One Entry 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.
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Redcoat
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Mon Oct 01, 2007 11:49 pm

Hi all,

A little over a week ago I posted a topic asking about guns that you have to spray the fuel in through the same hole as the Potato gets shot out of.

well I decided to make it from left over parts of my Pneumatic "Sniper" Rifle and well here it is.

It's a good cannon and can shoot a spud just over 40m (131.2336ft).
It uses a BBQ lighter just shoved in the back as an Igniter.

A Con is that venting takes ages, and can be a pisser. :roll: .

I didn't think that it was worth a video because there are so many vids on Youtube about simple Combustions that it would go un-noticed.


Happy SPuddin'
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There it is.  It can also shoot Deodorant cans too. ; )
There it is. It can also shoot Deodorant cans too. ; )
Poo.
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spudgunnerwryyyyy
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Mon Oct 01, 2007 11:53 pm

Ok, the bbq lighter stuck in the back is not safe. Even if the stem is sealed in the lighter part could fail. If you want to reuse it take it apart and get the piezo-pushbutton and wire that to the back of the cannon. I recommend getting a brand new bbq pushbutton igniter. It has a bigger spark and will last way long and be WAY safer.
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Mon Oct 01, 2007 11:53 pm

Thats cool, has a real sawn off shotgun/grenade launcher feel to it.

Edit: Spudgunner,
Your right it would probably be safer for him to do that, but it wouldn't look as cool.
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spudgunnerwryyyyy
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Mon Oct 01, 2007 11:58 pm

Sorry for being so harsh on my last post. Besides that lighter its a tight ass cannon. For venting consider putting a female quick disconnect in the back, similar to removable propane setups, so you could hook up an air compressor to vent.
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Redcoat
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Tue Oct 02, 2007 12:55 am

Thanks, for the comments guys. Spudgunerwryyyyy, you don't have to be sorry for being harsh, people who post a cannon should expect just a little criticism.

The BBQ lighter isn't actually sealed in the back at all. All you do s hold it into the hole (with tight pressure). I know it's as unsafe as hell. i do where a welding glove on the hand that's holding the lighter.

It's supposed to have a Sawn-Off/Grenade Launcher/Riot Control look to it.

For venting I take out the lighter and wave the tube around and blow into it etc. It would take on average 25 seconds to vent for the next shot. Which is okay.

And the Ignition comes from the actual flame of the BBQ lighter.



Happy SPuddin'


Edit- I did try to get the Piezo lighter thing out but the spark from it actual goes along the whole thing so it's useless for a cannon like this.
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Tue Oct 02, 2007 1:18 am

Welding gloves! man your a whole hell of a lot safer then me. I'd be firing that thing with no gloves with nothing but my boxers on and a gallon of redbull in one hand an that puppy in the other.
Good choice of hand protection.
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Redcoat
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Tue Oct 02, 2007 1:31 am

That said, I first shot this cannon without gloves on and it all came spewing out the back and burnt my fingers and they went all hard-like.
So to be on the safe side welding glove is good. Better safe than sorry.
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f.c
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Tue Oct 02, 2007 5:52 pm

i used to have a cannon like that and i connected it to an air compressor to vent it and pressurize the chamber. used a bbq igniter to ignite. i ended up selling the gun for like $10.
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Redcoat
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Tue Oct 02, 2007 5:56 pm

Yeah, i was thinking of adding a small air-tank along the bottom for venting but the Gun's really good as it is and a venting chamber would be pointless.

Happy Spuddin'
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tsb
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Fri Oct 12, 2007 6:37 am

It's alright mate, but im not trying to be harsh or anything, my sisters boyfriend made one EXACTLY like that and theirs shoots a decent 120m..
So why does yours only go 40?

Cheers,
tsb

PS: I agree with making it so you can vent it

PSS: Why is it dangerous to have the BBQ igniter in the end?
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Fri Oct 12, 2007 6:41 am

PSS: Why is it dangerous to have the BBQ igniter in the end?[/quote]

Because sometimes the ignitor exits the unit just as fast as the spud :wink:
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Redcoat
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Fri Oct 12, 2007 3:55 pm

Well, as long as you hold it in there hard enough, it won't come out.

@tsb, Try because I made this in about 3 minutes. The lighter has the worst seal at the back, and combustions aren't my thing, this is leftover from my Pneumatic Rifle.

And After trying different fuels, such as Hairspray, i have managed to up the range to about 80m as well as trying to get the C:B ratio just right, 1:1 was what I thought everyone says, Plus I'm about to try propane. :twisted: .

So, as a spare parts one-off put-together it's pretty good.

Happy SPuddin'
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Fri Oct 12, 2007 6:25 pm

Looks pretty cool and simple, I like :)
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