I’m gonna be making one of these soon, the combuston type. I’ve been looking at a few sites and think I’ve got a pretty good idea on how to do it now. I’m prolly gonna be using a 12" long chamber with a diameter of 4". According to the calulations off a site the barrel should be 7.1 feet long and have a width of 1 and a half inches.
I’d like to know, has anyone else made one? Pics/Vids?
Any advice for me?
My nephew built one a while ago. It was lots of fun, but it was pneumatic and the triggering mechanism didn’t work well. As long as you keep all your fingers attached, a combustion potato gun should work better than the pneumatic type.
Actually, where your fingers end up won’t affect the performance of your potato gun. It will just determine how many times you can fire it. 
Haven’t made one but I’ve used one of the combustion ones…lots of fun!
Andrew
rule #1: resist the temptation to look into the end to see if the potato is stuck.
rule #2: if you want to shoot it like a rocket launcher with it over your shoulder make sure u brace yourself first
never ever underestimate how far your potato will go
always use hairspray for combustion (imo).
make sure your pcp pipe is put together well before testing it
…many of my friends have made them and i’ve watched them all do it…but i haven’t made any of my own cuz i have no place to shoot it.
o yea and if u get caught with it in your car you could get in a wee bit of trouble
let us know how it goes
i think these are the webpages my friends have used:
http://www.geocities.com/spudgunner_6/
http://www.mshamash.com/spud/spudgun1.html
-grant
Ummm…how dangerous are these things?
they can put a hole right through a person and kill them if your wondering. my freind made one, its so much fun firing them at night because like a 2 foot blue flame comes out of the barrel 
so if you are going to make one plese be careful.
Make sure you try filling it up with water, then launching it. It’s like a firework. I wanted to try it with Kool-Aid, but at the moment we were trying the water, there was a drought or something here. So water usage was limited.
Re: Spud Guns (Potato Cannons)
what sites? I’ll make one with my friend we’l have fun.
They are the best one’s I’ve found so far.
I just read last night that anything over 4 feet of barrel is stupid… so now I’m just gonna look for the optimum chamber size and use a 4 foot long barrel. It turns out I did a 1:1 ratio on the other barrel thing… but still just read below… this should be right.
Volume of chamber should be 1.5 times the volume of the barrel. So here I go, I’m gonna work out the size I want to have. 1.5" barrel, 3" chamber… let’s find it out! I’m personally just gonna find out my chamber length. Chamber Radius = CR. Chamber Length = CL. Barrel Radius = BR. Barrel Length = BL. (All measurement in inches)
Pi * CR^2 * CL = 1.5 * Pi * BR^2 * BL
Pi * 1.5^2 * CL = 1.5 * Pi * 0.75^2 * 48
Now I can’t be bothered using any algebraic methods to find this, so I’ll simply use the Solver function on my graphics calculator.
The optimum length for a chamber of 3" diam if you have a barrel 1.5" diam and 4 feet long is:
18 inches.
Foot and a half.
Time to make me one!
Guns? Guns?
Have a look at this ready to use gun you probably have ready at home.
Be carefull. And realize that the thing may explode once the flame goes inside the reservoir.
I’ve made some of these. Lots of fun if you’re careful.
Hairspray seems to be best fuel I’ve used.
petroleum distallates will weaken PVC and eventually destroy it.
7 seconds is what I use.
For ignition, grill igniters are about the most expensive and least effective I’ve found, yet still seem to be the standard. Best i’ve ever used is an Aim-n-flame epoxied into the end of the gun—pretty much 100% ignition rate.
Also used a spark plug epoxied in the end connected to the element taken out of a piezoelectric lighter.
There was a guy about a year or two ago who blew his face off trying to shoot live frogs out of one–once it didn’t fire, so he looked down the barrel while his friend held the cannon–by the trigger. He lost both eyes and his nose, but survived–if it had been a potato, he’d be dead.
Don’t be stupid, don’t be cruel to animals, and have fun!
for some reason, I can’t access my files on my ISP…but, I have a cool video of my doing the same with my mouth.
I’ve built one, they definitely are fun. The one I built has a barrel about 4’ long x 2" wide; any longer is just hard to transport and store. A 1 1/2" barrel would be easier to load spuds. The combustion chamber on mine is about 8" long and 6" wide. With this setup and hairspray I can shoot a potato probably a little over a quarter mile. Hairspray and air fresheners are both excellent propellants.
And use PVC not ABS pipe.
Nice… I think I know what I’m gonna do with ignition. Since I’ve got a large chamber:barrel ratio, and a thin barrel, I’m thinking that with my luck and all it could explode… So I’ve decided to set it up mortar style, with electronic ignition. Call me a pussy, but I’ve found quite a few bad storys on the net, no only of idiots looking down the barrel, but of some chambers just exploding. I’d rather not be holding the chamber when it goes off.
I’m gonna use the: convert your disposeable camera that has a flash into a stun gun ignition method. Find out how to turn the flash of a disposeable camera into a stun gun, and merely incorporate it into the chamber. Gonna have me some button ignition. It’ll look funny too. I’ll prolly also experiment with shorter/longer barrels aswell considering the fact that I won’t have to hold the Spud Gun!
Step away from the thread, this is a threadjack!
Similar, but not quite…
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=10554&item=3695608433&rd=1
Phil
If you build the chamber properly and out of the right materials (PVC not ABS) and the right glue, you shouldn’t have an issue with it exploding on you. For added strength, you can put 3 or 4 large pipe clamps around the combustion chamber.
That minigun is crazy. I’d like to give paintball a go, jsut a few questions…
Do people make their own paintball guns?
How much would a paintball (ammo) cost?
What sort of store could I find them at?
Anyway to make your own paintballs?
People generally do not make their own paintball guns, however they do combine various components (barrel, hopper, feeder, trigger, etc.) to design their own custom guns.
Bulk paintballs can be as cheap as 2 cents each. typically you can count on paying about 10 bucks for 300 balls, just for a ballpark figure. Of course, this is canadian $$.
I don’t know of a way to make your own paintballs, but I’m sure it can be done. In the end you’d probably be better off just buying them though.