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Spark not jumping gap

Posted: Tue Nov 25, 2008 3:16 am
by Moonbogg
I have my cumbustion gun under construction and I am working on the spark gap with a stun gun. I had the screws through the combustion chamber and the spark was not jumping the gap, instead it was flowing through the chamber walls! It seems the inside of the chamber is electrically conductive, diverting the electricity away from the ends of the screws. I tried to isolate the the electricity from the chamber walls by feeding wires into a carbon fiber tube that has a gap cut out in the center where the wires should spark, but the carbon fiber tube is electrically condictive as well! The electricity just flows from one wire, throughn the tube and to the other wire. This issue was not foreseen :cry: :cry:

Posted: Tue Nov 25, 2008 3:51 am
by starman
Are you using a PVC chamber...it is NOT at all electrically conductive. Also, narrow your gap way down to say 1/8" and keep your stun gun HV wires separated all the way from the gun terminals to each screw feeding your gap.

Show us a pic of your setup...this will help us troubleshoot with you.

Posted: Tue Nov 25, 2008 5:10 am
by Moonbogg
It is ABS pipe. I just fixed it. I isolated the spark wires with plastic tubing and it works perfect now. I am suffering from noobism a little. First time building an "advanced" or a real spud gun. So I did some things a little backwards and experienced dfficulty as a result. For instance, I completely built the chamber and glued everything up BEFORE installing the spark gap screws. So, once I installed them they didn't work of course...but anyways, looks like I got it fixed. Once this gun is finished I will submit pics for you guys to see it. My next build will be cleaner and better, maybe with clear PVC for a chamber =)
Thanks for your repies,
-Ryan