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My Hybrid!

Built a hybrid cannon? Then post it here! This section is for completed, finished cannons that you have built. Please include pictures and information.
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Unread postAuthor: wyz2285 » Sat Mar 31, 2012 1:41 pm

Thanks DYI, My friend and I did a calculation, one layer of aluminium foil does hold around 1 bar, but two layer will hold more than 2 bar, not very linear, but kind close within the range of 1-5 layers.
I used a 3/4 male and a 3/4 female to 1/2 male adaptor to hold the disc, so I considered it as a 1/2 area for the pressure to exert.
My ignition source is a tazer, witch gives a 2-3cm spark in atmospheric pressure, 1mm should be enough in this case so.
Thanks :)
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CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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Unread postAuthor: CpTn_lAw » Sat Mar 31, 2012 4:18 pm

I'd back up petitlu on soda cans, i use one layer and i need to score it a little for it to break at 10x. 12x however is no problem.
Soda cans can rupture badly. Only half of it can go out of the barrel and you need to consider it like a projectile on its own, at least for a few meters!
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Unread postAuthor: Petitlu » Sat Mar 31, 2012 4:28 pm

ThorJack with the cutting disc and total very well to MIX10.
As I glue on a washer, it stays in place and does not leave from the side
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Unread postAuthor: wyz2285 » Sat Mar 31, 2012 4:56 pm

So I will need to start drinking canned sodas :lol: also convince my dad to drink canned beer as well :lol:
glue it to a washer every time ?! That will consume a lot of super glue for sure... Hope it's not necessary.
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CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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Unread postAuthor: Petitlu » Sat Mar 31, 2012 5:03 pm

:D

3 drops is enough!
you can take aluminum cans too!
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Unread postAuthor: Moonbogg » Sun Apr 01, 2012 8:30 pm

I noticed what your cannon did on your second video when it didn't fire. Sometimes mine does that also and I was wondering if it's from a bad mix, or too strong of a burst disc. What do you think? Mine makes that same kind of noise.
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Unread postAuthor: wyz2285 » Mon Apr 02, 2012 5:04 am

I would say too strong burst disc combined with slightly bad mix, because at mix 5, the highest pressure after ignition would be around 300 psi, before the mix the burst disc need to be strong enough to hold 75 psi safely, so lets say 100 psi min or when miss fire, even more, so the difference it´s only 200 or less, with a bad mix. I use strong burst disc so there won´t be any danger when I loading the projectile.
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CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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Unread postAuthor: Goats spudz » Mon Apr 02, 2012 8:13 am

wyz2285 wrote:I would say too strong burst disc combined with slightly bad mix, because at mix 5, the highest pressure after ignition would be around 300 psi, before the mix the burst disc need to be strong enough to hold 75 psi safely, so lets say 100 psi min or when miss fire, even more, so the difference it´s only 200 or less, with a bad mix. I use strong burst disc so there won´t be any danger when I loading the projectile.


a standard aluminium coke can rupturs at about 1000 psi when locked between a hydraulic nipple.
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Unread postAuthor: wyz2285 » Mon Apr 02, 2012 9:41 am

a standard aluminium coke can rupturs at about 1000 psi when locked between a hydraulic nipple.

What :shock: ?? so Petitlu´s hybrid at 10x produces >1000 psi??
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CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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Unread postAuthor: Petitlu » Mon Apr 02, 2012 10:06 am

At MIX10, according HGDT the chamber pressure is 76bar (1100psi)
the rupture disc steel cans, broken to 50bar (725psi)


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Unread postAuthor: wyz2285 » Mon Apr 02, 2012 10:14 am

wow, didn´t know that :o so mix 10 actually gives me a good number... :D
Now, adjusting the spark for mix 10 :twisted:
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CpTn_lAw wrote::D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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Unread postAuthor: Petitlu » Mon Apr 02, 2012 10:33 am

with flash ignition, the gap should not exceed 0.5mm (0.02 ")
Finally, I think you must know it...
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Unread postAuthor: MrCrowley » Mon Apr 02, 2012 3:36 pm

Goats spudz wrote:a standard aluminium coke can rupturs at about 1000 psi when locked between a hydraulic nipple.
Depends on the diameter of the nipple :wink:

I use 4 for a 10x mix in a 3/4" union.
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Unread postAuthor: jackssmirkingrevenge » Mon Apr 09, 2012 12:09 am

Petitlu wrote:As I glue on a washer, it stays in place and does not leave from the side


Odd... a good o-ring should suffice to hold it in place, but it depends on your threaded fitting.
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Unread postAuthor: Petitlu » Mon Apr 09, 2012 4:00 am

I put a flat joint!

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