my cannon

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
maggotman
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Tue Dec 16, 2008 7:37 am

the steel is pressure rated as are the fittings
to cut the hole in the tank i used the gass
removed the valve then filled it with water pluged the hole and took and angle grinder to it
and welded on the 2inch pipe
it uses a piston valve old bike piston with a bit of tape round it for a better fit
to test it i fild it with water and pumped up to 250

please comment

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ALIHISGREAT
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Tue Dec 16, 2008 7:55 am

i've said it before, and i'll say it again...

that thing is UGLY! :D

but it must have a fair bit of power, any chance of a vid of it firing?
maggotman
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Tue Dec 16, 2008 8:06 am

ive got to wait till my mum is out cause she goes nuts after a put a potato thro our back gate
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SP00K
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Tue Dec 16, 2008 10:12 am

Omg, that thing just made my day. That is one of THE most ghetto guns I have by far, ev3r seen.
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jackssmirkingrevenge
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Tue Dec 16, 2008 10:47 am

How awfully beautiful :) I'm guessing the chamber:barrel ratio must be pretty high and performance should be correspondingly impressive, damage pics/vids appreciated :)
hectmarr wrote:You have to make many weapons, because this field is long and short life
PhotoKirk
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Tue Dec 16, 2008 11:20 am

That's a beast. I love it.
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starman
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Tue Dec 16, 2008 11:51 am

Looks long. Can I assume you breech load somehow?

You were able to power up your chamber to 250 psi with a hand pump and it full of water...that's cool. You won't practically be able to hand pump that chamber without water to that level though. What do you consider the working psi for this cannon and what do you have to pump it to that level?

It isn't very practical because of its size but I'm sure it can do some impressive backyard shootin'. Because of that, watch what's behind your targets....like your mom's gate.. :roll: Always look beyond your actual target and assume whatever is there is expendable.
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mark.f
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Tue Dec 16, 2008 12:32 pm

He just filled the cannon with water and pumped air in. It's the same way you test water rockets. If the vessel decides to go, there's only a few cubic inches of air or so at the top of the vessel, so it's nearly the same as hydrostatic testing.
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POLAND_SPUD
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Tue Dec 16, 2008 1:04 pm

uhmm nice artillery.... I hope you have a compressor because I can't imagine filling it with a stirrup pump
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starman
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Tue Dec 16, 2008 1:14 pm

markfh11q wrote:He just filled the cannon with water and pumped air in. It's the same way you test water rockets. If the vessel decides to go, there's only a few cubic inches of air or so at the top of the vessel, so it's nearly the same as hydrostatic testing.
I understand what he did for his tests, and that's fine. I was talking about pumping it when it's in real use. Surely he isn't expecting to keep the water in the pressure vessel, otherwise large waste of chamber space.
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mark.f
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Tue Dec 16, 2008 1:27 pm

I used to fill my 11 gallon carry tank with a bike pump, or this.

It's possible, although extremely annoying. I assume that maggotman has a compressor he can use.

EDIT: Holy sh-- I hope nobody read that. Stupid brain...
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jackssmirkingrevenge
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Tue Dec 16, 2008 1:33 pm

starman wrote:You were able to power up your chamber to 250 psi with a hand pump and it full of water...that's cool.
He doesn't mention using a hand pump anywhere in his post though...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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starman
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Tue Dec 16, 2008 2:29 pm

jackssmirkingrevenge wrote:
starman wrote:You were able to power up your chamber to 250 psi with a hand pump and it full of water...that's cool.
He doesn't mention using a hand pump anywhere in his post though...
Humm that's true...I saw "bike piston" and 250 psi and assumed it I guess...bad connection on my part. Unless he has an industrial sized air compressor or a fridge compressor, the only thing it could be is some hand (or foot) pumped instrument. Yeah yeah I know, there's scuba tank and CO2....
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ALIHISGREAT
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Tue Dec 16, 2008 2:32 pm

i guess 250psi won't be his operating pressure as thats what he tested it too, i reckon he'll get decent performance at 100psi easily.
maggotman
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Tue Dec 16, 2008 2:57 pm

i got some shots in today low presser about 40psi i will try and get some pics now.
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