Worlds Largest Combustion PVC Cannon?

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Engineer87
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Sun Oct 12, 2008 1:18 pm

Hello, this summer I finished a PVC cannon that I believe may be the worlds largest in the category of Combustion PVC Cannon, but I'm unsure of this so that's why I came here. The barrel is 8" X 5' and the chamber is 10" X 3'. I made a video about the whole thing.



If you watch it definitely watch it in high detail.

My first question is, does anyone know of a Combustion PVC Cannon bigger than mine.

Second would be if there is none, I would like to pursue a guinness record, but the legality issues concern me. What are the laws and what are my rights with something like this? I live in Illinois.
Last edited by Engineer87 on Sun Oct 12, 2008 1:30 pm, edited 1 time in total.
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POLAND_SPUD
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Sun Oct 12, 2008 1:25 pm

it looks great... however I think that PVC might be too weak in such large size.... have you ever thought of making it from steel ? (yeah I know it would be really heavy)
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Spuddin
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Sun Oct 12, 2008 1:26 pm

its a cool cannon, u should build a carriage with wheels to look like a small howitzer. btw there is a basketball cannon on here somewhere so i would rename the title. good job on the gun.
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mark.f
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Sun Oct 12, 2008 1:28 pm

I know a few cannons of the same bore size, but not the same volume.

Also, I would suggest some sort of mixture fan, because a chamber that size takes a while for all the fuel to diffuse enough to get a good ignition.
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Ragnarok
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Sun Oct 12, 2008 1:49 pm

Engineer87 wrote:My first question is, does anyone know of a Combustion PVC Cannon bigger than mine.
How are we defining largest combustion? This has a total volume (of both chamber and barrel) of a little over 150 litres.

Yours is, from your dimensions, a bit less than 100 litres, meaning Gort's cannon is considerably larger. So really, although yours is longer overall, I wouldn't call it the largest. (It's also worth noting that longer cannons than yours have been made).
Does that thing kinda look like a big cat to you?
SEAKING9006
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Sun Oct 12, 2008 1:59 pm

It's definitely not the biggest, and I think by biggest you mean bore diameter. 'Biggest' would really entail that the entire cannon would take up the largest total volume of any cannon. If I could build combustions, I would probably take a crack at making the biggest, but that would mean I had found some way to transport, store, and shoot it without breaking laws.

If you wanna go for biggest, try doing that again with multiple chambers, a longer barrel, multiple spark gaps, and a mount. :wink:
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Engineer87
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Sun Oct 12, 2008 2:08 pm

Ragnarok wrote:
Engineer87 wrote:My first question is, does anyone know of a Combustion PVC Cannon bigger than mine.
How are we defining largest combustion? This has a total volume (of both chamber and barrel) of a little over 150 litres.

Yours is, from your dimensions, a bit less than 100 litres, meaning Gort's cannon is considerably larger. So really, although yours is longer overall, I wouldn't call it the largest. (It's also worth noting that longer cannons than yours have been made).
We'll thanks for answering my question then. Since there are longer and/or bigger cannons then that leaves a lot of gray lines that I don't like. I guess I could still apply for a record simply because I haven't found an existing one, but that's a hassle I don't want to go through especially since there are bigger cannons out there. Also notice that the title is "Worlds Largest Combustion PVC Cannon?" I'm presenting this as a question rather than actually calling it the largest. And if your talking about the video, we'll it's just a video.

@ POLAND_SPUD
PVC is strong enough but the deformation during the firing causes a problem. The cap blew off once on the new gun, but the threads on both pieces where in perfect condition afterwards. So I will be putting steel hose clamps all around the female adapter to spot this deformation.

@ markfh11q
A mix fan would help on the mix time, but it already takes a few min. to prepare it for firing, the seconds we would save by adding a fan just aren't worth the work to us right now.
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Ragnarok
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Sun Oct 12, 2008 2:12 pm

Engineer87 wrote:the seconds we would save by adding a fan just aren't worth the work to us right now.
It's not just seconds saved, it much improves power, efficiency and reliablity.
Does that thing kinda look like a big cat to you?
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Sun Oct 12, 2008 2:30 pm

Mother of god... that's a hugggeee bitchhh!
Engineer87
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Sun Oct 12, 2008 4:22 pm

Ragnarok wrote:
Engineer87 wrote:the seconds we would save by adding a fan just aren't worth the work to us right now.
It's not just seconds saved, it much improves power, efficiency and reliablity.
Power isn't a concern just yet, but if it is mapp gas will be used instead of propane. If more power is needed after that then we'll use a fan. And reliability hasn't been a problem. The gun had problems firing when the spark was in the side, but we found out that the gas sinks, and putting the spark in the cap took away the ignition problems.
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ammosmoke
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Sun Oct 12, 2008 4:25 pm

That is awesome!! But the barrel looks a wee bit short.
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starman
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Sun Oct 12, 2008 4:28 pm

You could have helped yourself out a bunch by putting the spark gap (or 1 or 2 more) in the center of the chamber and yes, a mix fan. I know you said it wasn't worth the effort, but....you should never have to hold the sparking device down for seconds before ignition. This actually makes the cannon less safe. With a little extra effort, this thing could be "dialed in" from the get go, firing with the initial spark first time, every time. MAPP gas will offer about 10% more power at the most, probably more like 5% in your configuration.

However, it is fun to watch the beast being shot!! .. :wink:

Also, D_Hall is working on Pipe Dream which will require a semi trailer to haul.
Last edited by starman on Sun Oct 12, 2008 4:41 pm, edited 2 times in total.
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mrbadexample
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Sun Oct 12, 2008 4:29 pm

no power, it's tossing a few chunks of wood. no velocity, you can watch the few chunks of wood in flight. no balls, it doesn't "kick", but nobody will hold, aim, fire it.

it's a big ZERO, it's big, barely functions, nothing special. howard hughes made the "spruce goose", it was large, it flew a little, did nothing else. congratulations on "spruce goose 2".
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starman
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Sun Oct 12, 2008 4:37 pm

mrbadexample wrote:no power, it's tossing a few chunks of wood. no velocity, you can watch the few chunks of wood in flight. no balls, it doesn't "kick", but nobody will hold, aim, fire it.

it's a big ZERO, it's big, barely functions, nothing special. howard hughes made the "spruce goose", it was large, it flew a little, did nothing else. congratulations on "spruce goose 2".
Gee MrBad, think you could be a little more encouraging? I've seen many more cannons that don't measure up to this thing. There's more to making this big thing work than you might think. It's not by any means an optimal cannon, but a ZERO it ain't... :roll:
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ammosmoke
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Sun Oct 12, 2008 4:46 pm

I would try for a barrel of smaller diameter, and make it longer.
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