Mounting the Ignition System

[sooch90]

Hey, I'm building my first Potato Cannon. I cut the PVC pipes to the correct lengths and and cemented some of the pieces together. However, I'm stuck on mounting the Ignition System. I've seen a couple of configurations, but I'm not sure which to use.

I would prefer having the actual "red button part" (sorry I don't know the name of it) of the BBQ igniter half way in the combustion chamber with only the red button sticking out of it. However, the "red button part" of the BBQ igniter is made of plastic. It also doesn't have a nut or some sort of screwing mechanism to secure it in place. Instead it has 2 plastic clips



See the 2 clips?

Do you guys think that would be enough to prevent the button from blasting out of the Combustion Chamber?



The other configuration I was think of was having the "spark box" (again sorry I don't know the name) inside of the combustion chamber. I don't have a way to secure it INSIDE of the combustion chamber so it would kind of hang there. Then drill holes in the combustion chamber so the wires could come out of the Combustion Chamber. The wires would then be connected to the "red button part" and the "red button part" would be taped down to the OUTSIDE of the combustion chamber via duck tape.



That's the "red button part" with the wires connected to the "spark box".


So what do you guys think I should do? Thanks in advanced for any help!

[sgort87]

I really really really really suggest making an ignition handle like on my <a href="http://www.spudfiles.com/forums/viewtop ... treamlined Simple Combustion</a>. It is truly amazing and costs maybe a dollar.

You can also add your own angles and such to raise the hadle away or angle it up at 45 degrees or something.

[sooch90]

All right, i'll think about it, but I'd prefer just putting the igniter on the gun. But my questions still stands, would the explosion inside of the combustion chamber damage the plastic igniter?

[MisterSteve124]

You can't mount the igniter on the gun. It would fly out at very high speeds. You don't even have to mount it you can just have it dangling and just press the button. You don't need that metal box it is used specifically for grills. Just cut the wire and strip off the plastic on the outside.

[SpudBlaster15]

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[sooch90]

You can't mount the igniter on the gun. It would fly out at very high speeds. You don't even have to mount it you can just have it dangling and just press the button. You don't need that metal box it is used specifically for grills. Just cut the wire and strip off the plastic on the outside.

all right yeah. I did see a couple of videos where they mounted the red button igniter actually on the combustion chamber.

Okay here is my idea for the ignition system.



I think the picture might be a little blurry, but you guys should be able to see it. The wires go into the combustion chamber and I'll strip down the wires from there after they pass through the drilled holes.

However, I'm a little concerned with the drilled holes that the wires go through. The wires don't perfectly fit in the holes, so there is some space between the wire and the drilled holes. How would I properly get rid of the spaces and insulate the holes?

[SpudBlaster15]

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[Flying_Salt]

You should be fine with it dangling there, just seal it off with some caulk and let the caulk dry completely. If you move it around before it dries, you'll get some hot air on yor arm. (like I did).

[sooch90]

Ah caulk, good idea. thanks!

Attach the wires to screws which will thread into the chamber, forming a seal and a spark gap that will be unaffected by combustion pressure, unlike one that is formed using wires.

Currently I still have that "spark box" still in the combustion chamber. Couldn't I just leave that in there? Or would the explosion in the chamber damage the metal "spark box"?

And if I do use your idea, what do you by "...screws which will thread into the chamber"? Should I attach the wires to the tip of the screws, and drill the whole thing in? or should I attach the wires to the heads of the screws on the outside of the chamber?

[Flying_Salt]

This is what the screw setup will look like.

The wires are attached to the tops of the screws, which are screwed in a short distance apart. A spark should jump across.

[sooch90]

k so the wire is attached to the top of the screw.

But what if I just wanna leave this box in there?

http://img168.imageshack.us/img168/7853/img1614dy1.jpg[/url]

[SpudBlaster15]

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[sooch90]

should I attach the wires to the heads of the screws on the outside of the chamber?

Yeah. How did you mount that box in the chamber? Do you have a picture?

sure



It spark box is sort of just dangling inside of the combustion chamber. I guess I could duck tape it down or something...


So do you guys think that would just be okay leaving the spark box in there?

[SpudBlaster15]

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[MrCrowley]

put the bbq igniter in 20mm pvc pipe and get a pipe clamp and screw the pipe to the chamber using the clamp,try and get screws with brass rods on the end to screw it to the chmaber and hook the wires up to the screws,thats what i did so if you need a pic...