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Post by the light works on Dec 30, 2016 16:54:50 GMT
it occurred to me yesterday whether it would be possible to engineer a diesel fueled machine gun.
to qualify, it would have to generate comparable muzzle energy to traditional firearms, use a liquid fuel similar to diesel fuel, and operate without an external power source, including manually cycling the action.
obviously for legal reasons I don't expect this to be anything more than a theoretical discussion.
the basis for the concept is that high performance spring-air rifles have been known to "diesel" if the wrong lubricants are used, or even to have been deliberately "dieseled" by using a drop of oil in the hollow skirt of the pellet.
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Post by GTCGreg on Dec 30, 2016 19:30:41 GMT
it occurred to me yesterday whether it would be possible to engineer a diesel fueled machine gun. to qualify, it would have to generate comparable muzzle energy to traditional firearms, use a liquid fuel similar to diesel fuel, and operate without an external power source, including manually cycling the action. obviously for legal reasons I don't expect this to be anything more than a theoretical discussion. the basis for the concept is that high performance spring-air rifles have been known to "diesel" if the wrong lubricants are used, or even to have been deliberately "dieseled" by using a drop of oil in the hollow skirt of the pellet. I doubt you could ever get the burn velocity high enough using liquid fuel compared to that of gun power. About the best you're going to get is a spud cannon. |
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Post by the light works on Dec 31, 2016 2:04:27 GMT
it occurred to me yesterday whether it would be possible to engineer a diesel fueled machine gun. to qualify, it would have to generate comparable muzzle energy to traditional firearms, use a liquid fuel similar to diesel fuel, and operate without an external power source, including manually cycling the action. obviously for legal reasons I don't expect this to be anything more than a theoretical discussion. the basis for the concept is that high performance spring-air rifles have been known to "diesel" if the wrong lubricants are used, or even to have been deliberately "dieseled" by using a drop of oil in the hollow skirt of the pellet. I doubt you could ever get the burn velocity high enough using liquid fuel compared to that of gun power. About the best you're going to get is a spud cannon. keep in mind uncontained gunpowder has a pretty low burn velocity. and you're not inherently limited to spud gun technology. |
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Post by silverdragon on Dec 31, 2016 11:51:22 GMT
Diesel or Petrol.
I ask because its not improbable that Petrol could be used at a high enough compression.
Second, the magic 14:1 ratio of air to fuel, how to ensure that. No liquid fuel will go bang without an external oxygen supply and ignition source, or even treat Diesel to a lot of bad treatment before it complains.
How to test this, hammer the [cr@p] out of a tin of petrol, it wont explode until the can splits, in that you can bounce a tank of petrol or diesel about in a most scary way before it goes bang.
How to aerosol the fuel to ensure it mixes with the air.
However, if you could MacGuyver an engine to get the parts in the right order, firing a round off the exhaust stroke of a high compression engine, I think you may qualify as a type of machine gun off that.
As most of the muzzle velocity would be being used to fire the round, I am wondering if your going to need a second engine to turn over the barrels of the ones doing the firing, and supply enough power to cycle in the rounds to the exhaust barrels.
However, you have started me thinking, and that can only mean one thing...
When do we start the build?.
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Post by the light works on Dec 31, 2016 13:12:51 GMT
Diesel or Petrol. I ask because its not improbable that Petrol could be used at a high enough compression. Second, the magic 14:1 ratio of air to fuel, how to ensure that. No liquid fuel will go bang without an external oxygen supply and ignition source, or even treat Diesel to a lot of bad treatment before it complains. How to test this, hammer the [cr@p] out of a tin of petrol, it wont explode until the can splits, in that you can bounce a tank of petrol or diesel about in a most scary way before it goes bang. How to aerosol the fuel to ensure it mixes with the air. However, if you could MacGuyver an engine to get the parts in the right order, firing a round off the exhaust stroke of a high compression engine, I think you may qualify as a type of machine gun off that. As most of the muzzle velocity would be being used to fire the round, I am wondering if your going to need a second engine to turn over the barrels of the ones doing the firing, and supply enough power to cycle in the rounds to the exhaust barrels. However, you have started me thinking, and that can only mean one thing... When do we start the build?. here is one of the more objective youtube videos on the subject. as you can see, not much aerosolization required. |
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Post by Cybermortis on Dec 31, 2016 17:29:20 GMT
Diesel or Petrol. I ask because its not improbable that Petrol could be used at a high enough compression. Second, the magic 14:1 ratio of air to fuel, how to ensure that. No liquid fuel will go bang without an external oxygen supply and ignition source, or even treat Diesel to a lot of bad treatment before it complains. How to test this, hammer the [cr@p] out of a tin of petrol, it wont explode until the can splits, in that you can bounce a tank of petrol or diesel about in a most scary way before it goes bang. How to aerosol the fuel to ensure it mixes with the air. However, if you could MacGuyver an engine to get the parts in the right order, firing a round off the exhaust stroke of a high compression engine, I think you may qualify as a type of machine gun off that. As most of the muzzle velocity would be being used to fire the round, I am wondering if your going to need a second engine to turn over the barrels of the ones doing the firing, and supply enough power to cycle in the rounds to the exhaust barrels. However, you have started me thinking, and that can only mean one thing... When do we start the build?. Semiautomatic weapons already use the recoil to cycle the action without significantly affecting the muzzle velocity. There is no reason to think designing a similar type of action, or modifying the way a combustion engine works, is impossible. For a machine gun you'd probably want to avoid full or semiautomatic actions given that you'd be dealing with a combustable fluid being sprayed into a red hot chamber. Even a bolt action runs the risk of igniting the fuel as it enters the chamber, which would result in less of a bang and more of a flamethrower and a round jamming in the barrel. That, with any kind of bolt or automatic action, would probably result in the firer getting burning fuel sprayed in their face. |
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Post by silverdragon on Jan 1, 2017 20:02:45 GMT
This is why I was suggesting maybe an engine mechanically working the cylinder that fires, maybe a slow "gear" to cycle the firing mechanism, something like the ratio that turns 1st gear to revolve one rotation of a vehicles drive wheel at 1mph kind of speed.
Automatic doesnt mean rounds per second, if you manage say between 5 to 20 rounds per min, proof of concept enough for me.
"Slow speed" with an "Eject" button as an emergency stop?.. [and a clutch to disengage as well.... ]
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Post by the light works on Jan 1, 2017 21:56:21 GMT
This is why I was suggesting maybe an engine mechanically working the cylinder that fires, maybe a slow "gear" to cycle the firing mechanism, something like the ratio that turns 1st gear to revolve one rotation of a vehicles drive wheel at 1mph kind of speed. Automatic doesnt mean rounds per second, if you manage say between 5 to 20 rounds per min, proof of concept enough for me. "Slow speed" with an "Eject" button as an emergency stop?.. [and a clutch to disengage as well.... ] that is essentially having a pony engine cycling the mechanism, which I would consider cheating. |
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Post by silverdragon on Jan 2, 2017 10:06:00 GMT
This is why I was suggesting maybe an engine mechanically working the cylinder that fires, maybe a slow "gear" to cycle the firing mechanism, something like the ratio that turns 1st gear to revolve one rotation of a vehicles drive wheel at 1mph kind of speed. Automatic doesnt mean rounds per second, if you manage say between 5 to 20 rounds per min, proof of concept enough for me. "Slow speed" with an "Eject" button as an emergency stop?.. [and a clutch to disengage as well.... ] that is essentially having a pony engine cycling the mechanism, which I would consider cheating. Why?. If a mechanism is required, why not a pony engine, to make the whole thing semi-automatic?.. All I am doing there is taking away the human interaction with what may be and has been pointed out as possibly a highly dangerous machine that has the potential of spraying super-heated fuel across the whole county... I am just upping the stakes on the semi-automatic firing mechanism. The pony engine will create fuel pressure, may even create a turbo pressure to fill the cylinder, will cycle a round, load, fire, and "Make safe" the mechanism afterwards on a push-button-retire-to-safe-distance scale?.. |
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Post by the light works on Jan 2, 2017 15:32:47 GMT
that is essentially having a pony engine cycling the mechanism, which I would consider cheating. Why?. If a mechanism is required, why not a pony engine, to make the whole thing semi-automatic?.. All I am doing there is taking away the human interaction with what may be and has been pointed out as possibly a highly dangerous machine that has the potential of spraying super-heated fuel across the whole county... I am just upping the stakes on the semi-automatic firing mechanism. The pony engine will create fuel pressure, may even create a turbo pressure to fill the cylinder, will cycle a round, load, fire, and "Make safe" the mechanism afterwards on a push-button-retire-to-safe-distance scale?.. it will also make it a motor driven gun, rather than a machine gun. kind of like a moped is not a human powered vehicle. |
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Post by Cybermortis on Jan 2, 2017 17:51:24 GMT
The issue is safety for the user, which would either limit a gasoline/diesel firearm to being a single shot weapon. Or require the use of mechanical systems to remove any risk of the user being sprayed with burning fuel.
Internal systems that utilize recoil to cycle the action can't be considered cheating, since that is exactly how semi and fully automatic weapons work. You can even make a reasonable argument that an external motor to cycle a multi-barreled weapon is hardly cheating either, as that is how miniguns work and even the earlier versions had a motor in the form of the user turning a crank.
Come to think on it, a multi-barreled design might work better than a single barrel.
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Post by the light works on Jan 2, 2017 19:41:10 GMT
The issue is safety for the user, which would either limit a gasoline/diesel firearm to being a single shot weapon. Or require the use of mechanical systems to remove any risk of the user being sprayed with burning fuel. Internal systems that utilize recoil to cycle the action can't be considered cheating, since that is exactly how semi and fully automatic weapons work. You can even make a reasonable argument that an external motor to cycle a multi-barreled weapon is hardly cheating either, as that is how miniguns work and even the earlier versions had a motor in the form of the user turning a crank. Come to think on it, a multi-barreled design might work better than a single barrel. a remote firing mechanism for testing would be a reasonable safety precaution. however, if you want to allow a pony engine, all you have to do is throw a diesel engine onto the mythbusters repeating crossbow and you can call it a machine gun. goalposts successfully moved. can we make a diesel powered device to make multiple things travel with more than 1000 foot pounds of energy? everybody that's rolled a truckload of steel girders has done that. |
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Post by the light works on Jan 2, 2017 20:38:41 GMT
here you go. a Silverdragon model liquid fueled machine gun.  |
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Post by ponytail61 on Jan 3, 2017 5:58:31 GMT
Use a caseless bullet like this one. Replace the gunpowder with diesel/oil and the brass base with a plastic one that is scored. The air pressure cracks the plastic base and allows the pressure to ignite the diesel and then the plastic base flowers out as the gas is expelled but stays attached as to not foul the barrel. Or use a sabot with the same characteristics. .jpg) The gases would cycle the action as normal to reload. For the air for combustion you could have a water canister and chemical container in the stock that mixes and fills a reservoir with air/oxygen like the air gun used by Lewis and Clark. |
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Post by the light works on Jan 3, 2017 6:35:05 GMT
Use a caseless bullet like this one. Replace the gunpowder with diesel/oil and the brass base with a plastic one that is scored. The air pressure cracks the plastic base and allows the pressure to ignite the diesel and then the plastic base flowers out as the gas is expelled but stays attached as to not foul the barrel. Or use a sabot with the same characteristics. The gases would cycle the action as normal to reload. For the air for combustion you could have a water canister and chemical container in the stock that mixes and fills a reservoir with air/oxygen like the air gun used by Lewis and Clark. still depends on recharging your oxidizer tank. the other factor brought up by a friend outside the site is how to get your piston to produce enough compression to ignite the fuel, without blowing the projectile out of the barrel. (which is to say, the piston blowing the projectile out instead of compressing the air.) one option considered was actually having the piston driven away from the target to compress the air and the firing driving the piston back to shoot the projectile; while recompressing the spring. |
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Post by Cybermortis on Jan 3, 2017 13:54:11 GMT
*Blinks*
Could you use a percussion cap to drive a plate forward to compress the fuel? Basically turning a cartridge into a single use cylinder in an engine?
Ignition of the fuel might be possible using pezo (sp?) electric crystals that would create an electrical spark when compressed by the fuel.
The upper plate, keeping the fuel and the projectile separate, could be designed to fail at a given pressure allowing the gasses to escape and push the bullet down the barrel.
We've been looking at trying to design a weapon, maybe we should be looking at the ammunition instead? Sure, a gasoline cartridge is going to be a heck of a lot larger than a conventional gunpowder cartridge. But then that was probably always going to be the case to achieve anything close to the muzzle velocity of conventional firearms.
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Post by the light works on Jan 3, 2017 15:24:30 GMT
*Blinks* Could you use a percussion cap to drive a plate forward to compress the fuel? Basically turning a cartridge into a single use cylinder in an engine? Ignition of the fuel might be possible using pezo (sp?) electric crystals that would create an electrical spark when compressed by the fuel. The upper plate, keeping the fuel and the projectile separate, could be designed to fail at a given pressure allowing the gasses to escape and push the bullet down the barrel. We've been looking at trying to design a weapon, maybe we should be looking at the ammunition instead? Sure, a gasoline cartridge is going to be a heck of a lot larger than a conventional gunpowder cartridge. But then that was probably always going to be the case to achieve anything close to the muzzle velocity of conventional firearms. I'd prefer to avoid gunpowder entirely and stick with a spring to compress the air charge. then the air charge would cause the fuel to autoignite. I would suppose a flange on the back of the projectile, designed to collapse at a set chamber pressure, would let the chamber pressure build higher before launching the projectile - and could then provide a drive skirt in the barrel. I suppose if you made a cartridge that contained the fuel in a collapsible cell would crush and disperse the fuel at the desired chamber pressure, as well. possibly in a hollow backed projectile as above, to render it caseless. |
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Post by Cybermortis on Jan 3, 2017 23:08:59 GMT
Percussion caps don't contain gunpowder, they contain a shock sensitive explosive - originally mercury fulminate. The amount used is not enough to act as a propellant itself, apart from anything else using a high explosive will turn your gun into a pipe bomb*.
(*Percussion caps were actually a spin off from attempts to produce a replacement for blackpowder...rather of lot of which was done by English clergy who had the time and money to experiment. Mercury fulminate was one of the substances they experimented with, discovering that you either ended up with the bullet getting stuck in the barrel. Or the gun would explode.
Someone later come up with the idea of using the mercury fulminate to ignite the powder, rather than as the propellant.)
You could not realistically create a spring system powerful, small and reliable enough to compress gas or fuel enough to cause an explosion. At least not for a 'cartridge'. Anything larger than that, well you'd be better off using a manual crank.
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Post by the light works on Jan 4, 2017 1:55:27 GMT
Percussion caps don't contain gunpowder, they contain a shock sensitive explosive - originally mercury fulminate. The amount used is not enough to act as a propellant itself, apart from anything else using a high explosive will turn your gun into a pipe bomb*. (*Percussion caps were actually a spin off from attempts to produce a replacement for blackpowder...rather of lot of which was done by English clergy who had the time and money to experiment. Mercury fulminate was one of the substances they experimented with, discovering that you either ended up with the bullet getting stuck in the barrel. Or the gun would explode. Someone later come up with the idea of using the mercury fulminate to ignite the powder, rather than as the propellant.) You could not realistically create a spring system powerful, small and reliable enough to compress gas or fuel enough to cause an explosion. At least not for a 'cartridge'. Anything larger than that, well you'd be better off using a manual crank. actually, high performance airguns compress the air enough that you have to use special lubricants to prevent ignition - as my video clip above demonstrates. the big question is if you can make it so it has enough force to recompress the spring, while still delivering the projectile downrange. or course, it is a stiffer spring than the recoil spring on a semiautomatic rifle; which increases the challenge. |
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Post by silverdragon on Jan 5, 2017 7:24:39 GMT
Why?. If a mechanism is required, why not a pony engine, to make the whole thing semi-automatic?.. All I am doing there is taking away the human interaction with what may be and has been pointed out as possibly a highly dangerous machine that has the potential of spraying super-heated fuel across the whole county... I am just upping the stakes on the semi-automatic firing mechanism. The pony engine will create fuel pressure, may even create a turbo pressure to fill the cylinder, will cycle a round, load, fire, and "Make safe" the mechanism afterwards on a push-button-retire-to-safe-distance scale?.. it will also make it a motor driven gun, rather than a machine gun. kind of like a moped is not a human powered vehicle. Its a gun fired by a mechanical machine attached to the gun, isnt that a machine-gun?... or is there something in the pedantics that say it has to be self powered to get that status?.. In that case, as the "Mini-gun" Rail Gun thing that MB's had fun with, 5,000 rps or whatever it is, it had an electric motor to spin the barrels, isnt that a machine aided gun as well?... The issue is safety for the user, which would either limit a gasoline/diesel firearm to being a single shot weapon. Or require the use of mechanical systems to remove any risk of the user being sprayed with burning fuel. Internal systems that utilize recoil to cycle the action can't be considered cheating, since that is exactly how semi and fully automatic weapons work. You can even make a reasonable argument that an external motor to cycle a multi-barreled weapon is hardly cheating either, as that is how miniguns work and even the earlier versions had a motor in the form of the user turning a crank. Come to think on it, a multi-barreled design might work better than a single barrel. This is why I was thinking of one engine spinning another to fire the thing that cycles air through the barrels of the firing engine when not being loaded. a remote firing mechanism for testing would be a reasonable safety precaution. however, if you want to allow a pony engine, all you have to do is throw a diesel engine onto the mythbusters repeating crossbow and you can call it a machine gun. goalposts successfully moved. can we make a diesel powered device to make multiple things travel with more than 1000 foot pounds of energy? everybody that's rolled a truckload of steel girders has done that. Remote firing is the reason why I suggested this, its keeping the whole of my machine on a remote key off system with possibilities of disengaging the clutch for an emergency stop. Both by User or the mechanism that senses a duff load, duff fire etc?.. We have the technology now to use engine sensors to note there has been a "jam" and disengage the firing system, bloody well use them?.. *Blinks* Could you use a percussion cap to drive a plate forward to compress the fuel? Basically turning a cartridge into a single use cylinder in an engine? Ignition of the fuel might be possible using pezo (sp?) electric crystals that would create an electrical spark when compressed by the fuel. The upper plate, keeping the fuel and the projectile separate, could be designed to fail at a given pressure allowing the gasses to escape and push the bullet down the barrel. We've been looking at trying to design a weapon, maybe we should be looking at the ammunition instead? Sure, a gasoline cartridge is going to be a heck of a lot larger than a conventional gunpowder cartridge. But then that was probably always going to be the case to achieve anything close to the muzzle velocity of conventional firearms. I'd prefer to avoid gunpowder entirely and stick with a spring to compress the air charge. then the air charge would cause the fuel to autoignite. I would suppose a flange on the back of the projectile, designed to collapse at a set chamber pressure, would let the chamber pressure build higher before launching the projectile - and could then provide a drive skirt in the barrel. I suppose if you made a cartridge that contained the fuel in a collapsible cell would crush and disperse the fuel at the desired chamber pressure, as well. possibly in a hollow backed projectile as above, to render it caseless. First, single use barrel round, how accurate would a short round barrel like that be?.. think safety issues?.. then you have to eject the whole round and place a new one in its place, and tighten it down or clamp it down to prevent misfire?.. Second, if your using diesel, if your running it through an already warm engine, that will help with firing the thing, because diesel likes to be warm, and the barrels of a multi-barrel system against a cold cartridge, which will fire better, because I think cold cartridges are going to fail the test if they are too cold... think of recent diesel engine discussions on the forum and the use of glow plug warmers?.. If too cold, say a snowy day in Alaska, the diesel may indeed gel-ify, and refuse to fire completely. Collapsible cells, good in theory, but again in theory, how you going to eject that?... Through the barrel may score the barrel?... May I cite KISS, Keep It Simple. Use modern technology to aid, but not hinder?.. Changing up the propellant here is just re-inventing the gun... yeah, that would work, but, this is a liquid fuel diesel gun, and how far are we getting away from that?. Using Petrol, thats one step, using other liquid propellants, maybe, but using the liquid to fire a powder gun, too many steps in the firing mechanism.?.. |
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