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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.
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saefroch
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Sun May 08, 2011 9:34 pm

Rocket nozzles have a bell shape to take advantage of the effects of a DeLaval nozzle (which I'm sure you're aware of). There is a world of difference between rocket exhaust and the muzzle blast from a pneumatic.

With a larger barrel, velocity would be less, mass of the expanding air the same, less recoil. If you care to throw some numbers at it, I'll even get you started:
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EDIT: Plugging in numbers for this build gives me only 185m/s exhaust velocity, actually less than SOS, which we normally assume in recoil calculations.
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Jimmy K
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Sun Jul 31, 2011 2:45 pm

I am sorry to say that my cannon has been confiscated. It was awesome while it lasted. Big bangs and even bigger recoil...
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mattyzip77
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Sun Jul 31, 2011 3:48 pm

awwwww man, that blows!!!! what happened??? whats the story????
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Gun Freak
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Sun Jul 31, 2011 3:49 pm

:shock: :shock: :shock:

Full story?
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Technician1002
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Sun Jul 31, 2011 4:34 pm

What are the chances of getting it returned? There may be an appeal process. What did you present it as? Pumpkin cannons are legal. It is a Corn, Grapefruit, Cabbage, Squash, Pumpkin cannon isn't it?

Plenty of people have pumpkin cannons in the smaller sizes.
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Unless you are doing dangerous stuff and endangering the neighbors, there should be no reason for it to be confiscated.
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Jimmy K
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Sun Jul 31, 2011 4:54 pm

It was taken away from me on a noise complaint. The guy cited some township ordinance.
(That should give you an idea of how loud it was - I live on a 40 acre farm away from everyone)

There's a good chance that it'll be given back to me. I kinda cheated them anyway.. I knew they were coming so I took off the valves and all the valuable stuff. They took the trailer, tank, and barrel. I still have the compressor, valves, hydraulics, and controls.

Hopefully I can resolve it with the "neighbor" and not get the township involved. My other neighbor didn't mind at all...
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Gun Freak
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Sun Jul 31, 2011 5:01 pm

Hah... way to go! Save all the expensive stuff! 8) I hope you can get it back man!
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MrCrowley
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Sun Jul 31, 2011 5:28 pm

It's ridiculous that you get your cannon confiscated when you live on a 40 acre farm in America and I live in an affluent suburb in the city with 10 houses within 30m of mine, some of which have young children, and I've never had a complaint.

I probably should refrain from firing my larger cannons at home in the future, considering I can face jail time.

Well done with saving the important components.
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velocity3x
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Sun Jul 31, 2011 6:16 pm

Jimmy K wrote:It was taken away from me on a noise complaint. The guy cited some township ordinance.
Sounds to me like they're jerking you around. If a person drove through town with a defective car muffler, would they confiscate the car? Hell NO......they'd issue a warning or maybe a ticket for violating the noise level ordinance but....they surely wouldn't confiscate it!
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mattyzip77
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Sun Jul 31, 2011 6:43 pm

that is such friggen bullshit!!! your on your own 40 acre private property and they took it away?? that sucks dude!! Keep fighting it and i bet you will get it back!!
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saefroch
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Sun Jul 31, 2011 8:01 pm

Jimmy K wrote:Hopefully I can resolve it with the "neighbor" and not get the township involved. My other neighbor didn't mind at all...
The Coase Theorem. I like.
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jackssmirkingrevenge
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Mon Aug 01, 2011 12:18 am

MrCrowley wrote:I live in an affluent suburb in the city
Listen to you, posh boy :P :D

Jimmy, BOOOOOOOOO! to your neighbour!

Might I suggest some noise abatement measures for future development:

Image

Image
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Jimmy K
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Fri Jan 06, 2012 7:58 pm

Hello everyone. It's been a few months since my big cannon was confiscated and since my last visit to this site. I apologize for not returning to answer questions in due time.

Unfortunately, I have since sold my cannon trailer and some other supplies, but I have drawn up plans for some cool stuff to build this summer.




A smaller version of this cannon is in the works. The barrel has been halved - to 10' - and the sprinkler valves are now pilot valves. 4" piston valve, here I come.

With the smaller barrel size, less supports will be needed, so I will attempt to do 180 degree horizontal movement and 90 degree barrel angle movement like my original plans.

Another exciting prospect is a rifled barrel. I've made some great connections at the University of Alabama and we've been throwing around ideas about rifling a snug bore softball cannon. We think we can work something out.



Also I'm working on founding a group I call Crimson Cannoneers - a university sponsored student group working on ballistics, cannons, etc. With lots of money from dues and the university, some really cool things can be cranked out of this club.



Stay tuned for some cool non-cannon related projects too. I'm currently building a sweet turbojet powered go-cart and some random things.
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evanmcorleytv
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Fri Jan 06, 2012 8:13 pm

Also I'm working on founding a group I call Crimson Cannoneers - a university sponsored student group working on ballistics, cannons, etc. With lots of money from dues and the university, some really cool things can be cranked out of this club.
May I be part of that? I'm good at it!! lol, and I have my mauler cannon finished, I just have to wait for my mauler repairs to be finished.. so in about a week or two, I will be shooting golfballs upwards of 600 FPS.
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Daltonultra
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Sat Jan 07, 2012 12:57 am

velocity3x wrote:
Jimmy K wrote:It was taken away from me on a noise complaint. The guy cited some township ordinance.
Sounds to me like they're jerking you around. If a person drove through town with a defective car muffler, would they confiscate the car? Hell NO......they'd issue a warning or maybe a ticket for violating the noise level ordinance but....they surely wouldn't confiscate it!
Local noise ordinances don't apply to a car's exhaust note in most states. As long as your car complies to state and federal laws concerning emissions, and whatever STATE vehicle-noise laws you might have, your town can't say a thing about it. Stereos and other noise-makers that don't have to do with the drivetrain are a different matter.

Here in Ohio, as long as you have a muffler, it's legal, with the exception of "glasspack" type aftermarket mufflers, which are banned from street use in Ohio.
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