valve setup in Hybrid?
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pyromanic13
- Corporal 5
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- Joined: Wed Oct 19, 2005 7:54 pm
you don't time any valve. you use a burst disk
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Pete Zaria
- Corporal 5
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- Location: Near Seattle, WA
No offense intended, jjjd, but please don't even think about building a hybrid yet. You need to spend *a lot* of time researching first.
1) Hybrids, as of yet, do not use "valves"; they use burst disks. A burst disk is simply a layer of material between the barrel and chamber that holds the fuel mixture inside the chamber. When it ignites, the pressure in the chamber raises high enough to blow out the burst disk - thus why it's called a burst disk.
The reason you can't use a valve (like a piston or modified sprinkler valve) is because if something went wrong and the valve did not trigger at the exact same time that the mixture ignited, it would be called a "pipe bomb".
2) A sprinkler valve is rated for 125psi. They can handle 150 max. Hybrids can produce well over 250, so obviously a sprinkler valve could not stand the abuse. There are prototypes for "no-burst-disk-hybrids" but to the extent of my knowledge one has not yet been built. The prototypes use special seals or spring piston type systems to keep the fuel/air mix in before detonation, and are pressure-activated to avoid any potential electrical problems creating a "pipe bomb" situation.
3) Read up on hybrids at our hybrid showcase and on the wiki. It's a simple concept once you understand it. I really don't mean to offend you at all, but when people ask questions about hybrids without researching them at all, it makes me think "Damn I hope he doesn't try to build one without researching it first". Nobody likes dead forum members.
Peace,
Pete Zaria.
1) Hybrids, as of yet, do not use "valves"; they use burst disks. A burst disk is simply a layer of material between the barrel and chamber that holds the fuel mixture inside the chamber. When it ignites, the pressure in the chamber raises high enough to blow out the burst disk - thus why it's called a burst disk.
The reason you can't use a valve (like a piston or modified sprinkler valve) is because if something went wrong and the valve did not trigger at the exact same time that the mixture ignited, it would be called a "pipe bomb".
2) A sprinkler valve is rated for 125psi. They can handle 150 max. Hybrids can produce well over 250, so obviously a sprinkler valve could not stand the abuse. There are prototypes for "no-burst-disk-hybrids" but to the extent of my knowledge one has not yet been built. The prototypes use special seals or spring piston type systems to keep the fuel/air mix in before detonation, and are pressure-activated to avoid any potential electrical problems creating a "pipe bomb" situation.
3) Read up on hybrids at our hybrid showcase and on the wiki. It's a simple concept once you understand it. I really don't mean to offend you at all, but when people ask questions about hybrids without researching them at all, it makes me think "Damn I hope he doesn't try to build one without researching it first". Nobody likes dead forum members.
Peace,
Pete Zaria.
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Pete Zaria
- Corporal 5
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- Joined: Fri Mar 31, 2006 6:04 pm
- Location: Near Seattle, WA
Well thats the general concept, yes.
First of all, you must build a hybrid out of PRESSURE-RATED PIPE. No ABS, no cell core, no DWV, sch40 or 80 NSF-PW only. Sch80 is really best. Every single part on the chamber and union should be rated to AT LEAST 200psi.
The ignition system in a hybrid is also more delicate than in a regular combustion - the spark gaps have to be closer, and more sparks is always better. Stun guns are recommended.
The fuel metering system also has to be carefully constructed. Multiple safeties and a remote ignition system are great ideas.
What compressed air source do you intend to use?
Peace,
Pete Zaria.
First of all, you must build a hybrid out of PRESSURE-RATED PIPE. No ABS, no cell core, no DWV, sch40 or 80 NSF-PW only. Sch80 is really best. Every single part on the chamber and union should be rated to AT LEAST 200psi.
The ignition system in a hybrid is also more delicate than in a regular combustion - the spark gaps have to be closer, and more sparks is always better. Stun guns are recommended.
The fuel metering system also has to be carefully constructed. Multiple safeties and a remote ignition system are great ideas.
What compressed air source do you intend to use?
Peace,
Pete Zaria.
Most likely just a bike pump, My next gun is going to be a regular combustion with sch 40 pvc. im making it an over under rifel style, a 3" combustion that goes to a 1.5" stock and such, and i am then conecting it to one of the bolts and golfball barrels off of bc arms. just befor the bolt i plan to add a union so if i ever want i can make it a phnematic or hybrid
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Pete Zaria
- Corporal 5
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- Location: Near Seattle, WA
Make sure all your fittings are NSF-PW. Use couplers and bushings, not reducers. Etc...
Sounds like a good plan. Let me know how it goes.
Glad to see you're researching.
Peace,
Pete Zaria.
Sounds like a good plan. Let me know how it goes.
Glad to see you're researching.
Peace,
Pete Zaria.
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rna_duelers
- Staff Sergeant 3
- Posts: 1739
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- Location: G-land Australia
Just for the records Pete Zaria there are piston valved hybrids not only burst disk.
Dealing with hybrids with only a hand full of skills is not smart you have to be very confident with your skills and knowing that if you get it wrong could be fatal or maim easily.
Sch80(or PN18) is to me the minimal that should be used but even then I would much rather use steel or aluminium just for the added safety but it is upto you.Hope fully we can guide you so dont injure yourself but play it smart,learn as much as you can and them some more then try for a hybrid.
Dealing with hybrids with only a hand full of skills is not smart you have to be very confident with your skills and knowing that if you get it wrong could be fatal or maim easily.
Sch80(or PN18) is to me the minimal that should be used but even then I would much rather use steel or aluminium just for the added safety but it is upto you.Hope fully we can guide you so dont injure yourself but play it smart,learn as much as you can and them some more then try for a hybrid.
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Pete Zaria
- Corporal 5
- Posts: 954
- Joined: Fri Mar 31, 2006 6:04 pm
- Location: Near Seattle, WA
RNA,
I've seen diagrams and schematics for piston valved and spring-diaphragm operated hybrid guns, but have never seen images of a finished one. Has one been completed? If so, do you have a link? I'd love to see.
Peace,
Pete Zaria.
I've seen diagrams and schematics for piston valved and spring-diaphragm operated hybrid guns, but have never seen images of a finished one. Has one been completed? If so, do you have a link? I'd love to see.
Peace,
Pete Zaria.
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squeaks
- Specialist 3
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- Joined: Sun Oct 01, 2006 5:45 pm
- Location: Enoch, UT(next to Cedar City)
yeah, just to reiterate rna_duelers, sch40 pipe is not recomended for a hybrid gun. If you went anywhere over a 2x mix with sch40 you're risking your life on it. Sch80 is much safer and has been taken to 4x mixes constantly and safely and on rare(and may I say risky) occasions been taken to 6x. I don't think that you should go any further than 4x with sch80 ever. With aluminum or steel you should be safe going that high though.
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judgment_arms
- Sergeant 3
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2inch SCH40 PVC is rated to 280psi, wouldn’t that be safe for a hybrid seeing how they don’t go much past 250psi, or so you say. Yes that would give you a small safety window, but, that’s why I asked.