Spud Gun Ignition System

[kitkitkit]

Ive recentley made a spud gun. I use a good flammable propellant, but i need an easy to make ignition system. Without using piezos or BBQ ignitors, or sparkplugs, can anybody help me by telling me how to make an alternative ignition system. Im only 13. Please help...:flame:

[Cap'n Refsmmat]

Buy a flint/steel lantern sparker from a camping store or in the camping dept. Bore a hole through the end cap of the barrel and stick it in.

[kitkitkit]

Are there any other ways?

[Cap'n Refsmmat]

uhh... a touch hole and a match? Or, take the ignition system from a model rocket. Stick the igniter through the touch hole and put the plug on. Wire it up, get 15 feet away(it will blow out the touch hole) and press the igniter.

[kitkitkit]

touch hole?

[Cap'n Refsmmat]

little bitty hole drilled into the breech (rear end) of the gun.

[kitkitkit]

have you ever tried the touch hole with the match. And if so, does it work. And wouldnt all the propellant gasses come out of the hole, and even if it didnt, wouldnt the flames from the combustion reaction come out of it?

 

Thanks for the idea.

[Cap'n Refsmmat]

Yes, they would come out of it, but that idea worked for early firearms! And if you want to do the touch hole, wear heavy gloves! You'd get burned by the flames.

The propellant gasses would go out, but if it's a tiny hole big enough for a match, not much would leave. It keeps you from having too big of a fuel/air mix.

PS: If you do the touch hole, it could be dangerous! A powerful flame would come out. You should take a dowel or something and attach the match to it, so you can stay a few feet away and behind the hole (the match doesn't need to go through the hole, it will ignite gas outside and that would lite up the rest)

[kitkitkit]

Any other good ideas, that one sounds brilliant. And by the way, dont forget to visit my homepage, tel me what you think. Thanks again.

[Lance]

You can also take apart a disposable flash camera and use the capacitor/transformers to create a nice spark. I don’t know how much skill you have in electronics but you could also find a flyback and build a simple driver for it. If you change your mind about Piezo-electric igniters check out http://www.scitoys.com/ you can buy one for $2.50 US. If you decide to use a flyback and people here do not have the experience to help you check out http://www.4hv.org/

[Guest jsdratm]

Spark plug ignition sucks for all the trouble you go to. I reccommend the lantern sparker method.

[Cap'n Refsmmat]

kitkitkit said in post # :

Any other good ideas, that one sounds brilliant. And by the way, dont forget to visit my homepage, tel me what you think. Thanks again.

I like both the pen ideas. I should try the exploding pen. I like blowing stuff up.

[YT2095]

why not use ordinary fuse? it gives you time to get to a safe distance as well

[Lance]

You can get safety fuses at http://unitednuclear.com/tubes.htm

As well as Nichrome wire to make an electric ignition system. If you don’t have a credit card you can also get nichrome in fish tank heaters. You can also use very thin wire instead.

 

Wouldnt wanna be too close.

[YT2095]

making your own fuse is also very easy, and there`s probably as many methods to make it as I`ve had beers

[Cap'n Refsmmat]

I take it that's a lot of methods!

[YT2095]

and then some

[Cap'n Refsmmat]

Kitkitkit, did you try it yet? Or are you sitting in the hospital after getting blown up lighting the fuse?

[YT2095]

correctly made spud guns are quite harmless (unless you`re at the business end of it), it`s a simple FAE.

a fuse or electric ignition would be the way I`de go (and have done as a kid), we used to launch tennis balls and rolled up socks

he/she probably isn`t on here at the moment to answer you tho.

[Cap'n Refsmmat]

I just thought... if a fuse didn't entirely fill the touch hole then gas would escape, and it would fire prematurely.

[YT2095]

FAE`s aren`t THAT easy to deflagrate through a small apature, vapor pressure precludes it, there is a critical diameter for each fuel used, and O2 rich you may reduce this Dia accordingly, for our 21% O2 in air, the bore maybe large enough to accomodate several fuses before worries of a "blow back"

[Lance]

Yes a fuse would be very easy to make but if he/she is 13 then he/she will need to find some potassium nitrate and sulfur. Both of which are no longer a household product. The Site a gave I link to up there sells both and has instructions for making the fuse. http://www.skylighter.com/ Also has the chemicals but you will need to send them an ID.

 

Unless of course you make the fuse out of crushed matches...

[YT2095]

YT2095 said in post # :

making your own fuse is also very easy, and there`s probably as many methods to make it as I`ve had beers

 

the need for ANY of those chems you mentioned are not required either.

soaking kitchen paper towels in plant food and letting them dry will work also

or sodium chlorate weed killer, and if you don`t want to buy that, then take the carbon rods out of a normal zinc carbon battery and elctrolyse some salt water, filter and soak your kitchen paper in that,,, as I said, there`s a kazillion ways to make a perfectly workable fuse

[kitkitkit]

Cool. Thanks everbody. You know you were talking about that disposable camera one, well about 6 months ago i made a taser out of one of those and i got a 300v shock making it (all by the age of 13). I love things that go bang. There is this really coll book i recomend to all of you, i got it today, its called backyard ballistics. Dont forget to check out my website.

[kitkitkit]

Btw im a he. At school ive benn made the "lab technician" and i have access to a wide variety of chemicals. Lately during break i nicked some magnesium. Sorry Mr Watson.