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Homade Solid Propellant Cannons


Zeppelin

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Here is a 6" cannon i made in metalwork last year

http://www.freewebs.com/jonny2940/Picture%2023.jpg

The hole is about 1\4" wide and 3" deep. The mount is some cut angle iron, spray painted black. (there is a nickel there for size referance)

 

It was made out a a solid steel 1"diameter bar. I turned it down on the lathe and drilled the hole down the barrel then polished it up. I am planning on drilling a hole near the back of the chamber for electric ignition in the future. I think that i will use BP as the propellant and some 1/4" steel rod chopped up into 3\4" peices and grind the ends so they are half-round as ammunition.

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That looks very nice indeed. It is similar to one I am going to make, although mine will fire 8mm ball bearings and be made of brass. Probbably wont taper as much either. A teacher at my school made one to fire golf balls, its insane.
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Attached is my handy idea for ignition. You put about 2 9V batteries in the base, then you attach a switch and attach them to electrodes drilled into the barrel on either side, the electrodes have a hole, and are insulated from the barrel. You thread nichrome, or any other high-resistance wire though here, load it, and press the button to fire. This would be more simple than mass-producing E-matches, and there would be little wasted gas from blowing out the remains of your x-mas ignitors. Something that I would impliment on my cannon.

 

Very ugly drawing, I may redo it later.

post-11-1140460331_thumb.jpg

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The main problem that i can see about this kind of cannon design is the buildup of ash\residue in the back of the barrel. Does anyone know what kind of low power explosive would not leave very much residue? Or how you could clean the barrel?
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Is it stainless, or regular steel? The residue from BP is mostly potassium carbonate, with some other salts. If it is stainless, some water and scrubbing would be fine.

 

Otherwise, I suggest you keep some 1/4in metal bar, and simply put it in a vise, or ram it, such that it knocks and scrubbs the rest of the stuff off.

 

Nitrocellulose is a clean burning propellant.

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Its regular steel. If i cleaned it that way, Wouldnt the residue get jammed up against the back and be difficult to get out?
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Nitrocellulose leaves almost no residue. However it detonates under pressure so you will have to be VERY carefull on how much you use. Sam Borrows from PowerLabs used and cobination os nitrocellulose and some other chemical to power his golf ball cannon to supersonic speeds.

 

Nitrocellulose come it three bases. Its the triple base type you want to use I think. IIRC ping pong balls are made with the double base type. Try burning one as watch how clean it burns. Triple base is even better!

 

I think you should experiment with 0.05g and get bigger from there.

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"Nitrocellulose is a clean burning propellant"

 

While Nitrocellulose burns leaving very little trace residue, the gases from it decomposition (as are those of black powder) are corrosive and will attack the metal your cannon is made from; use a double base powder (like rifle powder) and you will have less problems with residue and corrosion.

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That is a beautiful cannon Zeppelin.

 

FYI, for all those looking to make/machine golf ball cannons, automobile muffler pipe is easily had in the right dimension and will withstand moderate BP loads (10g) without any problem. ;)

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I have a nice salutecannon in my backyard, and it is made from solid steel, and I'm thinking to try a shot with it. It's about two feet long, and has an ID of 1". My problem is just to find something to shoot out of it.
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  • 4 months later...

Heres mine I made about 5 years ago in woodwork. The barrel is one piece and can pivoted up and down. Ive fired it twice once with NC the other with some green mix. NC was much better and alot cleaner obviously i took the photo before firing it. Used a marble as a projectile and ball of aluminium foil. Oh and its barrel length is 19cm and its about the size of my hand

~Edit resized pic~

post-11-1153403109_thumb.jpg

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lol canon made of wood, not something you see everyday you should line the inside with some metal pipe im sure it would be less damaging to the wood
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Actually the wood holds up very well after I drilled to hole I ran a blunt drill bit inside it so it kinda polished the wood giving it a bit more protection
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For gods sake DON'T use nitrocellulose for propellant in that metal-barrelled gun (or that wood one), unless you have a means to accurately measure chamber pressures.

 

Use a bit too much NG, or have a bullet a bit too heavy, and you now have a hand grenade on wheels.

 

Use BP. it's much more forgiving. In fact, you CAN'T overcharge that gun with BP. Put in too much and it simply doesn't get a chance to burn while still confined. The "bullet" will leave the gun before the powder finishes burning.

 

This method is still used by a lot of muzzleloading shooters. I did it too. Simply put, go out over fresh snow, load weapon with a purposely underweight powder charge, shoot (with barrel perpendicular to ground if at all possible). Look on snow for UNBURNED particles of BP. If there are none, increase subsequent powder charges until you DO see unburned powder, then back off about 5 grains. You now have the optimum powder charge for the barrel length, bullet weight and powder. I used 1Fg and 2Fg powder. It's accurate enough for any hunting purpose, but target shooters prefer chronographs for some reason. ;)

 

M

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Dont worry I only used about a 1/4 of a cotton ball worth and its all puffed up with a loose fitting marble. Im not going to do anything dumb and jam an aluminium slug down the barrel and load its full of BP or NC. I really only fired twice it to see if it would work haven't used it since.
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Pont,

 

How do you *KNOW* what your chamber pressure was, even using what you believe to be a "safe" load??

 

For all you know, your load could have been near the point of bursting the barrel. And I guarantee you, a pressure that's fatal to the barrel (and maybe bystanders) will be reached LONG before you "load it full" of any NC based propellant.

 

That's why I suggested staying with BP. It's a hell of a lot safer, and assuming the barrel steel isn't flawed and your projectile is shaped to prevent its jamming in the barrel when fired, you really CAN'T overload it.

 

Of course, if you have degrees in Chemistry (specializing in propellants) and Gunsmithing or Metallurgy, well never mind then. Play away.... :D

 

M

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  • 1 year later...
Here is a 6" cannon i made in metalwork last year

 

The hole is about 1\4" wide and 3" deep. The mount is some cut angle iron, spray painted black. (there is a nickel there for size reference)

Dude i made something like that at my school last year too but because my friends was being $@^&heads they told the teacher i was going to make it shoot marballs ( i was ^_^ ) so he drilled holes in the bottom of it <_<

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  • 4 weeks later...
hand grenade on wheels.

LOL. I just thought it was funny b/c a hand grenade is meant to be thrown not put on a skateboard and rolled.

 

 

Dude i made something like that at my school last year too but because my friends was being $@^&heads they told the teacher i was going to make it shoot marballs ( i was 2happy.gif ) so he drilled holes in the bottom of it dry2.gif

 

That blows. You should have kept it and made a plug out of a dowel and wood glued it in there.

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Just load in more BP, it will fire as hard as with no holes, but will not recoil that badly as normal since it has a ""recoilless" system now. At least that is what I think..
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Nitrocellulose leaves almost no residue. However it detonates under pressure so you will have to be VERY carefull on how much you use. Sam Borrows from PowerLabs used and cobination os nitrocellulose and some other chemical to power his golf ball cannon to supersonic speeds.

 

Nitrocellulose come it three bases. Its the triple base type you want to use I think. IIRC ping pong balls are made with the double base type. Try burning one as watch how clean it burns. Triple base is even better!

 

I think you should experiment with 0.05g and get bigger from there.

Real double base NC has nitroglycerine in it. Definitely not something you want to be firing in a homemade gun.

 

Ping pong balls, if they actually are NC, are NC mixed with camphor to plasticize.

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