need some help.. building a top notch gun.. expert needed

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stevo
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Joined: Fri Mar 31, 2006 12:05 am

Fri Mar 31, 2006 12:25 am

well i have had some experience with spud cannons in the past 7 years.. about 5 years ago i built a very large abs cannon that i still have not fired for fear i will blow my head off.. well not really its just the fact that i live in a city and just haven't had the time to go out to fire it or finish it. the original plan when i built it was to eventually hook a propane system to it.. (keep in mind at that time spudtech had just started doing the propane system and i copied his exact design, minus the propane system). anyway.. today i got bored and decided to look and see how the spud online community has grown.. and wow.. so much has changed.. fans, constant sparks, hybrid guns.. anyway i decided i wanted to build a new gun.. or convert my other one that i was describing above into a propane powered cannon.. anyway.. i have been researching and haven't learned too much due to lack of plans on the net.. i am seeing that alot of people are using the 80mm fans to mix the propane because of something to do with oxygen?.. i am very confused about the matter. but basically i want to make a cannon or convert my cannon to use propane, be able to refire in less than a minute, and be as loud/quiet as a classic combustion gun.. now as far as loudness goes.. i'll take what i can get, quiter is better (i live in california) but if its a problem, then no worries..

i just need to find a website with some real plans that are thurough to build what i want or i need to find someone that knows what they are doing that could explain some things to me..

anyway, i thank you guys for reading this so much and i hope to hear from ya soon! :)

ps. my current 5 year old unused cannon i was talking about was based off the size of the 3 cannons pictured here: http://www.spudtech.com/images/products/launchers.jpg

thanks again :)
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Atlantis
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Fri Mar 31, 2006 9:59 am

Everything you need for fans, propane meters, and a few other things can be found here.
http://www.spudfiles.com/Main/how_to.php
"There isn't a problem in the world that can't be solved by the proper application of explosives"
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boilingleadbath
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Fri Mar 31, 2006 3:24 pm

Answears to some questions:

The fans (refered to as "chamber fans", which makes sense considering where they are) are used to mix the flamable gasses in the chamber, and to facilitate venting.
Mixing the flamable gasses increases preformance some 50% as far as energy goes, as seen in this <a href="http://www.burntlatke.com/jpg600/fan-data.gif">chart</a>.
(and <a href="http://www.burntlatke.com/fan.html">here</a> is a nice artical on chamber fans)

As to the noise, <a href="http://www.burntlatke.com/index.html">burnt latke</a> has done some excellent tests on chamber:barrel ratios. (under "launch examples")
I recomend a ratio of roughly .8:1 or .7:1 for a quiet launcher.
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