Mini

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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PCGUY
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Sat Feb 12, 2005 10:21 pm

<div align="center">MINI

Provided By fiebigspudguns - <a href="http://www.geocities.com/fiebigspudguns ... udguns/</a>

<img src="http://www.spudfiles.com/official_pics/MINI4.jpg">

This is my first and only mini spudgun. My friend wanted a gun to shoot blowgun paintballs (in case you dont know blowgun paintballs are .50 calibre) so I suggested a Mini. This was the first time I had ever encountered a mini and DAMN was it a PAIN IN THE ARSE! the fuel mixtures are horribly diffictult to get!

Anyway, the chamber is 2" x 9" with a male adapter and a threaded cap instead of a cleanout. Cleanouts below 3" are very inconvinent so I used this instead. It allows for more room to put in fuel and since the threads are on the outside, they dont get all gummed up with residew. The barrel is .5" x 2' which, with wadding, fits blowgun paintballs nicely. It has a stardard BBQ sparker and one spark gap.

Luckly, I got to give this one away to my friend so I dont have to deal with its crap anymore!!!

<img src="http://www.spudfiles.com/official_pics/MINI3.jpg">

If you want to build a mini, beware! They are a P.I.T.A.!!! You will have to mess with fuel ratios until you get one which will work. Though they are pretty cool....

I plan to build a new mini (for me) with the same basic design, however using a flint sparker instead.

Provided By fiebigspudguns - <a href="http://www.geocities.com/fiebigspudguns ... /</a></div>
Last edited by PCGUY on Sat Jul 29, 2006 12:13 am, edited 1 time in total.
Yes, I am the guy that owns & operates SpudFiles (along with our extremely helpful moderators).
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theexp
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Mon Feb 14, 2005 8:49 pm

Real nice and clean, I like the handle, GANGSTA
lol :lol: 8)
calvintennant
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Mon Oct 24, 2005 6:54 pm

looks awesome, maybe a co2 one with a short coaxial type barrel, so it absolutly TINY! like a foot long that would be BITCHIN'! yeah.. and hook up a trigger system.. leavers are shitty. dont know how you would go about it though.. any ideas? also, i think the regular (.67 i think) cal. pntballs would be cool on this, more surface area = more speed and less psi! also they are more avalible (as far as i know), use a regular ontball cartrige.. i think i will do this.. great!

okay guys/gals .. brainstorm.. how to hook up a trigger system

*edit*
a hopper to..
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boilingleadbath
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Mon Oct 24, 2005 7:59 pm

"...levers are shitty."
I don't see any levers...

"...CO<sub>2</sub>..."
It's a combustion.

"more surface area = more speed"
Ah, no. You see, the sectional density is higher... it's heavier per serface area.
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drac
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Mon Oct 24, 2005 8:32 pm

I was gonna say, where the hell are the levers.

BLB, where in the name of god do you find all this info? Are you like a junior in college taking physics 202 or some crazy subject like that? :P :lol:
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boilingleadbath
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Mon Oct 24, 2005 9:12 pm

...acctualy I think I'd be classed as a high school sophmore. I'm shure I mis-spelled that, even though I had to look it up just 30 seconds ago to make shure that's what they called 10th graders.

Last summer, I did take a collage class... but that was macro economics. I think I ended up with a 108% or so, compared to the class average of about 80% (the curve:10% for showing up, and the class average on each of the 3 tests [woot! no homework!] was brought up to a 70% [from approximatly 60%])
Wow, econ majors are DUMB... I mean the <i>class average</i> was an F! (oh, and there was no studying involved here - all I did was read [majority of] the textbook)

I did take a solar system astronomy course 3 years back, did pretty well in that too.

You can probably blame the majority of it on my habit of being interested in random tidbits on how the world works, and my fortune of having a physics/astronomy professor/softcore macheinest (he worked at the now defunct [I think so, anyway] snaptite for a few years) dad.
taterjim
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Wed Nov 09, 2005 9:40 pm

I built 3 mini's in the last week or two and they range from about the size of the one shown to 5 and 6 inch chambers.
getting the right amount of fuel seemed really difficult at first ,then I found out that wasn't r eally the prob. The problem was that the thick 1/2 " chamber to barrel fitting is thick walled and seems to make it hard to get detonation . I really don't know why . As soon as I replaced it with a short metal piece also 1/2" but with thinner walls than the plastic . I started getting detonation nearly every time. With this i n mind I built the other two with 3/4" outlet and they fire nearly every time. So this might help someone who is building a small cannon. Use the largest barrell and outlet you can and if needed ,reduce it a short distance from the combustion tank.
taterjim
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Thu Nov 10, 2005 10:30 pm

Sometimes it's good to have alernative ammo and that's one good use for the mini cannons ,otherwise I would just shoot big chunks of spud or tennis balls most of the time ,but sometimes potatoes get kind of high priced ,one week maybe 1.99 and the next 3.50 for a small bag. that's when I use marbles ,acorns ,tennis balls. I put in a tennis ball yesterday that fit kind of tight ,one of those dollar store dog toys made like a tennis ball and the first shot nearly ripped it apart,It was still shootable maybe a few more times.
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longshot1068
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Sun Nov 27, 2005 10:15 am

That is why people build fuel meters. Do the math once and then you have the mixture correct everytime after that.
That small combustion is cool as hell, I dont think I could bring myself to give it away.

You dont really need to be a college student to figure out that if it is bigger it is going to weigh more and therefore will be slower if using the same charge. That is common sense. Although ( I am probably wrong ), I think that if you use the same charge and the same projectile with a lightweight wad in a bigger diameter barrel you would get the ammo to a bit of a higher velocity before it leaves the muzzle- due to the propellant acting on a higher amount of surface area. The energy doesnt get bottlenecked and squeezed thru a small opening, therefore you dont lose any energy.
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