New here and NEW to potato guns

[TaterTot]

I've been looking for a release........ and i think i've found it.

I am a gun nut, but there is something about hurling large projectiles long distances with stuff I can buy in Home Depot that puts a smile on my face.

I want to construct my first launcher. I have a general idea, but plan to use this place to learn and do research.

The simplest method I see is a 4'' rear tapered to 2 inches. some spray (not sure what it is) is sprayed in the back, closed up and then ignited by a grill spark.

What is the propellant?

[Mr.Sandman]

I've been looking for a release........ and i think i've found it.

I am a gun nut, but there is something about hurling large projectiles long distances with stuff I can buy in Home Depot that puts a smile on my face.

I want to construct my first launcher. I have a general idea, but plan to use this place to learn and do research.

The simplest method I see is a 4'' rear tapered to 2 inches. some spray (not sure what it is) is sprayed in the back, closed up and then ignited by a grill spark.

What is the propellant?

Well generally I try not to spoonfeed, but hairspray and body spray are some blatantly obvious choices. If you have ever seen a video of one they usually say what they are spraying into the cannon. Another choice is propane. But I think you could have found your answer by simply looking in the combustion cannon showcase.

[iknowmy3tables]

almost any flammable spray works, when it's mixed with the right amount of air it will explode. just like gasoline in an internal combustion engine pour it in a cup and light it and then it burns slowly, but in in engine it's mixed with air it burns even quicker and it explodes

any flammable liquid atomized (you can use a basic spray bottle) or a flammable gas like propane or methane

[jhalek90]

Well, if you want real power, i would recommend going pneumatic, or better yet build a hybrid.

But, the hybrid requires much more experience than a combustion, or a penumatic.

If i were you, i would start by building a combustion, and a pneumatic, and see which type you prefer.

For a pneumatic (my specialty) i would recommend a 1'' sprikler valve cannon. Take a look in the pneumatic cannon showcase section for a few good ideas.

WELCOME TO SPUDFILES!!!!!!!

[TaterTot]

well, this will be my first one, but i dont plan on building a little one, i like to go all out. If i went with a combustion using one of those coleman fuel tanks, what sort of setup would i need?

I have surfed a lot here and much of the combustion section is a bit advanced for me as of now. Basically, i do not know what i am looking at/for

[rcman50166]

Lets not go overboard here. Starting with a combustion sounds like a good idea. Try not to use bell reducers or DWV PVC pipe if you can. They like to explode. Spudgunning is an addictive hobby, be forewarned.

Welcome to Spudfiles.

[TaterTot]

Ok, i am trying to figure out the dynamics of one here.

what keeps the propellant from exiting the chamber prior to being ignited?

the potato? if i used propane, would i need a stop valve behind the potato or is the potato enough to keep pressure in the chamber?

[Insomniac]

The chamber isn't pressurized unless you're building a pneumatic or a hybrid (not reccomended for a newb). The fact that the chamber is at atmospheric pressure means that there is very little force wanting to make the gas leak out, so the projectile is more than enough to seal it up.

I reccommend you build what's usually caused an 'advanced combustion', with a chamber fan and a metered propane setup (use the search and do some reading)

[TaterTot]

The chamber isn't pressurized unless you're building a pneumatic or a hybrid (not reccomended for a newb). The fact that the chamber is at atmospheric pressure means that there is very little force wanting to make the gas leak out, so the projectile is more than enough to seal it up.

I reccommend you build what's usually caused an 'advanced combustion', with a chamber fan and a metered propane setup (use the search and do some reading)

gotcha. but wouldnt the propane be under pressure?

[King_TaTer]

Let's forget about the propane for now shall we? I recommend using a respectable fuel such as starting fluid for your first potato gun. The most important part of spudding, in my opinion, is safety and it helps a lot to know whats safe and what isn't. Check out this link in order to learn how to identify pressure rated parts and fittings. For a simple combustion that uses spray fuels pressure rated parts aren't required but still highly recommended. Also you might want to check this out as well to learn how to properly solvent weld so your joints are secure and don't explode.

By doing a quick search you can figure out how to make a reliable spray n' pray combustion cannon. You can either use a 4" chamber to a 2" barrel or a 3" chamber to 1.5" barrel. There are a lot of possibilities but starting small is recommended. Well good luck with everything and most other questions can be answered by searching.

[starman]

I second King Taters recommendation. Get your kicks first with a basic PVC spray and pray. Learn the basics and its limitations and you'll be in better position to move forward with something more advanced.

Don't know if you've seen this or not....

http://www.break.com/index/girl-in-unde ... o-gun.html

We drag it back out every now and then....jus' for fun of course....

I do recommend you move to propane soon after your first experiences with spray can products. You'll find they leave unwanted residue and get harder to fire after some usage.

[jackssmirkingrevenge]

We drag it back out every now and then...

Oh yes *sigh*

[Moonbogg]

You are getting a lot of differing opinions here, and thats a good thing. My advice is to do a lot of research first, think a lot about making it, and then make the best cannon you are personally comfortable making. I started with an advanced combustion with metered propane, chamber fan and 3 spark gaps. I researched a lot and still screwed it up the first build. I got it right on the second build. It wasn't expensive and didn't take long. I used cellular core ABS and it worked, and still works great. I mean, like really packs a ridiculous punch.
If you are prepared to spend money on entry level cannon and know you will upgrade soon, why not do a little more research and go for a better version first?

[SpudBlaster15]

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[clemsonguy1125]

http://www.instructables.com/id/The-Ori ... to-Cannon/
http://www.instructables.com/id/How_to_ ... _LAUNCHER/
Heres a couple more how- to's, notice some of these didnt use pressure rated parts but you should its probably a good idea to, also it might be good to start small so you can trouble shoot some problems