First Cannon is for a Family Build Off

[BlackSheepTxRx]

In about 2 months I will be heading to the coast for our annual family fishing trip, every year is a blast with the guys eating, drinking, fishing etc. just doing what guys do. The past few years we have been using Potato Cannons to launch our bait into the surf which combines two of the manliest things you can do, fish and shoot stuff at the same time. Well this years fishing trip as evolved to include a spud gun shoot off, a $20 dollar buy in with the winner take all. I want to take all.

I have a feeling that my competition is going to be using mainly combustion cannon's consisting of hair spray or some other highly flammable substance; and while playing with fire to launch a spud a few hundred feet is satisfying I want to be able to launch further than anyone else. After doing a bit of research with my limited build experience (which is none) my best bet is to use a pneumatic cannon.

With my non-existing experience I want to keep the design simple. I am thinking an over-under set up with the pressure tank being 3 inch pressure rated pvc at about 4 feet long with a barrel of 1 1/2 inch ppvc at about 6 feet. The trigger will be a modified sprinkler valve.

Last but not least I am thinking about making the barrel a vacuum barrel for greater acceleration of the projectile.

I am looking for advice or obvious improvements that would take this build to the next level and assure me the victory at the end of the competition.

Thank you

[Juggernaut12121]

I realize this is a bit late but if you wanted too you could download two programs called HGDT and GGDT. With the former you could roughly estimate your competitions' range and with the latter (seeing as how you want to go pneumatic) you could figure out what dimensions and pressure would put you over them.

That being said, seeing as how this year's competition is over, maybe you want to try and really blow away the competition next year with a hybrid? Making one with a burst disk is pretty easy, but you'll have to reinforce your potato

As far as your proposed setup, how did it go? I would only suggest that you use a piston valve rather than a sprinkler.