Step 3: Install the ignitor

You probably saw in the last step a silver BBQ lighter attached to the side of the pipe, I tried using this, but it wasnt working, so I bought an $8 ignitor.

Drill a hole in the 3" pipe for the metal lead from the ignitor to fit, mount the ignitor using screws provided, you can slop some glue around the hole to make sure there wont be a gap where the flames will shoot out and burn your arm......

In order to create the arc (spark) to ignite the gas, there needs to be a metal contact between the lead from the ignitor and the metal chasis of the ignitor.

If you mounted the ignitor with bolts into the pipe, bend the metal lead to be within 1/4" of the bolt to make a spark,
I however put another screw in from the other side, but had to run a piece of wire from it to the metal chasis.
Both methods will work.
<p>I've made one, except I did go with steel pipes, silicone, rivets, and duct tape, and I'm using starter fluid as a propellant. Packs a hell of a punch.</p>
<p>Extra large chamber, added a handle for the igniter. Looks like it'll work great.</p>
<p>Quick question, what's the best way to make a pressure valve so that if I accidentally use too much combustables it won't explode on me.</p>
Also what will any type if BBQ igniter work
awesome must try with my kid
Firing your kids out of it
<p>Can you cut the 1.5&quot; pipe to 3 feet ,instead of 5?</p>
<p>Does it aim ? Can you consistently fire into a target range ?</p>
<p>where should i get the bbq igniter from</p>
<p>It really doesn't matter as long as it is the style with the long barrel and a trigger</p>
<p>There are these places called &quot;stores&quot;. You have to go outside though to get to them.</p>
pvc works fine as well
Try using propane lmao but watch yourself be careful dosent take much
<p>The sizes I see on this instructable are reasonable. Bear in mind that a potato is probably self-lubing, that is, they have a bit of juice to help them slide out of the barrel nicely. I would be extremely wary of shooting things that have no lube, like can goods, baseballs, etc. Why? Because if you get one of these 'stuck' (if you get a SQUIB) The pressures from some propellants can rise wayyy too much while the thing is trying to shove your item downrange. While the burst pressure on plastic might not be very high, it's high enough to create shards that are sharp if the thing blows up.</p><p>Geez. I sound like your parent. ggg.</p>
I agree. A buddy and i had a PVC launcher that launched soup cans a hundred yards or so and it exploded cause of lack of lubricant. The seal was two tight
<p>Can i use a fevicol instead of ABS?</p>
<p><strong>will this shoot a tennis ball?</strong> </p>
<p>I would like to make one of these, except mine will launch marshmallows, instead of potatos. do you know if this is possible by just getting a 5 feet of 1&quot; ABS (DWV) pipe instead of a 5 feet of 1.5&quot; ABS (DWV) pipe?</p>
<p>*and a A 3&quot; to 1&quot; reducer instead of a A 3&quot; to 1.5&quot; reducer</p>
<p>what work better than an ignitor is a coleman lanturn sparker with flint</p>
some one tell me what measurements this was taken in ?
<p>inches I think</p>
this is all imperial aka inches and such. the quote mark is the symbol for inch ( ' = foot, &quot; = inch)
I'm not to sure about the igniter part, could someone clarify
<p>my stepdad made one. he to a thick wooden dowel and drilled a whole about where your pointing finger goes. he drill all the way through and put in a barbeque grill ignitor. He stapled the wires up the back of the handle and inserted them into the firing chamber. Then use glue or epoxy to seal the hole. oh, and make sure they are close enough to arc. hope this helps</p>
<p>what can you shoot out of it?</p>
<p>it's called a potato cannon...it shoots potatoes</p>
<p>the simplicity of that burn was lovely</p>
<p>Great instructable ... my buddy and I will be making one each over the Memorial day weekend ... I may even try to find some schedule 80 transparent PVC ... anyone tried that?</p>
<p>I saw on a show that they used duck tape and it worked. Should I do that to save time or stick with the glue stuff?</p>
<p>Well the cement will last longer and also the duck tape may get blown off during the process soo.... yeah take a guess</p>
Pretty cool! I've been getting into <a href="http://howtomakefireworks.org" rel="nofollow">building fireworks</a> myself. Wrote some articles about it. Do you like fireworks or cannons better ?
Use starter fluid. Unlike hairspray, which is sticky, starter fluid burns clean. The hairspray will gum up the threads on the end cap. Make sure you seal all the screw holes with jb weld.
Hacksaws are used for metal pipes but work just as well on ABS
Super easy to make, loads of fun, quick construction. Great Instructable. I modified your instructions slightly. Instead of a grill spark igniter, I used a gas lamp spark spin wheel. A lot more low tech, but works like a charm. The advantage to your igniter, looks awesome when you shoot it! The advantage to mine, low cost.
Sorry, but a potatoe is a Tuber not a legume. Beans and the like are legumes. Thanks,
If i do this with a blow torch lighter do you still think it will work?
yeh, probaly melt the pipe though
Does any sort of aerosol work or just hairspray?
yeh use any flammable liqiud&lt; e.g. petrol,haha, deodrant
my end cap blows off, what can i do?
this is great for making a m18 recoilles rifle replica that even shoots! :D potatoes!
bcrylonitrile butadiene styrene. it is sold in hardware stores, and looks like black pvc
Hey, great instructable. I can't figure out why mine isn't igniting, though. I can see a spark, too.
Spark gap is too big. Decrease the distance between the two.
<a href="http://www.instructables.com/answers/Why-the-isnt-my-potato-cannon-igniting/">http://www.instructables.com/answers/Why-the-isnt-my-potato-cannon-igniting/</a>
Sorry, but potatoes aren't legumes. Great instructable though.
it didnt shoot a baseball but it worked axactly as advertized thanks

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Bio: I liked designing and building things long before I became an engineer, now I get paid to do it!
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