Butane Fueled Micro

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.
PVC Arsenal 17
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Mon Jun 26, 2006 9:21 pm

Here is my new butane fueled micro cannon. It consists of 1 male adapter, 1 slip cap, 1 threaded cap and 1 coupling. All fittings are half inch. The coupling is the carriage for the cannon's onboard fuel tank which is a BIC Mini lighter. A tube runs from the lighter to a metal nozzle that fuels the chamber. The peizo ignitor is JB welded into the threaded cap and the barrel is taken from an airsoft gun and JB welded into the slip cap. I heated a metal rod and sunk it into the back of the barrel so that bb's or whatever ammo won't roll into the chamber.

I'm painting it tomorrow but I was too impatient to wait until afterward to post it up! Pics will be posted again after the paintjob. I have only done a test fire so far but it worked remarkably well. After each shot you must take off the cap with the peizo to allow oxygen to enter the chamber.

Feel free to ask any questions about how to build it.

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UPDATED PICS!! v v v SCROLL v v v

*this is not a very powerful gun so don't be dissapointed if you make one and it's weak*
Last edited by PVC Arsenal 17 on Wed Jun 28, 2006 10:34 am, edited 2 times in total.
djt
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Mon Jun 26, 2006 9:24 pm

i love it. i have tried many times to make a butane fueled mini but failed. the fuel will never ignite, even with a nozzle. ever have this problem? well done.
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Mon Jun 26, 2006 9:25 pm

Well I haven't used it extensively yet but I think the key is having plenty oxygen in the chamber.
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frogy
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Mon Jun 26, 2006 9:47 pm

I accidently bought some 1/2" pipe so I think I'll make one of these, but I'm going to buy a 1/2" saddle tee or a 1/2" repair coupling and make it have a handle with the Peizo inside...

Since my pneumatics barrel is 1" I tihnk I'm going to make PVC Rockets out of my 1/2"' pipe, but I'll have plenty left over if I do...
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carlbelcher
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Mon Jun 26, 2006 9:53 pm

The main problem with minis not firing is the air/fuel ratio. Because the chamber is so small you can only use the smallest amount of fuel before the air/fuel mix becomes to rich to ignite.

I use a small butane lighter to fuel my mini.
Zorrowannabe9
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Mon Jun 26, 2006 11:02 pm

with my mini (chamber is a 3" 1/2" PVC pipe nipple) basically had to spray a tiny amount of w/e in it then wave it around for a few seconds for more oxygen.
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Tue Jun 27, 2006 10:41 am

I painted the entire gun flat black today and I've been shooting it all morning. For a while it wouldn't fire because I was blowing into the chamber to give it fresh air. I finally figured out that I was actually breathing co2 into it and not fresh air. Now after every shot I wave it around for more oxygen.

This cannon's power is the equivelent of a toddler thwroing an airsoft bb which obviously is not powerful at all. It doesn't even compare to my other pill bottle micro that uses AXE for fuel. It seems that it is extremely hard to get the proper fuel to air ratio with a cannon this small. The combustion chamber is also a bit too small to get good power.

That doesn't upset me though because it was really just a project to see if it could be done and now I'll scale it up a little bit and make chamber larger and also change my fuel tank to the refillable cartridges inside those small soldering torches. I suggest to anyone building this design to add a coupling between the male adapter and the cap for extra volume.
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drac
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Tue Jun 27, 2006 12:13 pm

Why make the chamber longer? I find that a shorter, wider chamber lets you get a better fuel mix than a skinny long one.

My Patriot Ressurection cannon has a 4x10 chamber, it it is much easier to ignite and get the right fuel mix than my Mini Patriot, which has a 2x20 chamber.

Don't get me wrong though, I like this gun. it's small and simple.
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Tue Jun 27, 2006 4:16 pm

I guess you're right maybe the next one will have the same cap and male adapter design just using 1" fittings to keep it short and fat.

As weak as it is it's still fun to shoot!
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huse_spud
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Tue Jun 27, 2006 7:56 pm

frogy wrote:Since my pneumatics barrel is 1" I tihnk I'm going to make PVC Rockets out of my 1/2"' pipe, but I'll have plenty left over if I do...
did you ever find ammo for that 1" barrel (besides taters)?

i thought little bouncy balls would work

i'm almost finished with my newest gun, stud-zooka, that launches softballs (just need a few small parts).

it's a pnuematic, with a modded solenoid i made last night.

pvc aresenal, that's the COOLEST mini i think ive ever seen on this forum!
and use spit wads for mini's that's what i did with mine (good seal).
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Wed Jun 28, 2006 10:18 am

Here are more pictures:

Image

Image
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frogy
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Wed Jun 28, 2006 10:29 am

100 times better painted, You get the sweet micro award!

I'm going to make one that's 1.5" to 3/4" CPVC
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drac
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Wed Jun 28, 2006 2:36 pm

frogy wrote:100 times better painted, You get the sweet micro award!

I'm going to make one that's 1.5" to 3/4" CPVC

:shock: Took my idea! SON OF A #&$*&!!!!!

lol, jk. I did have that idea in mind though, but I'm kinda in doubt about whether I should use a shorter fatter chamber for aforementioned reasons.
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beebs111
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Thu Jun 29, 2006 11:20 am

you took my already built idea :shock: :lol: except mine is a hybrid :lol:
in the upcoming presidential election, there will be several candidates who will be running, one of whom is Hillary Clinton. Now WAIT A SECOND!!! I though there was some sort of rule that prevented someone from serving more than two terms in office. Vote Against Hillary: Presidential Elections 08
PVC Arsenal 17
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Thu Jun 29, 2006 3:07 pm

could you explain what a hybrid is because i really don't know.

how does yours work?
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