Stun Gun Ignition

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
ralphd
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Fri Jan 25, 2008 10:17 pm

I just received my new stungun from someone on Ebay and after scaring the crap out of the cats I opened it up. This seems to be cheaper and easier to modify than BBQ igniters both piezo and electronic as well as camera flashes but does anyone know how many spark gaps per kv? Any tips or tricks from those of you who use this method of ignition?
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DYI
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Fri Jan 25, 2008 10:51 pm

How many spark gaps per kV? That depends on how big the gaps are. Take the built in spark gap of the stungun, and don't let the total of all your gaps get bigger than that.
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jrrdw
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Sat Jan 26, 2008 5:56 am

Basically, the smaller the gap, the hotter the spark. Experiment with it, make your electrodes adjustable and go play around.
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jimmy101
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Sat Jan 26, 2008 11:01 am

jrrdw wrote:Basically, the smaller the gap, the hotter the spark. Experiment with it, make your electrodes adjustable and go play around.
But how hot the spark is is really pretty irrelevant. Any electrical spark generated this way is more than hot enough to ignite the fuel.

And, DYI is right, it isn't the total number of gaps the stungun can do. It is the total length of the gaps that matters. The sum of all your spark gap lengths must be less than the default gap width on the stungun. IIRC, the default gap is about 1", so all you spark gaps added together must be less than 1".

You should be able to do at least ten gaps of 1/16" each.

Below is an image from Latke's site. He used a 65KV stungun and there are 29 sparks in the photo.
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jrrdw
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Sat Jan 26, 2008 4:27 pm

Fuel changes the equation, so will compression if there is any. I understand what your saying. There will be a point in the gap/s to where it will work best so play be marry/have fun/shoot the liven shit out of it!
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Sun Jan 27, 2008 9:09 am

Aren't the gaps on those circuit boards 0.1" spacing, (IC spacing)? At 29 sparks, doesn't that put the gap at around 2.9"?

EDIT: nevermind, those copper soldering rings extend past the pinholes. So that would put it around 1.45".
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