how to??

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.
jdty
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Fri Feb 25, 2011 1:01 am

im moving up in the world, up from hairspray to mapp gas. however i dont understand how to build the fuel metering system properly. if you have the gas conected to a tap with a gauge you will only be able to see how much pressure is in the chamber, not how much fuel is in there? so therefore you have to have the exact correct side of chamber and do some math to figure out what psi you need to have in there for the correct amount of gas? im sure im missing something and any help would be appreciated. pritty much just need you to explain in some detail how a fuel metering system works. cheers
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ilovefire
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Fri Feb 25, 2011 1:38 am

you have your meter pipe with the gauge on it then figer out what volume of gas you need then you can work out how much pressure you need in the meter pipe to equal that volume of gas needed, thats my understanding of it anyways
why make it if it dosent shoot?
jdty
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Fri Feb 25, 2011 1:41 am

oh right, so how do i work out how much psi i need in my chamber if i only know the volume of my combustion chamber and gas chamber? i am using mapp gas. cheers
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mark.f
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Gaderelguitarist
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Fri Feb 25, 2011 10:28 am

Got to Burntlatke.com

It explains how to go about making a meter for your gun.
so many muchness
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jimmy101
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Fri Feb 25, 2011 6:56 pm

The responses are all good, many links to very well done methods of metering. But for a start, just consider using a syringe, cheap, easy and accurate.

http://www.spudfiles.com/spud_wiki/inde ... Fuel_meter
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jackssmirkingrevenge
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Sat Feb 26, 2011 12:20 am

jimmy101 wrote:The responses are all good, many links to very well done methods of metering. But for a start, just consider using a syringe, cheap, easy and accurate.
Saw your wiki edits yesterday, nicely done :)
hectmarr wrote:You have to make many weapons, because this field is long and short life
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