Potato gun igniter...

[einhander619]

I too have compressed air potato gun actuated by a sprinkler valve, and let me tell you, the performance is unreal! It will put a 2" chunk through plywood or over 500 yards away, your choice. Unless you're going to use propane, I wouldn't bother with a combustion gun. Here's a link that I think you might find useful and very entertaining.spudtech.com

[Tyril]

My friend and I made one a couple of summers ago, and we found that by far the best method of ignition was the grill igniter. The secret is in the mounting, however. We used two un-finished steel screws each pointing inward at about 30 degrees. This allowed us to easily screw one in farther if on one day the spark was not gapping, since screwing it in lessened the amount of space between the two pieces of metal.

Man, those things are fun. I've gotta built a nice ABS one this summer.... or even steel powered by ether =) I've heard stories of those things firing over a mile when burning ether!

have fun, and don't kill yourself,

-mike

[personman]

Well, I just came back from home depot with all the parts I need except 2..

The guy there said he had built potato launchers before and he seemed to know what he was doing, and he said I would be better off to use like a camping igniter that you twist and flint rubbs against a wheel and makes sparks. (im pretty sure thats what killmore was describing)
The guy saw the instructions for the cannon and said the chamber was too small so he lopped off a big piece of 4" pvc and a piece of 2" pvc and gave me the parts for the cap..
They were out of 4 to 2 reducers though, and he told me not to go with a bushing because it wasnt nearly as stable. So its going to be a pretty simple cannon, which is good I guess because not many things can go wrong.

[KILLMORE]

Personman,

A roll flint is a a brass rod with a flint on the end that sparks when spun. You can pick them up at Wal mart or prabably home depot. Just ask for a lantern flint and you should have no problem. Easy to use and less complicated than a compressed air design, you cant go wrong.

[KILLMORE]

didnt see your latest post

[personman]

Well it took some dremel work to make the igniter work like how I wanted to, and I snapped off the knob that makes one of the flint things spring loaded for pressure (lucakkly it was screwed in all the way when I snaped it) and I had to figure out some things about how to do it, but I made it, and it looks nice and clean ( from the outside atleast) its drying right now and then im leaving for oklahoma tommorow morning so ill test it when I get to oklahoma.. that will be pimp..
Here is a pic..

[personman]

Inside of the cap

[personman]

This thing gives off alot of sparks! If I cant get it to light with this I might as well give up

Ouside of the cap, just twist that little knob and BAM

[mirthvader]

Be careful with that thing. Reason I went with air is that I can control the pressure. I know it's never going higher than 100 psi. With gas, you never know.

[personman]

Well, my grandparents have 40 or so acres of farmland in oklahoma, andi m about to go there so I should have plenty of room to fire the cannon.. I can even try to pluck off chickens from a distance

Nahh they dont have any chickens..

[BTAutoMag]

wheres butterfingers when you need him

[Sinnet]

my friends and i have a 3 inch gun, its about 15 feet long... we use spray deodorant and a kitchen torch to fire it, although we have a stun gun coming from ebay...

started firing big potatoes... then carved a wooden shell, and now we've got a mold made for concrete ones, havent tried them yet though

[mirthvader]

When I said be careful, I didn't mean with aiming the gun. The problem with hair spray or that type of firing system is you have no control of pressure in the barrel. You are using pipe made to withstand a certain pressure. Put a little too much propellant or have a problem with a plugged barrel and the pressure can rise quickly and blow your gun up causing death and dismemberment. Oh wait, I'm starting to sound like a parent. Never mind.

[OKJEFF4]

I recommend the CA ones also. Mine has a guage, and I screw in a 12oz tank. I've got a reg to hook up with it too. It has interchangeable barrels too, so I can shoot ping-pong balls (through a mason jar) or I can shoot a potato or pop can full of cement. Where in OK are you going?

[_Spork_1]

buy a grill button igniter, it sets off a spark when you click the button, just drill a hole into the chamber for it and it works like a charm

also, get a bigger chamber,you'll get no distance on that thing