A different way of sparking...

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Hubb
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Wed Mar 04, 2009 11:24 am

I'm in the mood to build a new combustion. This time, I want it over / under. It's going to have all the features that's needed (propane meter, fan, etc). But I've been debating on a new spark method. I'm going to use a piezoelectric igniter for this one. I don't really need a stun gun, and figured a piezo would be just a bit more simple to construct.

Now, let me describe: I was thinking about using the Hubbrid Spark Plug for this. (The Hubbrid Spark Plug). Of course, this design would interfere with the chamber fan and exhaust, so I thought about running it through the front of the chamber. See diagram for more detail.

By doing so, this would make it so that no ignition holes would need to be in the chamber, be easily removable if needed, produce a minimal amount of heat loss in the chamber due to less parts, and center the spark.

I may even go so far as adding multiple sparks, maybe imitating the AdvancedSpuds Hybid Ignition System in a way.

Any thoughts on this? Has it been tried? Will it negatively effect the launcher?
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jackssmirkingrevenge
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Wed Mar 04, 2009 11:30 am

I made something similar here ;)
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Hubb
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Wed Mar 04, 2009 11:32 am

I was almost certain it had been done before, but what are the thoughts on putting it in the front of the chamber? I know it will work, but that was my main concern. I don't want it to interfere with anything going on inside the chamber (although, I'm fairly certain it will not).
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jackssmirkingrevenge
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Wed Mar 04, 2009 11:34 am

I'd be more concerned with the 90 degree bend to the barrel.
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Hubb
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Wed Mar 04, 2009 11:38 am

Yeah, I'm more inclined to build inline combustion, but I couldn't figure up a way of doing this type of sparking system with an inline. Plus, I want this one to be a bit larger than the last one I built so the whole space thing come in to play and all.

If I could figure a way to use this type of sparking system for an inline, without having to add more holes to the chamber, then I would do that (I think that was my way of asking for any suggestions :lol: ).
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jackssmirkingrevenge
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Wed Mar 04, 2009 1:03 pm

hubb017 wrote:(I think that was my way of asking for any suggestions :lol: )
I would make suggestions but you might not be partial to copious quantities of epoxy resin ;)
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starman
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Wed Mar 04, 2009 2:09 pm

I think it would be fine. Just make it as thin a profile as possible so as not to choke the flow to the barrel. You'll need to keep the leads fairly well and consistantly separated/insulated from each other.

I like the Advanced Spuds strip as well, but I think it's a little unnecessarily bulky. I actually almost built that myself, even special ordered some 1/4" sched 80 pvc pipe to do the job.
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Hubb
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Wed Mar 04, 2009 2:19 pm

Well, if I did construct the HIS, it would surely be different and more fitting to what I'm trying to do.

As far as the leads go, a better explanation is in the link above. The coat hangers I will use will work to put it where I want it.

I've also thought of a way to put this in the rear of the launcher, which would then lead back to an inline (although I still may go over/under for size). I'll see about a diagram...
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Hubb
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Wed Mar 04, 2009 2:42 pm

Sorry for the double post, but I couldn't edit the picture into my last one.

Anyway, I was thinking I could lay the fan against the wall then run the spark gap over the fan. This got me thinking (and doing more research) and I thought, "why not add a second fan for increased turbulence?"

Well, I figured I could add two fans, having the gap go in between them, but then angle them. The angle would help with venting and create the turbulence in a forward motion.

As far as the spark gap going to the rear of the chamber, I could just place it a bit off center, which would run next to the exhaust valve.

I could always just put in a spark strip if necessary, though...
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starman
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Wed Mar 04, 2009 2:50 pm

You could always place the fans in different locations in the chamber, one at the rear and one maybe in the middle both blowing toward the breach. My gut thinks your above config would be a little redundant....I'm sure it would work fine though.

Also, getting those fans mounted in the chamber at an angle like that will be a good bit more challenging than usual.
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Hubb
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Wed Mar 04, 2009 3:00 pm

Nah, I got some ideas...

As far as mounting one in the end and one in the center, well, first off, the one in the end would interfere with the spark gap, while the one in the center will be challenged by the flame front pushed by the one in the rear (make sense?).
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psycix
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Fri Mar 06, 2009 4:27 pm

My concern in the spark gap system in your first post is that it obstructs the air a little.
Also, I wouldnt be very surprised if you happen to find your electrodes in your target.
Just as you dont want your fan to interfere with the flow, you dont want your electrodes to be in the way.


@ your second design with the two fans against the wall:
This might be geometrically impossible.
Realize that in the real world, your chamber is cylindrical. You cant put a fan straight against the wall like that.
The angle of being able to mount your fan depends on chamber diameter and the size of your fan.
The fans need to be somewhat small compared to the chamber diameter if you want to place em at the angle as in the picture.

You could also have your fan almost the back, just in front of the electrodes.
I do, however, think that having your gap in the center is a must for optimal performance.
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Hubb
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Fri Mar 06, 2009 4:30 pm

I've been thinking about this whole thing, and I have come to the conclusion that a spark strip and one fan standing upright is the best, and easiest method.

Thanks anyway, though.
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