The Offical Spudgun Thread

[Event]

This thread is for the discussion of Spud Guns.

This spring break, I should be building two more spud guns, even more advaced than my last one.

The first one will be a standard spud gun, but with some minor improvements. We will put a fan in the chamber, which will increase muzzle velocity by about 25%. Im also going to see about getting better ignition system, maybe using a 60,000V stun gun. That may be a litte too expensive, though. I will also add a handle or two with a gun-like trigger. The barrel will be about 3 feet long, 1.5" in diameter and it will be rifled, which improves accuracy. I wil also make sure that the barrel is exchangeable and removable. We can then experiment with different sized barrels. It will also be easier to transport.

Our second one will be a little stranger. We will fit it with a 2.5" diameter barrel, which is the perfect diameter to shoot tennis balls, which was our original intention. But we are going to try to work out a way to automatically reload, with a tennis ball magazine. I will post plans when we make them.

Stay tuned for updates.

Go ahead. Comment.

 

[69Dodge_Charger]

I really don't know much about these cannons, but for the automatic reload on the tennis ball cannon you could do a gravity feed much like this:
http://img114.exs.cx/my.php?loc=img114&image=untitled3wa.png
I don't know what you had planned for the gun or if you have another method of automatically reloading the tennis balls, but I just thought this might help. It really depends on how big you want the cannon though.

 

[Event]

I really don't know much about these cannons, but for the automatic reload on the tennis ball cannon you could do a gravity feed much like this:
http://img114.exs.cx/my.php?loc=img114&image=untitled3wa.png
I don't know what you had planned for the gun or if you have another method of automatically reloading the tennis balls, but I just thought this might help. It really depends on how big you want the cannon though.

Well, my friends say that they have an idea, but I haven't had a chance to really communicate with them at the same time on this. We will get together to have a meeting ASAP.

 

[PS]

Do it the redneck way dude. Get

1. 6 feet of 3'' PVC piping with endcap
2. 2 litres of Ether
3. a drill
4. barbecue ignitor
5. potato

Take Item #1, and drill into it 4 holes into the side of the pipe about 1 foot up, evenly spaced around the pipe. Think 12:00, 3:00, 6:00, and 9:00. Then, drill another larger hole down near the bottom of the pipe (just above the endcap, or if you like, in the endcap). Insert the barbecue ignition into that hole, with the mechanism and wires etc inside the pipe. Fill with ether. stick potatoe in. Push button. Send potatoe approx. 600ft through the air.

 

[Minnesota01R6]

I have made a few of these, and I would say ether is a great propellant. I used the black ABS instead of PVC pipe because it is able to handle more PSI. Once I got the ether mixture correct I started blowing the endcap off the gun. (it takes a very small amount - any more and you get less of an explosion). You can get ether at any auto parts store - they sell 100% ether as starter fluid in a spray can.

My next spud gun will be pneumatic. A friend has a 300 psi air compressor that should work nicely. There's also a guy on the net shooting cement-filled aluminum (or aluminium) cans. He has a formula for getting the best length of your barrel based on the size of your combustion chamber.

 

[Event]

I have made a few of these, and I would say ether is a great propellant. I used the black ABS instead of PVC pipe because it is able to handle more PSI. Once I got the ether mixture correct I started blowing the endcap off the gun. (it takes a very small amount - any more and you get less of an explosion). You can get ether at any auto parts store - they sell 100% ether as starter fluid in a spray can.

My next spud gun will be pneumatic. A friend has a 300 psi air compressor that should work nicely. There's also a guy on the net shooting cement-filled aluminum (or aluminium) cans. He has a formula for getting the best length of your barrel based on the size of your combustion chamber.

The black ABS pipe is not as safe as the PVC. It has a cellular core, which basically means the pipe is hollow. Very dangerous.

We used hairspray first time around, but that gummed up the whole system. We will try starter fluid this time.

 

[PS]

You can use butane gas as well, if you can contain it. that's probably where the endcap comes in handy if you can get one that screws onto the bottom. Heck, my dad has blown barbecue lids clean off the barbecue and hit the house from leaving the butane on for too long.

 

[Event]

You can use butane gas as well, if you can contain it. that's probably where the endcap comes in handy if you can get one that screws onto the bottom. Heck, my dad has blown barbecue lids clean off the barbecue and hit the house from leaving the butane on for too long.

I know you can, but in order for it to be safe, you need a regulator and other complex, expensive stuff. Ether should work fine.

 

[PS]

I think if you bottle neck it somewhere, you can also get like 50% more boost out of it when you use gas. I just forget where though, because it would have to be internal...

 

[Der Alta]

And here's where you're meeting the limits of your propellant and material.

You now need to augment the strength of the PVC. Warning dangerous content ahead. Reading further than this point -> . <- absolves me of any damages you incur.

Duct tape and Denim to reinforce the PVC beyond its failing point. Which means you can increase the explosive nature of the propellant. However, you're getting closer to building a PVC grenade.

Now... Are you ready to take it a step further? The propellant you are using is reaching it's limit. Now you need to graduate to compressed air for a propellant.

Spudzooka plans

Going where very few potatoes have gone before.



AO

 

[GTrackd02]

Oh my! that cannon makes mine look retarded..lol
I made this about 6-7 years ago...
It works ok, i use starting fluid with at least 50% ether in it
Ingnitor is a lantern flint sparker mounted in the endcap, propelent is spayed into the chamber via a small red tube thats is tapped into the chamber (the lil red tube that comes on most lubricant sprays ex: wd-40) 1.5 inch barrel 3 inch chamber...
I made this with no plan and no prints,lol just off the top of my head...
Here are a few pics, dont mind the messy yard..lol

 

[Event]

Oh my! that cannon makes mine look retarded..lol
I made this about 6-7 years ago...
It works ok, i use starting fluid with at least 50% ether in it
Ingnitor is a lantern flint sparker mounted in the endcap, propelent is spayed into the chamber via a small red tube thats is tapped into the chamber (the lil red tube that comes on most lubricant sprays ex: wd-40) 1.5 inch barrel 3 inch chamber...
I made this with no plan and no prints,lol just off the top of my head...
Here are a few pics, dont mind the messy yard..lol

That's essentially what our first one looks like. Very ghetto. Yours has a coler paint job, though. Ours was PVC white! Fired fine, though. I am gonna paint my next on probably black. Maybe with some red on there. Did you use spray paint? Was the cannon sticky at all or anyting like that?

 

[GTrackd02]

That's essentially what our first one looks like. Very ghetto. Yours has a coler paint job, though. Ours was PVC white! Fired fine, though. I am gonna paint my next on probably black. Maybe with some red on there. Did you use spray paint? Was the cannon sticky at all or anyting like that?

Nah It was'nt sticky after it dried.... Like i said I just put it together as I went, It fires damn strong though , folded a metal garbage can lid in half!
The urban camo paint still kills me ugly huh?....l
btw Yes I used regular old spray paint, that was about 6 years ago, I just took those pics this mornin....

 

[ExigeEvan]

I'm gonna try and make one in the holidays.

Is it essential to have a seperate combustion chamber? Or would a simple barrel and end cap work?

 

[Joey D]

The one my car club has is powered by air, we just hook it up to a bagged trucks compressor and blammy. IT doesn't shoot it really far but it does the job.

 

[Event]

I'm gonna try and make one in the holidays.

Is it essential to have a seperate combustion chamber? Or would a simple barrel and end cap work?

You could probably just have the barrel, but you wont get much out of it. It will be very very weak and tough to control. Use a chamber.

 

[PS]

I'm gonna try and make one in the holidays.

Is it essential to have a seperate combustion chamber? Or would a simple barrel and end cap work?

It works best to have an expansion chamber, so that when it does go off it doesn't

1. turn into a bomb
and
2. so that it forces the gases to bottleneck as they move up the tube, increasing pressure, which shoots the potatoe/ball further. And it looks cooler.

 

[ExigeEvan]

They only reason I ask is becasue finding the adaptor bits for whatever size piping I choose might not be easy.

 

[PS]

True, and it can be difficult to ensure a seal and structural integrity of the piping. I know a guy who shot one and all that happened was the endcap blew off in a giant fireball. It was SO awesome!!

 

[Joey D]

Here is a question, can you shoot other things the patatoes? I know a buddy of mine tried to make a watermelon gun at one time and it didn't work out really well.

 

[PS]

You would need a very large diametre pipe with an even bigger combustion chamber and even more bottleneck. I know on Mythbusters they shot a pumpkin through an airplane before.

 

[ExigeEvan]

You could do tennis balls. But there's the expense (You'll want to fire hundreds ) and they'll be abit singed.

Do you guys just dry fit the Piping or use poly cement, hot glue etc?

 

[69Dodge_Charger]

You would need a very large diametre pipe with an even bigger combustion chamber and even more bottleneck. I know on Mythbusters they shot a pumpkin through an airplane before.

I thought it was a chicken.?

 

[PS]

I would imagine rubber cement would work well, but I'd also cover it in a decent amount of duct tape so that if it detonates itself, you at least reduce the amount of shrapnel.

 

[Joey D]

I often thought about pop cans...err soda cans for all you outside of Michigan. Or even soup cans, they would be almost like huge slugs. And yes I would shoot it with in the saftey of a open field.

 

[PS]

I thought it was a chicken.?

They started having "fun" after they shot the chicken.

 

[Event]

You could do tennis balls. But there's the expense (You'll want to fire hundreds ) and they'll be abit singed.

Do you guys just dry fit the Piping or use poly cement, hot glue etc?

PVC Cement, PVC primer, and sandpaper, to ensure an incredibly strong seal.

Oh, and the adapters and bushings are easy to find. They hnave them a Lowe's and probably any hardwar store that sells PVC.

People have fired full 20 oz pop bottles. That requires a very large barrel and very stong propellant.

 

[PS]

I often thought about pop cans...err soda cans for all you outside of Michigan. Or even soup cans, they would be almost like huge slugs. And yes I would shoot it with in the saftey of a open field.

I wonder how high they would go? That would be awesome if they were full!

"Son, can you go run this chicken noudle soup over to gramma?"
"**** that." *BOOM!*
"INCOMMING!"

 

[Event]

I would imagine rubber cement would work well, but I'd also cover it in a decent amount of duct tape so that if it detonates itself, you at least reduce the amount of shrapnel.

Use PVC Cement. Proven effective and safe. Much stronger hold than rubber cement.

 

[Joey D]

Ah that would be sweet come to think of it, I must try it. I could use nitrogen however that seems dangerous as all hell.