Small autonomous hybrid

[hectmarr]

Looks nice. Do do you have any details on how the pump connects to the chamber, like is there an isolation valve (besides the check valve in the pump) between them?

You posted the other pictures again but none of the diagrams.


PD: Saludos desde la isla de plátanos y béisbol.

When I go home, after work, I'm going to make a general diagrams of the system, and I'll upload it here along with the diagrams that are already here. It will be clear what you ask me.

The future weapon will have a magazine and will expel used cartridges, and the gas charge is fully automatic. I will publish the diagrams here to give you their opinions.

Now you're talking my language!

Yes, I'm just a musician, but NO singer !!

It was a small reference to one of my favorite Spanish youtube videos

JUAAAA !!! Very good !! :bounce: :bounce:

[hectmarr]

When the 4-way valve is closing the combustion chamber, position "A", this valve resists the combustion pressure, so it must be resistant.
This prevents the injector-doser cylinder and the filling line from being subjected to high pressure.
At the same time, it closes the line of the manometer, before the firing, so that it is not destroyed, because the pressure produced by the deflation is much higher than the maximum pressure that supports the manometer.
At the same time, in this "A" position, the 4/2 valve releases the pressure on the side of the piston in the diagram, thus remaining at atmospheric pressure to be able to go to this side when gas is recharged again.
This valve is self-built, and is reinforced with glass fabric and polyester resin. The 10ml syringe is only useful for the plunger with the o'rings to slide smoothly. The zone that supports high pressure, has double o'rings, so that it does not fail.
I have disregarded the one I am using ... The Bourdon tube exceeded its elastic limit by forgetting to manually close the line when it was performing the first tests. Stupid me

I upload the diagrams again. I hope they look better.

I hope you understand the diagram and my English as a translator. If not, let me know and I'll try again.

[mark.f]

The Bourdon tube exceeded its elastic limit by forgetting to manually close the line when it was performing the first tests. Stupid me

Seems we all have that problem at some point.

gauge.jpg (21.35 KiB) Viewed 5818 times

[jackssmirkingrevenge]

Wow, much more ingenious than I initially understood. I hadn't realized you were using burst disks on you "cartridges"!

Once again, excellent work!

[hectmarr]

Wow, much more ingenious than I initially understood. I hadn't realized you were using burst disks on you "cartridges"!

Once again, excellent work!

Hello ! Thanks again!
Yes it is. I thought I had mentioned it sometime. I'm using thin aluminum foil as a rupture disk, the kind that have cigarettes. With two disks of these the engender works


I have a question, because I am drawing the new weapon.
How much volume should the combustion chamber have? I mean what minimum volume of air should go out by the .22 caliber firing barrel?
The length of the firing barrel is hypothetically about 50 cm, about 20 ".
I have used approximately 300 ml in the prototype presented here. My question is: Until how much could this volume decrease without losing ammunition velocity in the shot? I would like to know your opinion because I have seen on youtube, in your channel, that you have made many small powerful hybrids.
I have to define this question to start dimensioning the other components.
Actually I have several doubts but for clarity, I will try to make them of one.

[jackssmirkingrevenge]

Yes it is. I thought I had mentioned it sometime. I'm using thin aluminum foil as a rupture disk, the kind that have cigarettes. With two disks of these the engender works

It was hard to comprehend from your microscopic diagrams before if you want a "healthier" alternative, I found that photo paper makes an excellent burst disk for small calibers.

How much volume should the combustion chamber have? I mean what minimum volume of air should go out by the .22 caliber firing barrel?

I think your best bet is to download D_Hall's excellent HGDT Simulation Program - this way you can put in all the parameters and have an approximate idea of the performance you will get.

[hectmarr]

Ok. I will try with photo paper, for rupture disc and to use the simulator that I already recommended to use previously. Greetings and thanks.

[hectmarr]

I was trying to make progress in this small hybrid project
Autonomous, trying to improve it.
As an improvement, the new prototype has a loading and ejection system
Of the cartridges very simple, which is in the diagram that I attached.
The other improvement is that it shoots between 5.5 and 6X.
In addition, it has associated the change of position of the distributor valve
To the movement of the cartridge loading lever.
Few steps to the next shot, that's what I'm looking for ...
I have also added a check valve that lets the flow through the
Combustion chamber, but not vice versa. This was necessary because the explosion
Is stronger and the valve distributor was sufficient in prototype 1 to
Contain the explosion pressure, you can no longer alone ...
I built it with two couplings, a 1/4 "steel ball and a small spring
To be normally closed. It worked perfectly so far.

The sequence to shoot was as follows:

1- Charge gas
2- Load the ammunition and at the same time expel the used cartridge.
3- Inject air with the pump
4- Take out insurance and PUMMMM !! :bounce: :bounce: :bounce:

As soon as I have free time, I will upload a video of how this works, I mean
System of loading and ejecting cartridges, and also upload some photos.
The woods, trigger and grips of the weapon are still to be finished.

[jackssmirkingrevenge]

Brilliant design, love it.

[hectmarr]

Easy to build is what decides if it is done, (if I can build it), or not do ... Thanks Jack.
An interesting possibility is to obtain the force necessary to lock the cartridge so that it does not lose air, and to be a more firm seal, is to exert that force with a piston and compressed air of the air pump, as it is drawn in the diagram.
The problem I am having is that the mechanical lock I am using, has to make enough force so that only 6X there are no leaks. In this way I tell you, there would be no wear and tear on the metal parts that are touching and worse pressed against each other, which is the method I am using in the present.
Likewise, with the addition of a spring can open and close the device, I mean, load and expel the ammunition not manually. Without air, it would expel the cartridge and with compressed air making force against the plunger, load the cartridge and lock on the oring. This could be commanded with a simple valve coupled to the pneumatic gun circuit.

[jackssmirkingrevenge]

Have you considered using the pressure itself to force a seal? It's a little complicated to make without a lathe as you would need o-rings but the idea is feasible, I have done it in the past.

[hectmarr]

Have you considered using the pressure itself to force a seal? It's a little complicated to make without a lathe as you would need o-rings but the idea is feasible, I have done it in the past.

Yeah right. That's what I'm interested in to improve sealing. It is more complicated, but it would be worth a try. In the drawing is the way to do it, always based on what I have built. In my case the firing barrel moves, and the option would be to adapt a piston attached to it.
I do not have a lathe, but I have in mind to make the corresponding planes of the parts that must be machined and have them built by a lathe professional. It is the only way to have something that lasts in time. For the moment I'm just trying to test and define what I'll build. This is the final idea for this project.

[hectmarr]

Have you considered using the pressure itself to force a seal? It's a little complicated to make without a lathe as you would need o-rings but the idea is feasible, I have done it in the past.

Jack: Do you have any pictures or pictures of your work on this? It would be useful for me to analyze and see what it is about. Thank you

[jackssmirkingrevenge]

Something like this:



For it to work, the piston has to be in close contact with the disk and seat before the gas is introduced so the pressure will lock it in place.

[hectmarr]

Nice idea you drew. :bounce: