HAC- II- R

[Alanstone]

Hectmarr you've done some excellent work with regard to your hybrid projects. Congratulations. I've been thinking along these lines: A https://www.ansgear.com/Ninja_Adjustabl ... -reg45.htm adjusts from 450psi. With a stoemetric ratio of 31:1, you can your flush your chamber with butane at atmospheric pressure then pressurize to 450psi and you will have a near perfect mix. After the shot, flush the chamber with butane while venting to atmosphere then pressurize to with 450PSI and you are good to go again. I've been working for a while on how to automate it and haven't solved the riddle yet. I will post some sketches when I do. Does anyone see a flaw in my idea?

[hectmarr]

Hectmarr you've done some excellent work with regard to your hybrid projects. Congratulations. I've been thinking along these lines: A https://www.ansgear.com/Ninja_Adjustabl ... -reg45.htm adjusts from 450psi. With a stoemetric ratio of 31:1, you can your flush your chamber with butane at atmospheric pressure then pressurize to 450psi and you will have a near perfect mix. After the shot, flush the chamber with butane while venting to atmosphere then pressurize to with 450PSI and you are good to go again. I've been working for a while on how to automate it and haven't solved the riddle yet. I will post some sketches when I do. Does anyone see a flaw in my idea?

Thank you!
It's too much pressure for my project. I am trying to analyze alternatives similar to this configuration that you propose, that adapt to a hybrid launcher of 10 or 15x.

[Alanstone]

Do you say the pressure is to high because of your butane measuring system?

[jackssmirkingrevenge]

With a *stoichiometric ratio of 31:1, you can your flush your chamber with butane at atmospheric pressure then pressurize to 450psi and you will have a near perfect mix. After the shot, flush the chamber with butane while venting to atmosphere then pressurize to with 450PSI and you are good to go again.

Interesting idea, no need to meter the butane because purging the chamber is sufficient, I like! Don't see why it wouldn't work in practice. One downside is that you'll probably use more fuel than necessary but it's not exactly expensive, literally a small price to pay.

I've been working for a while on how to automate it and haven't solved the riddle yet. I will post some sketches when I do. Does anyone see a flaw in my idea?

If I'm getting it right, the cycle would be as follows:

1) chamber purge valve open
2) dose butane
3) chamber purge valve close
4) pressurize chamber to 450 psi
5) ignition

Sounds like the easiest way to do it would be using solenoid valves and a microcontroller.

[hectmarr]

Do you say the pressure is to high because of your butane measuring system?

My weapon would not support that mixing pressure at the time of the explosion. I'm shooting at 5x - 7x no more. I have planned to build a more solid weapon to go up to about 15x, but at the moment everything is built for less pressure.
What you propose will certainly work, as long as the air - gas mixture is stoichiometric, regardless of the pressure used.
In my case, in the present, to work at 5x, my values are these:
Volume combustion chamber - 40 ml
Amount of butane - 10 ml
pressure mix 5 bar
amount of air - 200ml.

To work as you propose I would need
Volume combustion chamber - 10 ml
butane amount - 10ml
pressure mix 5 bar
Air quantity 200 ml.

With a 10 ml combustion chamber, the force of the shot falls a lot, I've tried it.
otherwise, to maintain my 40 ml combustion chamber volume, I would need:
combustion chamber volume - 40ml
gas volume - 40 ml!
amount of air - 800 ml
Mixing pressure - 20 bar
Surely it can be used for a hybrid of 20 x or more.
I add
I mean that a combustion chamber of 10 cm3, in my particular case, to shoot at 5X, is very small. A 20X would work very well, solving everything else. I am referring to the system of closing the weapon, piston valve, rupture disc, etc, and the method to completely clean the camera after each shot, and the method to understand the gas and then the air in an almost automatic way, just by touching a button.

[hectmarr]

With a *stoichiometric ratio of 31:1, you can your flush your chamber with butane at atmospheric pressure then pressurize to 450psi and you will have a near perfect mix. After the shot, flush the chamber with butane while venting to atmosphere then pressurize to with 450PSI and you are good to go again.

Interesting idea, no need to meter the butane because purging the chamber is sufficient, I like! Don't see why it wouldn't work in practice. One downside is that you'll probably use more fuel than necessary but it's not exactly expensive, literally a small price to pay.

I've been working for a while on how to automate it and haven't solved the riddle yet. I will post some sketches when I do. Does anyone see a flaw in my idea?

If I'm getting it right, the cycle would be as follows:

1) chamber purge valve open
2) dose butane
3) chamber purge valve close
4) pressurize chamber to 450 psi
5) ignition

Sounds like the easiest way to do it would be using solenoid valves and a microcontroller.

It's like you say. A two-way valve for the gas, and a check valve between the combustion chamber and the solenoid valve, to protect it from the explosion pressure. In the case of using cartridges that include the rupture disc, you simply load the gas before inserting the cartridge.
You load the gas
loads the cartridge
loads the air and BUM !!

[Alanstone]

In the case of using cartridges that include the rupture disc, you simply load the gas before inserting the cartridge.

Hectmarr, is the cartridge your firing chamber? If that is the case I think it's greatest benefit is being able to eject the hot cartridge. I am concerned about heat generation with my idea. I was planning to 3d print the stock but I don't know if I will be able to get rid of the heat. Also, at what pressure is your rupture disk breaking?

If I'm getting it right, the cycle would be as follows:

1) chamber purge valve open
2) dose butane
3) chamber purge valve close
4) pressurize chamber to 450 psi
5) ignition

Sounds like the easiest way to do it would be using solenoid valves and a microcontroller.

Yes that's the cycle I had in mind.

Hectmarr, I have a few more ideas I'd like to share but I don't want to hijack your topic. Should I start a new topic or should I continue here?

[hectmarr]

No. The cartridge incorporates the rupture disc, an o'ring for the seal and the ammunition. These are the diagrams:
In my case the heat is a lot. With an ambient temperature of 30 - 35 ºC and firing every 20 or 30 seconds, everything heats up very quickly because heat accumulates. Enter more calories than it dissipates because there is not much time. I shoot rounds of 4 or 5 cartridge and let it cool. The resin gets very bad with the heat.
You can continue with your project here, or open a new thread, as you prefer. I will be attentive to talk about this and help as much as I can.
This is the thread with more information:http://www.spudfiles.com/hybrid-cannons/topic26616.html

[hectmarr]

So I am shooting with the dosing unit attached to the weapon and the external air tank. I'm thinking of replacing the woods, (green), to careen everything, and that the appearance is more aesthetic. In this version, I replaced the solenoid valve with a 3/2 coolant valve with exhaust. The cartridge is simply loaded and manually activated by the mixing charge and triggered.
Actually it is a great comfort not to use a manual air pump, but it is more complicated to build.
The air tank has 150 psi, and I can shoot 30 cartridges uninterruptedly, at 6X. It drills two cans perfectly and the noise is little, so a sound suppressor is unnecessary. The noise comes from the objective, actually.