SpudFiles

my 9 foot tall super cannon i built for my nieghboor, it shoot 1.5 inch potatos hundreds of meters!!!

Looks very large and powerful, however, it appears in uses a ball valve. BV's have high flow, but very slow opening times. You would be much better off upgrading to a modified sprinkler valve.

However, it appears that it is otherwise well constructed. It would be nice to see a video!

it shoot 1.5 inch potatos hundreds of meters!!!

Hundreds of meters with a ball valve? What Kind of pressure are you using? Because I highly doubt you can hurl a spud more than 100 meters max with the setup you have right there. Very nice build though! And ditto about the sprinkler valve. Or better yet, build yourself a piston valve!

Maybe he means millimeters lol
Looks pretty good man. Like the setup.

great cannon, i assume its not your first because it was a cannon built on request. he might be able to get 200m+ with super modifyed SV in conjunction with that huge barrel.

its my 4th cannon and acording to my physics teachers mathe it has a theoretcal range of 1400m

Yeahh that is probably wrong... a high powered piston valved mega cannon might make it 600m

it has a theoretcal range of 1400m

With an aerodynamic dart, yes. With a potato, probably a 5th of that.

Anyway, nice cannon. Although people say ball valves are slow to open, which they are, you do have a long barrel which helps counter that. If you could spring activate your ball valve, you could increase performance by quite a bit. Are all your pipes and fittings pressure rated?

we used 2d kinematics after i got the muzzel velocity from another spudfiles member he used the pressure (70PSI) multilied by the area and came up with 118m/s as th muzzel velocity and it seemes logical.


i hit a house 3 streets over at 60 psi (i live in a residential area so i have no safe place to shoot it so i may not be abole to get a video this week)

Well, 3 streets away aint no 1400 meters.

we used 2d kinematics after i got the muzzel velocity from another spudfiles member he used the pressure (70PSI) multilied by the area and came up with 118m/s as th muzzel velocity and it seemes logical.
i also appreshiate the suggestions about the other valve types, i have had some problems/frustration/breaking of diaphram valves on other cannons (did not exceed pressure rating)


i hit a house 3 streets over at 60 psi (i live in a residential area so i have no safe place to shoot it so i may not be able to get a video this week)

Dude you just posted the same exact thing except for one sentence.

With a ball valve, your muzzle velocity is about 350 feet per second (80PSI). As for range, about 900 feet. So about 280m, which is actually what I guessed

MrCrowley wrote:With an aerodynamic dart, yes. With a potato, probably a 5th of that.

By the way, I'm using a program called GGDT. Search the forum, Spudwiki or Google to learn about it.

i hit a house 3 streets over at 60 psi

People like you shouldn't be building spudguns. Don't post crap like that on the forum again or you will be banned. It is because of stupid acts like this, that spudguns will be made illegal in the US.

Try spring loading the ball valve. It should be easy enough.

People like you shouldn't be building spudguns. Don't post crap like that on the forum again or you will be banned. It is because of stupid acts like this, that spudguns will be made illegal in the US.

Quoted for completeness. Pay attention to this and choose a more appropriate target next time.

Not that you care if they get banned in the US, Mr. NZ

Yeah but seriously don't be shootin' houses. Not cool. Nobody wants mashed potatoes on their windows.