HA-VI

[hectmarr]

I am trying some ideas to simplify my weapons as much as possible.
This new sistem has the following advantages:
1- It has no piston
2- It has no spring
3- It does not have a rupture disc
4- It has no solenoid valve
5- It has no dead spaces between the combustion chamber and the firing barrel

The 1/4 "steel bb`s charger is magnetic so it has no battery. Just a pair of neodymium magnets.
The combustion chamber is cleaned by a small amount of accumulated aire that enters 6 bar, which is the pressure that triggers the prototype. When injected with this pressure into the combustion chamber, after firing, the required amount of air is very little about 30 cm3. Previously, I injected air without pressure, that is, at much less speed and it was necessary, in the past, much more air that damages autonomy.

After testing many times a simple oring of the appropriate size, it is enough to retain the butane air mixture inside the combustion chamber safely, so no other system such as rupture disc, piston, or valve is necessary.
In the diagram it is seen that there are no dead spaces between the cimbustión chamber and the barrel, so this problem does not exist here.

The pneumatic system does not use an electrovalve, which eliminates, in the future, having to work up to 7X, which is what these valves for public use support. Everything is in the diagram.
References:
A- Butane volumetric dispenser
B- Butane accumulator
C- Three-way, two-position valve, actuated by air pressure (normally closed).
D- Three-way valve, supply.
E- Air accumulator to clean the combustion chamber of burned gases.

The bb`s charger uses two main magnets, which drag the steel body that seals and opens the bb`s charger, through the combustion chamber, which does not have any mechanical contact with the magnets.
You need two main magnets, to keep the forces balanced in the steel core with the walls of the combustion chamber. I have tried using only one, but having only one-sided attraction, the friction is a lot and tends to get stuck. The magnets with 12 mm prisms of 20 mm x 10 mm x 10 mm, very powerful.
The secondary magnet, the small one, is in charge of only one bb entering the chamber, because by anchoring it to the wall of the combustion chamber, it does not give rise to another occupying that same place. Batteries and solenoids are no longer required. The central body exerts enough force to press the bb a little against the retention oring.
The ammunition carrier tube is part of the combustion chamber. The reason is simple. When this tube is not under pressure and it opens suddenly when combustion occurs, the spring that compresses the bb`s is destroyed because the balls try to use the tube as a "secondary firing gun" ... The solution is to let it be part of the combustion chamber, and the small spring does not suffer much. It is like in the drawing.

I leave a pictures of the experiment weapon. The woods are dear to me, because they are the first autonomous hybrid I built. It is still useful for me to test the designs.
Soon, I will record a video to clarify everything.

Cargador bb´s magnético.png (18.75 KiB) Viewed 16316 times

[hectmarr]

I have prepared an animation of the pneumatic system. The explanation is as follows. I hope my explanation is understandable ...
In the first table: When the valve is opened, the mixture is charged in the combustion chamber and at the same time, the accumulator is charged with pressurized gas. The valve lets the gas through because it is activated by compressed air, but it cannot enter the dispenser, because the air pressure is higher than that of butane.

In the second table: When the main valve is closed, the dispenser remains at atmospheric pressure. All surplus gas escapes via line 3 of the main valve. At the same time, the gas inlet of the tank is blocked because the gas valve is closed.

In Table 3: After firing, the accumulated compressed air sweeps the burned gases out of the combustion chamber and out through the firing barrel. The gas inlet is blocked and compressed air is blocked by the closed main valve.

[jackssmirkingrevenge]

Re-hosted the image so it appears animated in the thread:



A simple idea but at the same time complex in its execution... it looks like it should work!

[hectmarr]

If it works well. It is quite difficult to explain, this for me. The dynamics of the gases in the system is like in a two-stroke piston engine, where the mixture intake and the exhaust coexist at the same time inside the cylinder, something similar. Thanks Jack for hanging up the animation.

[hectmarr]

Running some tests with the system presented here, I have noticed that for the same pressure, there are differences when using this system and pumping with the manual air pump. I think that the energy of the shot is greater when compressing with the manual pump because the mixture charge takes more time to homogenize.
With the manual pump, I have to give 6 pumps, which is more or less 1 second per pump, and what is observed is that the energy is higher, approximately 30%. the filling process lasts a total of 6 seconds, and occurs by "pulses" of air, (in each pumping), which apparently is very beneficial to achieve a uniform mixture.
With the system, the one in the drawings here, with an air reservoir, the mixture is loaded in less than 1 sec, probably about 0.5 seconds, and the mixture, inside the combustion chamber, is not as uniform, and the energy of the shot is lower ...
In both cases, the weapon is exactly the same, with the same amount of air and butane, and the same pressure, about 7X. The only thing that is different is the way the mixture enters the combustion chamber. I guess I'll have to think of a simple way to achieve homogenization in a very fast injection.
Another determining variable appears. It is not only necessary a good stoichiometric mixture, the method is equally important, and the way in which it is introduced into the combustion chamber.

[jackssmirkingrevenge]

Ah good, he's still alive!

Interesting observations. I always figured that in hybrids, since the mixture is pressurized the homogeneity is achieved without the need for further mixing. Have you tried filling from the reservoir and leaving it for a few minutes to see if it makes a difference?

[hectmarr]

Alive and kicking!
I have not tried, and it seems like a good idea to diagnose and compare.
I think that the most important thing to unify the air and the fuel is to generate a lot of turbulence between the two components, for this reason the manual pump wins, because it generates, in this particular case, 6 times turbulence, one for each pumping, against one single fast charge with deposit. I'll do the test by letting the mixture rest for about 30 or 40 seconds.

[bravootome]

it past over 1 year and still cant figure out how to make a new topic ,, admin explained me couple of times but i just cant find "new topic" like it was old times

any how i'll ask here, where the heck do i get particles of dust inside barrel ( accuracy issue ), unscrewed airtank couple of times and lot of dust on the walls . i cleaned it pretty well, put it back, and after 30 shoot same problem. i did this like 30 times on and on. where from all this dust ? the first 10 shoots after each clean are : "i shoot a cherry" by 20 m , then, " i try to shoot a watermelon " by 5 m..........
air tank is a stainless steel pipe welded by me, i welded another one thinking dust is particles from welding, air source is fridge compressor 60-70 bar. i improvised an air filter inside the fitting of the compressor- no effect............ what else should i do ?

[hectmarr]

You can check your question here: viewforum.php?f=5
This place is for serious questions, "Short question topic".
It may happen that the refrigerator compressor is dirty inside. I removed a black residue from mine that obstructed the entire airflow and fouled the entire weapon.

[hectmarr]

it past over 1 year and still cant figure out how to make a new topic ,, admin explained me couple of times but i just cant find "new topic" like it was old times

any how i'll ask here, where the heck do i get particles of dust inside barrel ( accuracy issue ), unscrewed airtank couple of times and lot of dust on the walls . i cleaned it pretty well, put it back, and after 30 shoot same problem. i did this like 30 times on and on. where from all this dust ? the first 10 shoots after each clean are : "i shoot a cherry" by 20 m , then, " i try to shoot a watermelon " by 5 m..........
air tank is a stainless steel pipe welded by me, i welded another one thinking dust is particles from welding, air source is fridge compressor 60-70 bar. i improvised an air filter inside the fitting of the compressor- no effect............ what else should i do ?

Go to the link that I show you in my previous answer and "New topic" you will find it where the orange circle is, in the screenshot.

[hectmarr]

Ah good, he's still alive!

Interesting observations. I always figured that in hybrids, since the mixture is pressurized the homogeneity is achieved without the need for further mixing. Have you tried filling from the reservoir and leaving it for a few minutes to see if it makes a difference?

I did tests by letting the compressed mixture rest for about 30 seconds, and the thing shoots with more energy, without a doubt. The wait-and-see technique is a "leaden water lifesaver" because my semiautomatic fires every 3 seconds, and I feel like waiting that long is forever.
I will try to include a toroidal turbulator, to mix the fuel and air much more, during the 0.5 seconds it takes to enter the combustion chamber using a compressed air tank. We'll see what turns out ...

[jackssmirkingrevenge]

I will try to include a toroidal turbulator, to mix the fuel and air much more, during the 0.5 seconds it takes to enter the combustion chamber using a compressed air tank.

That sounds like a good idea, mixing without needing an active fan or similar in the chamber.