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| king edward |
 Posted: 05/20/2008 13:45 PM Post subject: old cannon re invented! |
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Private
Joined: 11 Nov 2007
Posts: 7
28.58 Spud Bux
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Hi, my old combustion cannon blew up in my mums face and got left around my future father in laws house and I thought it had been thrown away!
recently I've been wanting to make another one and when I mentioned it to my father in law he said he kept my broken one in his shed, so I went and had a look to see if I could salvage any bits i.e the sparker (mainly)
tbh most of it can be re used so I'm gonna re invent my beast asap, all I need is a 4" -2" converter section and coupling, a bit of pvc cement and a prayer and I should be launching those potato mortars into orbit again!
Its only a simple design but I'll post a pic on here when its ready, I gotta work every day so it may take a week or two 
I might try out putting a computer fan in the chamber and see how it improves. My cannon is made up of a four" dia' pvc pipe about 2' long with a handle from an old drill which I fixed a bbq sparker into the end of so I can hold and fire in one hand and steady aim it with the other. The barrel is 2" dia' white pvc and about 4' long but I might cut it down to 3', do you think I should?
I know you lot will probably take the p out of my cannon because yours are more evolved but I'll post a pic anyway   |
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| psycix |
| Posted: 05/20/2008 14:51 PM Post subject: |
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Major General
Joined: 25 Jun 2007
Posts: 1591
86.93 Spud Bux
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How could that cannon blow up? Did you solvend-weld it properly?
Did you use pressure rated pipe and fittings?
You should defenately keep the long barrel. You will get more power outta that.
Well post your old cannon and good luck on the rebuild  |
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| prospudder |
| Posted: 05/20/2008 15:16 PM Post subject: |
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Joined: 19 May 2008
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no offense but if i had a cannon that blew up in my face it would be pretty sceptical about using that same pipe on another cannon it won't cost that much to just get some more pvc pipe but you can do what you want  |
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| king edward |
| Posted: 05/21/2008 1:15 AM Post subject: |
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Joined: 11 Nov 2007
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| prospudder wrote: | | no offense but if i had a cannon that blew up in my face it would be pretty sceptical about using that same pipe on another cannon it won't cost that much to just get some more pvc pipe but you can do what you want | I'm thinking it blew up maybe because it got brittle? the father in law left it pretty much outside during the winter and it hadbeen very cold out there last year. Its the only thing I can think of tbh cos the cannon was absolutely fine for months and with regular use too! |
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| king edward |
| Posted: 05/21/2008 1:19 AM Post subject: |
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Joined: 11 Nov 2007
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I just remembered having a youtube clip of me in the woods with it last summer, unfortunately the clip was made with my old phone so the pic and sound are a bit sh*tty but here you go.
http://www.youtube.com/watch?v=vdMapznnZj4 |
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| psycix |
| Posted: 05/21/2008 5:49 AM Post subject: |
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Joined: 25 Jun 2007
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| king edward wrote: | | I'm thinking it blew up maybe because it got brittle? the father in law left it pretty much outside during the winter and it hadbeen very cold out there last year. Its the only thing I can think of tbh cos the cannon was absolutely fine for months and with regular use too! |
When its stored in subzero temperatures, but used at higher tempratures, your safe.
Pvc that is room-temperature, but HAS been frozen isnt brittle anymore.
Only frozen pvc is. |
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| king edward |
| Posted: 05/22/2008 2:19 AM Post subject: |
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Joined: 11 Nov 2007
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| psycix wrote: | | king edward wrote: | | I'm thinking it blew up maybe because it got brittle? the father in law left it pretty much outside during the winter and it hadbeen very cold out there last year. Its the only thing I can think of tbh cos the cannon was absolutely fine for months and with regular use too! |
When its stored in subzero temperatures, but used at higher tempratures, your safe.
Pvc that is room-temperature, but HAS been frozen isnt brittle anymore.
Only frozen pvc is. | I suppose I didnt warm it up to room temp actually, but I fired a spud and it worked fine, it was only the second shot, fired by my mother that went wrong. The cannon I shouls think was probably at around 8 - 12 degrees celsius |
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| psycix |
| Posted: 05/22/2008 4:52 AM Post subject: |
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Joined: 25 Jun 2007
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That temperature should not be a problem yet.
There was something else that caused it to blow.
Could I see a picture of it?
I think it blew, because a tater was somewhat stuck, and thus allowed pressure to build. Was it the screw cap that blew? Or did the fitttings "unfit"? |
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| king edward |
| Posted: 05/22/2008 4:59 AM Post subject: |
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Joined: 11 Nov 2007
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| No pic as yet mate, but it was probably like you say, a tato stuck. I say this in agreement because it blew up right at the join of the 4" - 2" seperating the combustion chamber from the barrel, everything else was fine! |
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