SpudFiles

Ah yes, that was the small version, this is the large size

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:bounce: :bounce: :bounce: Between your Jack and farcticox1 have inspired me to call the future prototype "FRANKY"
Speaking a bit about the "Franky", I am rapidly manufacturing the automatic ammunition loading system. I'm going to use 6mm airsoft balls to test, since they are not very harmful, if you keep in mind that I'm on top of the "little monster" circulating in front and back and sides. When I have it ready, I film it and show it to them. 8)

I have integrated into the "Franky" a 6mm airsoft ammunition loading system, test. It is simply the same system that I have in the combustion weapons that I have built, but in this case, moved by a pneumatic actuator, commanded by the electro valve. It is of improvised construction, but it works correctly. With this, the design concept tests are concluded. As soon as I can, I'll upload the video of this working.

The horrible noise that is heard is a check valve that sounds .... It is the Franky that begins to breathe !!
On the other hand I had to move before, and with more care, the small 100 mm long gun, so that all the holes do not coincide in the same point
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Hello can i get more information about it.

dturner wrote:Hello can i get more information about it.

Hi. Yes, what you want to know about this experiment, just ask me. I have tried to leave all the information in this post.
Apart from this, I see that you are new. You are welcome!

Just wow, really amazing to see this in action. You have succeeded where so many others have not even dared to try, kudos!

jackssmirkingrevenge wrote:Just wow, really amazing to see this in action. You have succeeded where so many others have not even dared to try, kudos!

Thanks Jack! Actually I think that few are interested in complicating the experience of doing something simple and shoot, with a thing like this that I show here. It is an experiment that I wanted to do so as not to be left alone with drawings. In the future I will try to build a prototype with the data that I have compiled neatly from all these experiences that interest me and are very much in themselves. There is still a LOT to simplify and optimize but until now, at least I have a real idea of what the problems of a semi-auto hybrid are. I am in the stage of experimenting, and I still have to try two or three more ideas, which I am thinking about. I play in this way simply because I like to experiment.

This is an obvious simplification of design. Avoid using a piston rod that scans burned gases and a spring. It works better than the spring. The only precaution is to give the right minimum pressure to the left part of the combustion chamber, where there is only air, because the blow it gives when the pressure of the air - gas mixture disappears, at the moment of the explosion, is very strong . I have not differentiated the sound of the explosion of the shock sound of the piston against the limit of the combustion chamber, when it returns. I have pressurized it with 0.6 bar, and it is more than enough to fulfill its function.

This is a new line of work to experiment with hybrids. It has nothing to do with all of the above.


Self-compressed hybrid with two combustion chambers 8) 8)

It would be based on this article of a Norwegian, very interesting reading, but of course, a simple amateur like me can not get to the heart of the mathematics that you see there. From to

An issue that catches my attention because of the possibilities it has for two things:
1- boost combustion weapons
2- Achieve compress a hybrid with this technique.
I have done some elementary tests with this information, without much scientific rigor, only by way of testing ... I have observed that indeed, and sometimes, the results are approximately according to what the theory proposes.
The first combustion chamber provides energy to the second, by transferring pressure and heat energy, achieving a compression of the air-fuel mixture in the second combustion chamber, hence the increase in gas pressure and velocity at the end, that is what propels the projectile. The ignition is located only in the primary chamber.
According to the results of experiences made by different authors on this subject, pressures up to 10 times the pressure in the secondary chamber are achieved. The geometry of the two chambers, the area of the transfer hole, and other factors determine the resulting compression increase. Without a doubt, it is worth seeing what it is about and trying more.
I have built for these basic tests, a pair of small combustion weapons that I have fired with a single combustion chamber, and with two combustion chambers coupled together, with a transfer hole between them of about 5 mm.
When I shot with the double camera the power increases a lot, and this is because in the small second chamber, the mixture is compressed before burning, which turns all this into a self-compressed hybrid.
I suspect that with the just relation of volume between both combustion chambers, and with the just area of ​​the communication hole between both, greater compressions can be achieved, with a system as simple as that of a simple combustion gun.
What I have to do, is compare the velocities of the projectiles in both cases, to know how much more energy they have.
This is the complete article that I have already left here a long time ago. I upload it again.

https://bora.uib.no/handle/1956/1325

You mean a two stage light gas gun, but with a second chamber that ignites by compression like a diesel engine?

I think they work in different ways. In the soft gas gun there is no transfer of thermal energy to the second chamber that is not combustion, rather it contains the piston that accelerates the light gas that drives the ammunition.
In this question that I comment, there is a stoichiometric mixture in both chambers. communicated by a small hole.
When the largest chamber, where the ignition is, the primary explodes, the high-velocity gases pass through the small orifice, (how small is something that I am trying to generalize by seeing the results of the author's experiments, since it is a factor critical for the effect to occur),), and as they are extremely turbulent, they contribute energy to the second chamber, the small one. There, a compression of the mixture occurs before and during combustion. The result is that in the secondary chamber, the combustible air mixture burns compressed, and the power increases. The key is that the flow is as turbulent as possible. Of course, the slower the fuel burns, the longer it takes for the mixture to be compressed in the secondary chamber.
I told you that I exploded very close recently, a PET plate of those hard plastic, in a test I was doing .... it left me deaf .... I had never exploited this type of 60 cm3 container with a mixture of air and ethyl alcohol. I used it as the secondary chamber of an aerosol container of 200 cm3 and could not stand it.
Be careful with the final part of the second chamber, where the cannon will go.
The age of one makes one take unconscious precautions sometimes, because PET plastic does not fragment ...
Jack reads the text quickly, and tell me what you think. Personally, I think it is possible to use it as an application in the Spud launchers and others, you have to do tests.

Some information that I think is relevant

OK, I understand this a bit better now, good find!

pdf link to the study for those interested.

The pressure spike in the secondary chamber really is quite impressive, it looks like this could be a legitimate way of boosting energies from a hybrid without necessarily increasing mix number. If I understood correctly the tests were carried out in closed chambers, which means that having the secondary chamber open to a barrel changes the dynamic somewhat if you are using an atmospheric combustion, but of course in a hybrid you would be using a burst disk.