Corn Cannon

[BigDeutcher]

Recently took the kids to a corn maze and low and behold they had a corn cannon and being boys they now want one.

It was pretty cool firing 1/3 of cob at targets 75 to 100 yards away.

So to make the long story short, looking for plans to build a corn cannon using a propane tank, safety switch and piviting swivel base, any help would be greatly appreciated.

Tried the search engine and had limited success.

Awesome site, really liked the gatling auto paintball gun!

[Gippeto]

They have corn in NS Thought it was just corny folks.

You sure you want the propane tank? Or do you want to power it with propane? That could work too.

Chamber/valve/barrel trigger on a swivel, charged/fired using a 2 postion 3 way valve from Princess Auto and quick connected to a compressor?

[BigDeutcher]

No it was neumatic, pretty sure they were charging into the propane tank as they had two set up and the air house were running from a utility shed into the tank and back out to the cannon.

[BigDeutcher]

Oh yes, we have corn in NS, lol. Lots of corn and when we run out of that we will go to PEI and use there spuds.

[Gippeto]

Might find a spud or two there for sure.

Are you thinking metal or pvc construction? Want to stick with an electrically activated valve?

This site isn't really about "plans" per se, but you'll find a ton of ideas in the showcase sections, and folks are generally willing to answer questions and give the odd nudge in the right direction.

The corn cannons I've seen were fed by a hose to an Asco diaphragm valve which was activated via solenoid...ie electric. Ebay can be a source of these for a good cost savings.

Valves intended for sprinkler systems (sprinkler valves..duh! ) can be had at Home Depot or similar...they typically use 24vdc, but are easy to modify to use an air compressor blowgun for activation as well.

A larger qev (quick exhaust valve) is another off the shelf option if you can find one...3/4" would do for a corn cannon.

Tank feeds valve via large hydraulic hose, which feeds directly into "cannon" (reducer and piece of pipe).

Better IMO would be to have the tank mounted directly to the valve as well as the barrel...mount the whole thing on the swivel and only need to hook up an air line.

[BigDeutcher]

Okay that sounds like a place to start. Thinking metal, more for safety than anything else and electric solenoid(s), will probaly have to build two knowing these two they will want to be shooting at each other vice being competitive and knocking down targets lol. Thanks of the help ... time to start sourcing parts.

[dart guy]

im here i am the guy to ask for plans, if its easy.you could always have a setup like a piston pnematic. this corn cannon how big do you want the barrel to be? like 1.5 inches if so using pvc would be the best idea because unless you build a fridge compressor your probably not going over 180 psi and 2 inch pvc holds 350 psi as a limit(scedual 40 pipe) so if you make that the chamber your in the green.gimme about 10-20 minuts and i will post a plan jsr if your there please point out my flaws....... in the desine.
edit: as promised here are your plans
if you have questions please ask i will explain it if someone doesent beat me to it.

[Gippeto]

im here i am the guy to ask for plans,

Uh huh...


2 inch pvc holds 350 psi as a limit(scedual 40 pipe)

Ummm...no. Chart is about half way down and gives max working pressures. Would not use pvc past 120psi, but that's me.

http://www.harvel.com/technical-support ... chedule-40



if you have questions please ask i will explain it if someone doesent beat me to it.

Explain the pipe/hose running from between the ball valves to the chamber? Is it commonly considered to be good practice to thread through a single layer of pvc?

Should one perhaps know how and why something works before attempting to explain it to someone else?

[Technician1002]

My 2 cents. I've been on some football fields and I have been on some corn fields. I've loaded hay trucks. Unless those are 1 ton bales and those are 500 lb pumpkins, the distance in the OP photo is closer to 35 yards.

That cannon mounted on the post is a commercial product sold to farms who have corn mazes and are limited in power. Youtube has several videos of them in use. Google the cannon videos.

Sample video of that model in use from a quick Google search.
[youtube][/youtube]

Not sure why, but can't get the video to load poperly in Spudfiles today.

In another video I just watched, they spec the range at about 200 feet or only 67 yards.

[Gun Freak]

Dart guy... Please refrain from posting plans you drew in 60 seconds with Paint, especially when you don't even know if it works (FYI it won't and you're not even close).

Gip pretty much already took care of this one... I would suggest a dust collector valve or if you're ambitious and handy, a 2" piston valve. With a good valve you can get away with a smaller chamber which is good if you're mounting it on a stand...

Honestly metal is overkill, you can use a short length of 2" PVC which is rated to 280 psi. You shouldn't need more than 60 psi with this gun anyways.

[BigDeutcher]

So a basic synopsis of a generic pneumatic spud gun would be like the image below the only difference being the actual build?



So i guess I do have a question in regards to the barrel, using a piston / wad and making it reusable/ retained in the barrel is that feasible or as in what I would like to make the Cob Cannon, will the corn cob be sufficient as a wet wad fit that the pneumatic air pressure wont destroy the cob before it exits out barrel?

Thanks for all the help so far, i realize the project can be as varied as the minds imagination but there has to be certain principals that need to be adhered too in particular safety. I see it in my head how there set up was done, tank being the source, the propane tank being the accumulator filled to a supply line regulated more or less probably at the air source, the breech / ball being the electric switch actuated by a the trigger. wondering if a rifled barrel would improve accuracy (saw a site that sold rifled pvc barrels)?

[Gippeto]

That will work, but you may have to do some tweaking to the acculmulator and regulator setpoint to get the actual performance level you're after...only you know what you want your kids playing around with.

Couple points;

Would recommend a valve between the regulator and accumulator...a bit more involved for charging, but will save you some air, and give the gauge on the regulated side some protection from being hammered with the rapid pressure drop.

The corn cob should work fine as its own sabot/wadding.

I would not bother with a rifled barrel as the projectile itself is not going to be truly centered, and likely will not be ballanced enough to make rifling of any help.

Lob away...have a sh1t load of fun doing it.

[BigDeutcher]

Only reason I mention the rifled barrel was thinking of a swap out barrel for actual spudding when I run out of cobs. I understand your point of isolating the two gauges. Makes sense. Thanks.

[dart guy]

i ment that i will post plans if they are wanted .and that funny tube would be for equalizing the pressure between the chamber and the space behind the piston, but i forgot a ballvalve and i didnt place a set of lines on top of it because i think the pics are to small to see renforcements like a coupler but im sorry giving ideas to those with money.(ps i dont got enough cash to build anything yet ) sorry mods i did ask for it though. i always try my best to help out though.

[Labtecpower]

If you would have drawn it like this it would work;



(assuming you got the piston length right)

As people mentioned before, only give information about subjects you know well. You're playing with high pressures here, things can get dangerous with improper constructions.. as I experienced in person