Pump action Cartridge Potato Cannon

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CannonCreations
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Fri Aug 09, 2013 10:12 pm

This is just my first prototype into this kind of idea. This cannon uses cartridges that are filled with whatever I want, and then clipped onto the side of the cannon. These cartridges are 4" long and 1.25" in diameter. The cannon itself is just a regular 2" piston valve cannon, that I have used for other demonstrations in the past, including the remote control golf ball cannon that I posted a week or two ago. The barrel is the only newly designed part.

It uses a 1.25" barrel sleeved inside of a 2" pipe. I found that if there is a coupling around the barrel, that it is a perfect fit inside of a 2" pipe. There are two slots cut out of the 2" pipe, one that allows a cartridge to be put in, and one that allows it to fall out. In the back of the pipe, I have a floating piece of 1.25" pipe with half of a modified coupling that grabs onto the cartridge. There is an o-ring inside of coupling that presses up against the cartridge to keep a full seal against the face. There are two springs attached to the floating catch, that keeps a steady 23 lbs of force on the back of the cartridge at all times.

The front part of the barrel, the part that is attached to the pump has the same kind of coupling design on it as well, except there are no springs, and the coupling is a little deeper, this is why the cartridge only sticks to the barrel, and not the rear catch.

There is an ejector built into the top of the 2" sleeve that catches on the ridge of the cartridge and dislodges it from the barrel, and drops it out of the sleeve.

A new cartridge is then loaded, the barrel comes back and pushes against the rear catch. The pump handle is then turned to lock the barrel from sliding forward.

I have a video here of the trial run of my first cartridge cannon

[youtube][/youtube]

Please feel free to offer suggestions, just refrain from pointing out the primer stains, I already know about them.

Feel free to ask any questions and I will do my best to answer them
Last edited by jrrdw on Fri Oct 18, 2013 9:46 am, edited 1 time in total.
Reason: Fixed video.
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jrrdw
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Sat Aug 10, 2013 5:25 am

How much room for ammo in the cartridge? A feed tube would make it that much nicer.

All in all that's a nice build, congrats. :D
CannonCreations
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Sat Aug 10, 2013 12:29 pm

Each cartridge is 4" long with a diameter of 1.25" so it can fit a good portion of most spuds, I would like to come up with some new heavier more destructive ammo for it though
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Sat Aug 10, 2013 2:00 pm

That's cool! Well done.

It seems a bit clumsy with a crazy length of pull though, but I dig the concept.

Tube fed, that's that next step man. Or even a box or gravity feed. Get to it! :)
CannonCreations
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Sat Aug 10, 2013 2:07 pm

Thanks, and yeah I agree on both accounts, it was just a concept to see what I could do. I have been wanting to add some sort of tube fed, or gravity fed, but i have run into some problems there. When there is one cartridge on top of the cartridge in the barrel, the ridges of the two lock, and keep the barrel from being able to slide forward. I think that if I want to make it reload itself, then I will have to do away with the ridges, and then that completely changes the design. I have tried making it tube fed, and actually had something that kinda worked, but it was too unreliable and made the whole thing messy, so I did away with it.
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Sat Aug 10, 2013 2:18 pm

Ah okay.

That's a classic problem with rimmed cartridges in general - here's how to properly load a stripper clip in the ubiquitous Mosin-Nagant rifle; would this help your design at all?

Image
CannonCreations
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Sat Aug 10, 2013 2:30 pm

It is a good idea, problem is, is that my cartridges have two rims. This will give me something to think about though, thanks
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Sat Aug 10, 2013 2:37 pm

Oh, ok. Can you snap a good picture of one of your cartridges?
CannonCreations
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Sat Aug 10, 2013 2:49 pm

ok, here is a picture of the cartridge in the cannon
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This is a picture of the cartridge in the barrel
This is a picture of the cartridge in the barrel
here is a picture of the cartridge with the barrel locked, part of the cartridge is actually hidden inside the 2" sleeve
here is a picture of the cartridge with the barrel locked, part of the cartridge is actually hidden inside the 2" sleeve
Last edited by CannonCreations on Sat Aug 10, 2013 2:58 pm, edited 3 times in total.
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Blitz
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Sat Aug 10, 2013 2:50 pm

Not showin' up. :(
CannonCreations
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Sat Aug 10, 2013 2:51 pm

yeah sorry had to fix it
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Blitz
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Sat Aug 10, 2013 2:53 pm

Ah ok, there we go. I see what you mean now.
CannonCreations
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Sat Aug 10, 2013 3:03 pm

Yeah, I have been trying to figure something out. The best I could do, was to stick a 2" pipe at 45° to the opening and have gravity feed sequential cartridges. I found this to be unreliable, and scrapped the idea. I also wanted to stay away from anything overly complicated
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Tue Sep 17, 2013 8:53 pm

I hope you don't mind if I reserect this thread, I'm not a very frequent visiting member but I'm very interested in this cannon.

I love seeing new cartridge ejection system, there are just so few of them out there, CannonCreations you may be interested in checking out my old creation http://www.spudfiles.com/forums/deus-ex ... t7723.html it does have it's flaws such as the massive dead space created by the bolt mechanism which you did much better by having the barrel slide rearward

the rims of my cartridges were made of entire pressure rated couplers so I never had trouble creating a magazine besides getting a good magazine spring

do you think you could just use full repair couplers at the rear of the cartridge and taper the sections where the barrel and cartridge interlock?
CannonCreations
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Tue Sep 17, 2013 10:44 pm

I never thought about that, but yeah I do suppose I could modify the design slightly to accept a different kind of cartridge. I wish I would have seen your system earlier, because now seeing this I have a new idea as to how to work my design. I wont be able to even touch a cannon for awhile though. I'm in college right now but I will hopefully get a chance to do some cannon stuff this December. I hate being away from the basement this long, although I get to use some really cool stuff here, 3D printers, CNC's, machine shops, etc. I also have the chance to use the universities pneumatic cannon. 14,000 psi of air!!!!!, yeah, the thing is crazy. I've also been thinking about building a hybrid, but I am always looking to improve on older designs. If you have any questions or comments feel free to message me, I still get on daily to check on everyone.
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