SpudFiles

Hi Again Spudders!

Here is the newest addition to the family! I call it "The Jackal", a silly reference to the Bruce Willis movie.

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And a walk-through of the cannon:
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The Specs:
- 36" x 1.5" SCH40 PVC Rifled Barrel
- Bolt action floating barrel
- 100 cubic inch 3" ABS combustion chamber
- Triple gap ignition spark array
- Integrated 12v rechargeable battery pack (in shoulder stock)
- 10 Watt chamber fan (that's powerful)
- AA Battery BBQ igniter
- 20kV Rated Ignition wire
- Rain-proof cover plates for all wiring
- On-board metered propane injection system
- Re-purposed on-board fog horn propane tank
- 1" ball valve vent
- 4" ABS housing

The barrel I got from Jeremy at Spudtech. Thank you!!! I think I put this finely crafted barrel to good use.
I made ammo out of flour using a handmade plunger mold and dipped the bullets in wax to seal and catch the rifling. The second recipe worked very well!

Holy shit that's cool! Sure does have a nice sharp report!
Two questions; one you said you were using ABS, does some ABS come pressure rated? I wouldn't fancy having that rupture with your cheek pressed against it! The second question is how did you seal the bolt action mechanism? I have a general guess that it involves the actual chamber and the barrel attached to a sort of fake housing chamber, sealed with O-Rings?

Excellent build and video (I might have watched a couple of car faces as well. )

A few questions:

1.) What kind of "10 watt chamber fan" do you have in the chamber? Is it brushless? Not that it really matters if you handle the cannon safely, I'm just curious.

2.) How does the barrel seal against the chamber?

3.) Any details on the electronics? Or is it just a simple switch and battery to the fan.

4.) Why flour?

Good job again.

WizardNoodle wrote:Holy crap that's cool! Sure does have a nice sharp report!
Two questions; one you said you were using ABS, does some ABS come pressure rated? I wouldn't fancy having that rupture with your cheek pressed against it! The second question is how did you seal the bolt action mechanism? I have a general guess that it involves the actual chamber and the barrel attached to a sort of fake housing chamber, sealed with O-Rings?

I didn't see this post, but if the ABS is solid-core it's perfect for combustion launchers. That said, at least in America-land, solid-core ABS is hard to come by.

Epic! Love all the details... nice aesthetically, great ammo... fun!

Thanks all! Lemme do my best to answer your questions.

1) The ABS is cell core DWV pipe not pressure rated. I still use it for a few reasons. One is that it visibly deforms before failure. I have never had it fail on me, besides a 3" male adapter break because of a drop. Another reason is this video:

There are two layers of pipe protecting my head from the combustion, so I've got that going for me too.

2) The barrel is sealed using the pipe tee and an oring. The barrel slides fully into the ABS bushing so there is a friction fit. Vaseline is used to get it in all the way. Then an oring goes around the barrel and sits against the edge of the tee that holds the bolt. The oring is pressed on the other side against the ABS bushing and the bolt action has a slide wedge that smashes it together. The oring actually gets permanently flattened with the pressure. No leaks!

3) This was the fan I used: http://www.ebay.com/itm/Sunon-60mm-x-38 ... SwVupTmSf5
It's a beast!!! and brushless too.

4) No special circuitry on the electronics outside the 12v battery box. I just turn the fan on and off at the box inside the shoulder stock

5) I used flour because I wanted to make consistent ammo that was still okay for the environment. Potatoes are great, but they are not the same each time. Flour is cheap too and can be binded with just water. It's great for survival biscuits too! I could have used concrete, but it might have scratched up the nice PVC barrel.

I'm thinking of making a disassembly video so you all can see how it was constructed better because I'm not sure if I explained the barrel sealing well.

auxiliary wrote:Another reason is this video:

That accent was literally shocking. How far away can you physically be from any chosen border of the United States? This guy was born and went through all 12 years of school in that exact spot.

Nice details on the sealing, but it was a little confusing. I've also played around with similar fans to that one and they are very powerful (and loud).

Good job again.

Yeah if you plan to watch any of his videos, were are quite great, just put the speed at 1.5x and then it sounds better and less soul draining.

Very rare that one sees a whole "weapons system" put together, great stuff! I especially like the fog horn propane dispenser. And the fact that you've stuck to the foodstuffs theme by going as far using an egg as a projectile mold really puts the icing on the cake, bravo!

Thanks a lot! It's nice to have everything right there in one package. I posted a walk-though video above and I explain the barrel sealing as the first topic. Then I go on to explain everything else in case you're patient.

I saw the video in my subscription feed this morning, it cleared things up nicely!

This might be a few years late but I just had a question. Did you screw the chamber to the outer layer of pipe? Or is it just a friction fit? I am making a cannon quite similar to your design and it looks like your walk through video no longer works. I hope you see this, and thanks for all the info you have already put out!

Man, of course the walk-through video of this awesome af creation had to be unavailable, was gonna take some *heavy* inspiration on it for my second potato cannon, still a sick as hell build!

great work