my first combustion

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.
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guitarfreak
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Location: hawera,new zealand
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Sat Sep 24, 2005 11:37 pm

my dad and i made this gun,it took about 4-5 hours,spread over a week.the silver thing is the ramrod,it is made of a bit of aluminiumn u-channel that fits the barrel snugly.
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i had some trouble with the peizo,i was using one out of a long reach bbq lighter,so i forked out $5 for a second-hand ignitor out of a gas heater. it is hooked up to a spark plug with the outside curved electrode cut off,and a blob of solder on the inner electrode. it seems to work first or second click.
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the body is made completely out of metal; the barrel is stainless and about 13" long. the combustion chamber is a bit of water pipe about 11" long,with an inner thread in the end where a threaded bung is screwed in.
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i covered the whole gun in black insulation tape;it looks cool and stops me getting so many shocks. the domed thing is a deodorant bottle lid taped over the spark plug,again to stop the electricity.it makes a sort of hollow,WHOOMPH sound,not like the CRACK i expected. i have only tried it in my backyard,and i live in town,so im not sure on how far the spud would go,although im guessing about 100 meteres. i use lynx deodorant as a fuel.it seems to work good. i might upgrade to a camera flash ignition sometime,ill see what the peizo's like first.
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dongfang
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Location: Switzerland

Sun Aug 27, 2006 11:40 am

Nice enough gun; I like the steel body but not the duct tape. If you use a spark plug cable or a high voltage cable from an old CRT TV, that will insulate well, too.

Try adding LESS fuel. And butane would probably be perfectly safe with a steel gun, + more powerful, cleaner and cheaper than deodorant.

Søren
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