That's why I suggested the sandbags.Fnord wrote: Hunter, he's putting 200bar of fuel/air mix in and igniting it, meaning the pressure will jump to something like 1400-1600 bar when it combusts. Not sure if you caught that, just clarifying.
P-Mix200
I know he has a high risk of explosion!
I'll be shooting Mix100 first, then a Mix200 ...
For the ignition I thought of a spark plug-filament reduced model.
I make this hybrid for science, to satisfy my curiosity but the tests will be done safely!
I may have a problem for the mix as the room is small so if you have any advice ...
I'll be shooting Mix100 first, then a Mix200 ...
For the ignition I thought of a spark plug-filament reduced model.
I make this hybrid for science, to satisfy my curiosity but the tests will be done safely!
I may have a problem for the mix as the room is small so if you have any advice ...
Nice to see it finally occurring to someone else that building hybrids running >100X doesn't require witchcraft 
The major design issues with such a hybrid are as follows:
1. Fueling port valve. Pretty much any ball valve, including those rated for 1000 bar, will be destroyed by this application. Use a needle valve with metal-on-metal sealing and the "point" of the needle toward the high pressure side.
2. Burst disc. You'll need a sheet metal disk for this, preferably a "scored" disc which doesn't follow the projectile out the barrel (It looks like a "+" sign cut into the face of the disc). Larda's hybrid didn't do this, but instead used thinner discs which ruptured at lower pressure (and thus decreased performance in some cases).
3. Holding the burst disc. I'd be concerned about even a 6000# (the highest rated "standard" unions available in the US, rated to about 400 bar) union surviving 200X shots. A good high pressure union will probably be fine at 100X though, it's just a matter of seeing how high you can push it (from a safe distance). There's also the option of having a custom machined part made for this.
4. Barrel. Not really much of a choice here. If you haven't already decided to use seamless hydraulic tube... use seamless hydraulic tube.
5. Ignition. Looks like you've already got this pretty much sorted out.
I have quite a bit of experience in the design of high pressure hybrids. If you run into any trouble, just PM me. I'd be happy to help. I don't have much experience with air/propane mixes in very small chambers though - you'll want to talk to SB15 about that, if you end up having mixing problems. He's something of an expert in that field, and he would be very willing to assist you on this
The major design issues with such a hybrid are as follows:
1. Fueling port valve. Pretty much any ball valve, including those rated for 1000 bar, will be destroyed by this application. Use a needle valve with metal-on-metal sealing and the "point" of the needle toward the high pressure side.
2. Burst disc. You'll need a sheet metal disk for this, preferably a "scored" disc which doesn't follow the projectile out the barrel (It looks like a "+" sign cut into the face of the disc). Larda's hybrid didn't do this, but instead used thinner discs which ruptured at lower pressure (and thus decreased performance in some cases).
3. Holding the burst disc. I'd be concerned about even a 6000# (the highest rated "standard" unions available in the US, rated to about 400 bar) union surviving 200X shots. A good high pressure union will probably be fine at 100X though, it's just a matter of seeing how high you can push it (from a safe distance). There's also the option of having a custom machined part made for this.
4. Barrel. Not really much of a choice here. If you haven't already decided to use seamless hydraulic tube... use seamless hydraulic tube.
5. Ignition. Looks like you've already got this pretty much sorted out.
I have quite a bit of experience in the design of high pressure hybrids. If you run into any trouble, just PM me. I'd be happy to help. I don't have much experience with air/propane mixes in very small chambers though - you'll want to talk to SB15 about that, if you end up having mixing problems. He's something of an expert in that field, and he would be very willing to assist you on this
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
Wouuaaahhh .... everything!
I may be a solution for harbor fueling valve
A quick coupling eighth itself surrounded by a reduction fitting which is closed by a plug ...
And a rifled cal.50 black powder, it would be good?
I will see to the mixture ..
Thank you
I may be a solution for harbor fueling valve
A quick coupling eighth itself surrounded by a reduction fitting which is closed by a plug ...
And a rifled cal.50 black powder, it would be good?
I will see to the mixture ..
Thank you
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SpudFarm
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Good luck, I think it might be possible that this holds up. I wouldn`t hold it but its right there on the limit.
I work with hydraulics and you would be amazed to see the wear parts sustain before they fail under normal hydraulic applications (250Bar)
However, I personally would make something to keep everything in place and dampen shock both by the combustion pressure and the thing recoiling into things. a pipe on the outside of it with lead cast inside it around the chamber or something. However, this is just a thought.
Looking forward to the tests, document it well and find a worthy target and projectile on the first test incase it is the last!
I work with hydraulics and you would be amazed to see the wear parts sustain before they fail under normal hydraulic applications (250Bar)
However, I personally would make something to keep everything in place and dampen shock both by the combustion pressure and the thing recoiling into things. a pipe on the outside of it with lead cast inside it around the chamber or something. However, this is just a thought.
Looking forward to the tests, document it well and find a worthy target and projectile on the first test incase it is the last!
"Made in France"
- A spud gun insurance.
- A spud gun insurance.
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warhead052
- Staff Sergeant 3
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SpudFarm
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Good luck, if it works as expected, try the highest mix you can
You might actually be able to impress DYI with a 200x BB shot, and he`s hard to rival with in that playfield!
You might actually be able to impress DYI with a 200x BB shot, and he`s hard to rival with in that playfield!
"Made in France"
- A spud gun insurance.
- A spud gun insurance.
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SpudFarm
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Atleast I think your doing good. You dare to try the (Almost) untried, and that`s what progress is made of.
Also think you have very good build quality, seems like you take your time.
Also think you have very good build quality, seems like you take your time.
"Made in France"
- A spud gun insurance.
- A spud gun insurance.
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jackssmirkingrevenge
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Looks like something out of "Alien" 
hectmarr wrote:You have to make many weapons, because this field is long and short life