Confetti cannon barrel

[bugsingelyn]

I am making a confetti cannon for a St. Patrick's day parade and made a piston valve in a 2 inch Tee with 1.5 inch porting, which I think is plenty for a hand full of cut paper (I should have made it bigger so I can use it after the parade ).

Everything is done, including a CO2 reg. setup, except the barrel, and I have the choice of a 3 inch or 4 inch barrel. We will cut it to size to match the scale of the gun, but hoping it will be the full 10 feet. Which one would be louder?

I want the crowd to be amazed from the booming noise when it fires, so I was thinking, since theres no way it will be very loud from a 10 foot barrel of either size, I would drill holes along the barrel after about 5 feet. Is this a good idea? I wish i could test this but I only have 1 piece.

Does anyone have any other ideas?

[Jared Haehnel]

Use a burst disk or something that releases a bunch of energy at once. A few layers of making tape would work well for this. When it broke it would make a very loud poop or bang.
Ten feet is a very long barrel how big is your chamber?

In all likely hood you barrel could be shortened and would increase the noise factor and perhaps the performance.

Yes drilling holes would help but I would recommend shortening the barrel

[pizlo]

I can't really help you with your questions (sorry), but I know shooting candy up is good, you will probablly be able to get lots of shots of with the regged c02, so think about shooting other stuff, just shoot the hard stuff up...

[BigGrib]

10 foot barrel is overkill, dude you wanna shoot confetti a short distance not a mile. depending on your chamber size i would go with a 3 inch barrel maybe 5 feet long at most, but why dont you make the barrels interchangeable with either cam locks or threaded deals.

[pizlo]

yeah threads are cheep and let you test. all my guns have several barrels.

[BigGrib]

i found some really affordable aluminum cam locks for my blue blaster 11 bucks for a female and 4 bucks for a male

[bugsingelyn]

I forgot to say, it should be 10 feet because it is going to be the barrel of a large pistol. The pistol frame will be styrofoam, and the launcher's chamber will be inside an opening carved in to the handle (L shaped cannon). I suppose I could cut it down to...6 or 7 feet, but any shorter and it will look unproportional.

Use a burst disk or something that releases a bunch of energy at once. A few layers of making tape would work well for this. When it broke it would make a very loud poop or bang.

A burst disk would take too much time between shots, and I already have the piston valve and chamber finished. Unless you are talking about after the valve? Please confirm.

I could have gotten threaded adapters and tested earlier but I was hoping someone would tell me, generally, if a larger bore barrel is louder from personal experience.

Sorry for the confusion.

[potatoflinger]

Well, since you need to have a longer barrel, I would say use a smaller bore to compensate for the longer length. Adding a burst disc after the valve would increase the noise a little bit, but I don't think it would be worth the effort since it would take a really long time to change the burst disc.

[Jared Haehnel]

Ok I've a bit of time so I am going to run this idea quick. I would go ahead and use the 3 inch barrel. If you can make it a breech loader. Then have preloaded sabots that you stick into the barrel that fit rather snugly. The snugger the fit the better. The sabots would have to be made of a lightwieght foam of some kind so when it luanches it would strip away and if you make it you could cut it up into small pieces so when it strips away and dumps the confettie is becomes part of the confetti and poses no danger to the bystanders.

If you luanch it up into the air you would have no worries.

A smaller bore would help to increase the niose since the gas would not have expanded as much as it would have in the larger bore. thus it would contian more energy and create more of a bang. But you can make this up using a higher PSI. Heavy objects would also make a louder bang... but you can't be luanching heavy objects... If you make it a breach louder you might be able to rig somethign up to easily replace a bust dirst. every shot....

Really you've got to play around with it some.... Don't be afriad to experiment some... I don't think cutting holes in the barrel will work as well as a shorter barrel since you've got all that extra length that muffles the sound of the bang...

Anyway those are my ideas...hope in some way it helps...

[DYI]

There are two things that can simply make a pneumatic louder, but they have to work in unison:
1)larger bore (see 2)
2)less barrel volume. If you use a larger bore with the same length, it will get quieter. Larger bore with the same volume as the smaller bore will be louder, and larger bore with less volume will be even louder.

[bugsingelyn]

Thanks so much for the help. I will use the 3 inch barrel then. I made a really cool breach loader that I am very proud of. It's so satisfying to load.
I will definetly post the cannon once it is finished.

Then have preloaded sabots that you stick into the barrel that fit rather snugly. The snugger the fit the better. The sabots would have to be made of a lightwieght foam of some kind so when it luanches it would strip away and if you make it you could cut it up into small pieces so when it strips away and dumps the confettie is becomes part of the confetti and poses no danger to the bystanders.

Except I am extremely confined when it comes to saboting, because only tissue paper confetti can be left on the ground. I suppose I could get a runner to pick up the sabots from the streets, but it is just one more thing to worry about. I did some tests with another pneumatic I have (2.5 inch bore, similar valve) to see what looks good, and a square of tissue paper and a small piece of tape makes a wonderful bag to put a handful of confetti in. If I were trying to get more distance I would use a proper sabot, but

[jackssmirkingrevenge]

I forgot to say, it should be 10 feet because it is going to be the barrel of a large pistol. The pistol frame will be styrofoam, and the launcher's chamber will be inside an opening carved in to the handle (L shaped cannon). I suppose I could cut it down to...6 or 7 feet, but any shorter and it will look unproportional.

I might be stating the obvious here, but can't you just use a tiny barrel (just a foot or so, make it really loud and for confetti it will be effective enough) and just sleeve it inside a larger diameter barrel for looks?

[bugsingelyn]

I might be stating the obvious here, but can't you just use a tiny barrel (just a foot or so, make it really loud and for confetti it will be effective enough) and just sleeve it inside a larger diameter barrel for looks?

Isn't that the same as having a longer and larger diameter barrel? If I sleeve a short piece of 3 inch in a long piece of 4 inch, wouldn't it be the same or similar to a long piece of 4 inch? I actually did think about this. Correct me if I am wrong.
I will do some tests and post the results soon after.
And, of course, I will get many pictures and videos of the float when it is completed.

[BigGrib]

ok so i understand that you're trying to go for an authentic pistol look with the faux deal over it, but to solve your problem with wanting more noise instead of haveing an "L" shaped gun make it a straight gun that fits simply in the barrel of your faux pistol, this way you can have your short big bore barrel while keeping the power of your chamber. i dont know just an idea, thought it might be a good one.

[bugsingelyn]

BigGrib - I thought of that, but the piston valve and barrel is already finished. I suppose I could find some way of covering it with a faux barrel.

I did some informal testing, and discovered that (obviously), the loudest shot at 40 psi is no barrel at all. The next is a short, 1 foot 3 inch barrel. Those were obvious. The thing that surprised me the most was the 10 foot 3 inch barrel is louder than the 10 foot 4 inch barrel. It also has less of a whoomph and more of a bang. I think I will stick with the 3 inch barrel, maybe sleeved in a 4 inch barrel. I don't know the length yet though.
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I am getting really excited about this! The CO2 reg. is from a beer tap (float is for a bar) and it fills way faster than a paintball reg. I tried earlier. I calculated many times and found that i will use about 1 ounce each shot at 40 psi. Not bad, I have enough tanks for 80 shots.