Self Venting, Metered, New 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.
cannon freak
Specialist 2
Specialist 2
Posts: 272
Joined: Fri May 12, 2006 8:37 pm
Location: New Brunswick, Canada

Wed Apr 16, 2008 3:16 pm

Hey all!

Its been quite some time since Ive posted, made a cannon, or even been on the site, however, things have been a little boring so I decided to make another cannon.

Now its definitely not the best looking cannon at the moment, as its held together by carpet and electrical tape. I have some metal strapping but had a hard time getting it tight so I decided to get everything taped up to see what it looked like.

Specs -

- Chamber volume somewhere around 380 cubic inches.

- Barrel length approximately 5'. On the end of that particular barrel is a 3" coupling and 3" female adapter, this is because I had an older cannon which was for a much larger dual chambered cannon which had a 3" barrel and the barrel which you see which was for 2" ammo. I didn't feel like buying more pipe so I slapped on a male fitting to the end and simply turned the pipe around to use for this gun.

- Ignition is a simple BBQ piezoelectric ignitor taped o the side. This is only temporary and when I get around it it I will replace it with a nice camera flash ignition system.

- Soon I will be making a nice spark strip but for the moment all I have is a piece of kindling with two screws in it and glued to the chamber wall.

- Venting is accomplished via a one inch diameter plastic check valve, I was a bit weary about the valve but it holds up just fine under combustion. This valve is connected to an old inflatable bed inflator running off of four D - Cell batteries. This provides enough air volume to force open the one way valve and vent the chamber.

- I have made the cannon a breach loader by taking four two inch couplings and sanding the inside with a dremel until it glided over a two inch piece of pipe. I then proceeded to simply glue them together, IM a bit concerned that the glue joints holding them together may fail so I'm going to strengthen them up soon and add an extension and handle grip to the breech so its much easier to open and close.

- I rigged up a quick propane meter from pieces around the garage, it was pretty dark out when I did the soldering so the joints could definitely be a lot better but its air tight and works great. The meter only needs to be charged to 45 PSI for the right mixture in the tank, I made it quite large because I wanted to be able to use it for my other, larger cannon. At the moment all I have is a piece of garden hose hooked to the ball valve going into my gun, I don't have much of a seal there so that needs to be replaced an fixed. Soon I will be adding another piece of 3" ABS pipe to conceal that unsightly propane meter and make the gun look cleaner.

All in all its a pretty decent gun, once I fix a few things and give it a nice paint job it should look pretty sharp. Its quite a heavy little bugger though.

Well enough reading, here are a few pics, hope you like em!!

Image[/img]



Image



Image



Image


Videos will be posted when I find time to make them, hope you enjoyed.
User avatar
STHORNE
Sergeant 3
Sergeant 3
Posts: 1208
Joined: Wed Feb 14, 2007 7:50 pm
Location: Kewaunee, Wisconsin

Donating Members

Wed Apr 16, 2008 4:52 pm

wow, that thing is a monster. nicely done.

interesting propane meter set up though...but if it works, than cudos to you.

over all cost (roughly) ?
Forum Rules - follow them or else!
“Happiness is the meaning and the purpose of life, the whole aim and end of human existence”
User avatar
bigbob12345
Staff Sergeant
Staff Sergeant
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington

Wed Apr 16, 2008 5:20 pm

Me likey
CB is insane but that extra loudness just adds to the fun
cannon freak
Specialist 2
Specialist 2
Posts: 272
Joined: Fri May 12, 2006 8:37 pm
Location: New Brunswick, Canada

Wed Apr 16, 2008 5:30 pm

STHORNE - Honestly I have no idea what the over all price was, I found the ball valves out in the garage, the fittings at many different stores, and other tings lying around the house. If I was to give an estimate I'd say maybe around $70 CND, probably a bit more.

BigBob - lol, yea the CB ration is intentionally off, well off by quite a bit for quite a powerful BOOM! Got to love the power eh.

I just can't wait to work on it and get rid of the sloppiness.
User avatar
STHORNE
Sergeant 3
Sergeant 3
Posts: 1208
Joined: Wed Feb 14, 2007 7:50 pm
Location: Kewaunee, Wisconsin

Donating Members

Wed Apr 16, 2008 5:32 pm

so judging by the "CND" and the "eh", I take it your Canadian....

where abouts in Canada do you live?
Forum Rules - follow them or else!
“Happiness is the meaning and the purpose of life, the whole aim and end of human existence”
User avatar
bigbob12345
Staff Sergeant
Staff Sergeant
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington

Wed Apr 16, 2008 5:39 pm

He lives in New brunswick according to his profile

And cannon freak yeah, you always go to love that satisfying BOOM
Last edited by bigbob12345 on Wed Apr 16, 2008 5:46 pm, edited 1 time in total.
cannon freak
Specialist 2
Specialist 2
Posts: 272
Joined: Fri May 12, 2006 8:37 pm
Location: New Brunswick, Canada

Wed Apr 16, 2008 5:41 pm

lol, yep good old Canada.

I live over in the Maritimes, New Brunswick to be specific. Honestly I can't wait to get out of High School, through university and get the hell out of this province.
User avatar
STHORNE
Sergeant 3
Sergeant 3
Posts: 1208
Joined: Wed Feb 14, 2007 7:50 pm
Location: Kewaunee, Wisconsin

Donating Members

Wed Apr 16, 2008 5:41 pm

bigbob12345 wrote:satisfeing
= satisfying

fyi....spell check
lol....just rippin on ya
Forum Rules - follow them or else!
“Happiness is the meaning and the purpose of life, the whole aim and end of human existence”
User avatar
bigbob12345
Staff Sergeant
Staff Sergeant
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington

Wed Apr 16, 2008 5:46 pm

STHORNE wrote:
bigbob12345 wrote:satisfeing
= satisfying

fyi....spell check
lol....just rippin on ya
Oh bahhhh
fixed BTW
User avatar
STHORNE
Sergeant 3
Sergeant 3
Posts: 1208
Joined: Wed Feb 14, 2007 7:50 pm
Location: Kewaunee, Wisconsin

Donating Members

Wed Apr 16, 2008 5:48 pm

bigbob12345 wrote:
STHORNE wrote:
bigbob12345 wrote:satisfeing
= satisfying

fyi....spell check
lol....just rippin on ya
Oh bahhhh
fixed BTW
lol, thank you... as you can tell it was bothering me lol.

jk, i'm just bored out of my freakin mind....
Forum Rules - follow them or else!
“Happiness is the meaning and the purpose of life, the whole aim and end of human existence”
User avatar
Blitz
Corporal 2
Corporal 2
United States of America
Posts: 627
Joined: Sat Apr 07, 2007 1:48 am
Location: Illinois
Been thanked: 3 times

Wed Apr 16, 2008 7:16 pm

I really like how you made your metering dveice using copper piping. Nice job man!
Post Reply