SpudFiles

Sorry guys, looking at your lovely forum and seeing the types of cannons you guys make.. gives me one hell of a hard on

But I'm an amateur and I apologise for wasting your time reading this and replying But i've nearly smashed my cannon into a million pieces as i cant figure this god-damn problem out :@

So here it is:
I made a simple combustion cannon with one of those BBQ sparkers and for some reason it wont spark in the chamber..

So what i mean is.. you have the button you push that creates a spark and then is meant to send the shock down wire to two metal plates at a short distance from each other that the spark jumps between which ignites the cannon. Yes you all know what I mean im just a newbie at this sort of thing.

MY PROBLEM is that the spark doesn't travel down the wire..... what im thinking is.. that when you put one of these in a BBQ the BQQ is grounded?? and that allows the spark to travel down the wire??

I dont understand why the goddamn f*ckn spark wont travel down the wire and into the chamber so my whole trigger system is buggered!



So after wasting all you tiem reading that.. How can i fix my probably simple stupid problem?
Im so frustrated, ive looked everywhere i cant figure it out without asking a question Please help me !

Thanks guys!

You have got two wires right? one going from the bottom of the sparker, halfway through the gun the the spark jumps to the other and back up to the side of the sparker.

2 wires??

For some reason my computer wont pick up my camera so i cant post a picture of the cannon but i drew a quick ms-paint version of what it basically looks like

attached file

where it says
'spark?'

is where i want it to spark but its not sparking.

Electronics 101: Electricity won't just flow down a wire, it has to be part of a circuit... You have to have two wires, one connected to each terminal of the piezo... Some BBQ sparkers simply have a small tab of metal near the top which functions as the second terminal. Once you have one wire coming from each terminal, a spark will jump between them if they're close enough.

What Insomniac said, and Bobsta you were on the right track with the "BBQ is grounded".

The BBQ isn't actually grounded, but the metal BBQ is one of the "wires" that completes the circuit. Since your gun is, presumably, plastic you'll need to connect a wire to the metal tab (or whatever) on the BBQ sparker and run that wire to the second screw that makes up your spark gap. For a typical BBQ sparker the spark gap should be about 1/16" to 1/8" wide.

You can find the metal tab, or whatever it is, on the sparker by just holding it in your hand, along with the one wire you have. Someplace on the body of the sparker there be spot that'll zap you if you touch it and the end of the wire while pushing the button.

On a BBQ, the sparkers are often setup the same way the spark plug in a car is. There is only one wire to the spark plug, the other leg of the electrical circuit is through the metal part of the spark plug body to the metal of the engine then via a wire from the engine block back to the negative post of the battery. (Lights and other accessories on a car are often done the same way, the metal chassis of the car is one of the "wires" for the electrical circuit.)