My first Cannon

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.
JT07
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Tue Mar 10, 2009 6:44 pm

Being my first cannon I wanted this to me moderate in size.

Its 90% complete. I just have to add the fan battery and control box.

Specs:

Chamber is 3" x 10" PVC
Barrel 1 1/4" x 30" PVC
All other joints are ABS
Barrel is detachable
Electronic BBQ igniter with dual sparks
Safety switch with red switch protector
Chamber fan will be powered by 8 AA batteries
Propane tank held in with hard drive magnets
In the future I hope to add one of those big PVC ball valves to the clean out cap.

At first I thought I overdosed on the amount of hose clamps I used. But i kinda like the look.

I've also built a suppressor out of extra barrel and chamber pipe. Drilled holes in the inner pipe, wrapped in steel wool, and encased in larger outer pipe. Pics to come...

Thanks starman and jimmy101 for bits of info in a previous thread.

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Here you can see the first spark and the light from the second spark in the rear. To the left, you can see a slight blue glow from where the red wires touch each other. Its only noticeable in the dark. I wonder if anyone else has this problem?
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covey12
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Tue Mar 10, 2009 6:47 pm

nice, that cannon looks way better than normal first cannons, looks good im guessing you havent shot it yet since its not done but when you do could you post some dmg pics, looks like it could do some oh yeah, ill give 25 dollars to anyone who puts there finger between those screws :D
TurboSuper
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Tue Mar 10, 2009 7:26 pm

Nice cannon, especially for a first!
covey12 wrote:some oh yeah, ill give 25 dollars to anyone who puts there finger between those screws :D
While I haven't put my finger in that specific setup, I've zapped myself with a BBQ sparker before...can I still have $25? :D
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
talknspud
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Tue Mar 10, 2009 7:53 pm

Where your wires are touching it sparks...I have that problem too. Normal insulated wires are only good for a few hundred volts. The one you use (given that you have just 1 double A) is about 12,000. In mine I use 2 batteries and have 3 spark gaps and it works wonders. To get rid of the extra spark I spread them apart and used some silicone inside some large insulation. It still looks good without the loss of current through the insulation.
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jonnyboy
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Tue Mar 10, 2009 8:05 pm

ill give 25 dollars to anyone who puts there finger between those screws
They don't hurt that bad. :?

Nice first cannon a lot nicer than most first's. Although you got some wires running every where and I would have gone for a smaller tank.
mobile chernobyl wrote:I can shoot a Canuter Valve off my '82 Chevy Ram F150 AT LEAST 3/4 Mile with 'ma cannon made of soup cans duct taped together, then I just squirt some bacardi 151 in the chamber and hold up my cigarrete lighta and WHOOSH! That thing flies at least 3/4 mile
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sputnick
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Tue Mar 10, 2009 8:07 pm

Excuse me while I wipe the drool off my keyboard...

That is a really nice gun, looks absolutely fantastic, although I would put a longer barrel on that sucker :wink:

I look forward to seeing more of you here :)
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cannon monkey
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Tue Mar 10, 2009 8:13 pm

thats like 60 times better than my first cannon
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starman
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Tue Mar 10, 2009 9:26 pm

You're quite welcome. You have done a nice job on this cannon, especially considering it's your first one. I'm having a hard time coming up with real critique short of the standard barrel is too short stuff.

Your spark gaps look a little wide and you might find yourself having ignition troubles at inopportune times...wouldn't hurt to close them down to 1/8" each if you can. I like the idea of one of the gaps being behind the fan.

The hose wrapping around the butt of the gun could get in the way of standing it up or make it easier to catch on something and pull loose. Also, beware if you do stand it up on end, the propane hose will likely flood....keep and eye out for that anyway. You should try to keep the bottle pointing up or at least level.

I assume you would hold it by the barrel with your left hand and fire it with your right...good for a lefty... For right hander, I would have put the firing box on the left side, held it with my right, fired with my left.

These are mostly piddling things though. Good workmanship!
Last edited by starman on Tue Mar 10, 2009 9:30 pm, edited 1 time in total.
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mark.f
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Tue Mar 10, 2009 9:26 pm

That is very well put together, for any cannon, not just a first cannon.

Congratulations. The only thing I could possibly suggest would be to get a better fitting propane holder.
le_rufus
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Tue Mar 10, 2009 11:26 pm

Great first cannon dude, and an advanced combustion as well.
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jackssmirkingrevenge
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Tue Mar 10, 2009 11:36 pm

Not only is it in excellent first project, but congratulations for showing us nothing but the cannon in the photos, I wish all new (and some old!) members shared your photographic insight ;)
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mark.f
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Tue Mar 10, 2009 11:55 pm

Wait until you see what I've acquired for my next cannon pictures, Jack. :wink:
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jackssmirkingrevenge
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Wed Mar 11, 2009 12:10 am

markfh11q wrote:Wait until you see what I've acquired for my next cannon pictures, Jack. :wink:
Good lord, is it an artificial foot? lol
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D_Hall
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Wed Mar 11, 2009 12:36 am

General comment: The arcing from wires touching each other should be solvable by using automotive spark plug wires. Get the type intended for hot rodders (lower resistance).
Simulation geek (GGDT / HGDT) and designer of Vera.
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Carlman
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Wed Mar 11, 2009 1:54 am

Very nice work mate! Great for a first cannon, infact great for any spudgunner new or vet!
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Aussie spudders unite!!
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