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In this episode of weekend projects, you will learn how to bring a rain of apples and pumpkins upon the earth.
For the Johnny, an apple shooter, I used a bbq igniter to ignite the fuel. After doing some research, I've found that my muzzles are too short. The volume of the muzzles should be 1.5x the volume of the ignition chamber. The next vegetable projectile that I make will have a longer muzzle. Of course then they won't fit into the spud gun rack in the back window of my car! I used 2' of 4" diameter abs for the ignition chamber and 2' of 3" abs for the muzzle. If I were to do it again, i would use 4' for the muzzle.
For the pumkin canon, aka the "Pumpk-zooka," I used a five foot piece of 4" abs. In truth, I could have used the entire 10' section and gotten A LOT more power out of it, but I'm limited by what I can fit in my car. True pumpk-zooka fiends will buy a trailer or set up a hydrolic rig in the bed of their pick-up truck! Because I was a scared of the pumpk-zooka's raw power, I set up a remote switch. The stun-gun's switch popped right out and I soldered a long set of wires to it so that I could hide behind a log just in case the plastic ruptured. Today is the Pumkin Chunkin, a worldwide pumpkin tossing championship for vegetable projectile enthusiasts. Here's a previous blog post about it.
Videos!
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- Here's an mp4 for your psp.
- Here's a giant hd size quicktime mov for those with quick download speeds.
- Here's a 3gp and 3g2 for people who like to watch on their phone!
And you can browse all the Make: videos on blip.tv and youtube at your leisure!
Note: not for use in California, and probably several other states. But damn if it isn't fun anyway.
There's a trick to pumpkins, that darned hollow center makes them prone to breakup if the pressure behind them is too forceful, my uncle and I built a chunker cannon a few years back for his local pumpkin festival down in Georgia.
The thing had a overly powerful compressor and tank, and a very fast valve, not to mention a smaller valve opening than I would have liked, which led to literally blowing a hole through the pumpkins (and subsequently the pumpkin out of the barrel, but after the innards). So we build basically a diffuser, ok so we cheated and used ventilated heat diffusers like you'd get at walmart, plus a little extra plumbing, now the pressure builds behind the diffusers evenly.
Although we've blown out more than one of those diffusers in the past, and made adjustments to them since like boring the holes larger, the concept has worked very well, and we make pie of many fewer pumpkins now.
Our next project together is to build a Jet chunker, use jet exhaust for the required pressure to launch the pumpkin, and probably a larger array of diffusers since we now have to deal with heat. But this one we'll start smaller scale, much much smaller, tho we might end up with flaming tennis balls flying around.
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Bre! It was painful to watch you shove that apple down the barrel of the "johnny" next time use a deck screw to make a stopper in the barrel to prevent your projectile from falling into the boom chamber. Another thing that will help you, Make a lever for the cap on the gun (much easier to remove the cap with a lever) I'll post an instructable tommorow with these helpful hints.
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can every body buy the stun gun?
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I think you might have to be 18 in WA state, but I just went into a gun store... you can get them on the internet too!
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