whatever combustible devices your evil little mind can think up. It's pretty simple, just attach some clips to the wires. I used alligator clips, but most anything would work...paper clips probably. I admit, i used a soldering iron, but on the 'materials' page i meant that for the piezoelectric thing. SO!!!
Just solder or hotglue some clips on, making sure there's a good electrical connection.
Step 6: Rig Your Chosen Weapon
This is what you'll need to do to your weapon to get it to work with this. I designed this with my tennis ball mortar in mind, so bear with me.
You'll need to drill two holes in the combustion chamber of the thing. Try to get them about across from each other, just to play it safe with short circuiting, but it's not all that important.
Use your manly wire snip things to cut two 2-3inch lengths (for tennis ball mortar, that is...make it the chamber width)of coathangar wire (or paperclips, or whatever!!!!). Wrap about an inch of electrical tape around the middle of both for insulation. Hold one of these into one of the holes, and look down the barrel (or have someone else do it, whatever) to see if this lines up right. It ought to stick just about into the middle. Glue this in place.
Do the same for the second rod. Line this up carefully...Ideally you need about an eighth of an inch gap between the two wires. That's about as far as most lighters will make a spark. A little less will still work, because typically whatever you're using to fuel this thing will ignite pretty easily.
Step 7: Finish Up and Test!!
Now all you need to do is clip the wires onto the two ignitor contact rod things! Try looking down the barrel and pressing the button. Out of experience, don't get too close. I managed to shock my nose when this thing wasn't insulated well enough...it seems the insides of these cans are really conductive due to the coating they give them. the spark traveled the whole cannon's length and hit my nose...hah.
You ought to see a spark somwhere in the barrel. if you didn't do a very good job insulating those wires , then you might see a spark at the base of the rods. don't worry...this will still work (I think).
Good luck with your new and more convenient firing trigger box thing. Please comment if you have any complaints about the instructable/device or ideas for improvement!!