Autonomous hybrid caliber .25 Prototype 2

[hectmarr]

I am taking up the hobby of weapons and I leave some photos, diagrams etc of the new thing that I have built.
I have created a new publication for clarity, otherwise everything becomes a bit confusing.
This hybrid weapon works with 5 bar of pressure and pure butane as fuel. The firing cannon
is purchased, 24 "long, 12 micro striae and .25 caliber, 6.35mm.
It has an air pump made with a recycled shock absorber tube, just like the camera
of combustion and the support of the lever.
The system has only one hard spring, which is responsible for retaining the compressed mixture.
When combustion occurs, the increase in pressure pushes it until the spring is fully compressed
and upon discovering the exit orifice, the gases at high speed enter the firing barrel.
With this system, rupture disk is not used. The ammunition is loaded directly, as in any air gun. This simplification is what I was looking for.
The fuel dosing system is newly designed and much easier and faster to build
than the previous system.
It is based on the suction effect of the air pump, which has two valves, one to expel air and retain
and the other to suck air and retain.
When the air charge inside the air pump is produced, it sucks the gas measurement
making a premix inside the air pump. When it expels the air, it expels
the combustible gas, in the first pumping and then, only air. It is clear in the diagram that I show here.
The operation is as follows.
The gas is injected from the tank by "B", and fills the cylinder until the piston opens the hole "D".
The pressurized gas escapes through the one-way valve to the outside and only the cm3 of the cylinder remains
At atmospheric pressure, which is the dose for a good stoichiometric ratio, about 9 cm3 in this case.
When starting to move the lever of the air pump, when it sucks, it goes through "A", sucking
the measurement of gas and after discovering the hole through the piston sucks only air up to the firing pressure.
"A" and "B", are opened and closed by a small auxiliary valve that has the weapon. It is necessary that during
the gas charge, do not enter gas uncontrollably inside the pump, for this reason "A" is closed
when the gas enters, being later opened when the stage of pumping air into the combustion chamber begins.
This system is designed only to operate with an air pump with the two classic valves they have.
The main advantage is that since the system is not subjected to any pressure, a simple syringe can be used
without any failure, it is very easy and fast to manufacture. Aside it has other advantages, since they do not interfere the impreciciones
due to the compressibility of the gases, an issue that happened to me in the previous systems, where the system
It was subjected to the compression pressure of the mixture. Aperte, it is much more compact and has fewer elements.
I leave a picture of the dispenser and of an air pump similar to the one of the weapon.
I hope to make myself understood, if not, please tell me and I will try again.
When I can, in the future, I will upload a video of the weapon working. It is in my plans to increase the pressures a bit more
Let's say about 8X. The lever pump can give this without any problem.
I tried it shooting and it's quite powerful ... and noisy ... I treat it with caution because with the baline
Benjamin 6.4mm, is quite effective, and drills 5 layers of three-ply wood as paper ... or two cans,
of canned products or a duralumin door ...
Well, I wanted to comment and show this work. I would like to know what you think. I have not painted it because I'm trying. In
the future I will dedicate a little time to aesthetics, secondary issue at this time.

[jackssmirkingrevenge]

Once again an absolutely astounding effort, made even more impressive by your use of limited resources - and 8x too! It's a shame this forum is not as active as it used to be because a self-contained hybrid was a bit of a holy grail for many members.

My one criticism for a single shot device is the relatively small caliber, I would have gone for something in the 3/8" range, but then again I'm just power mad, 0.25" is plenty

a duralumin door ...

Has your wife found out about this yet

[hectmarr]

Hi Jack ! Thanks for your comment.
Unfortunate incident that cost me a scolding as if I were a silly child .... really yes! I was !! When he came from the street, he saw by magic and that kind of radar that women have to know about "other women" and strange holes in the doors. I "shot" with a penetrating 50 gauge look
The weapon is missing the bolt system to introduce the ammunition. I am working on it. The screw system is quite uncomfortable.
It would be interesting to make one of a larger caliber ... you say use steel balls? or lead ammunition? The problem in my case is the noise ... I'm tempted to do something bigger. I'll see if I can build it with a big silencer.
What interests me also, is to compress at higher pressures, as I said in the previous post about 8X, because I am with 4.5 - 5X one gets used to this and it is "necessary" more. In spite of this, it surpasses a 5.5-speed spring gun, not a "super rifle" but it is a factory made weapon and heavier and much more backward than this hybrid. Not to mention the price difference .... Mine weight 2.5 kg. I'm going to build it completely again, but for at least 8 bar of compression. I'm looking for the right materials. The design will be exactly the same because it works very well, and I will add the bolt-type diabolo carcass system. It will be a first attempt to do something fairly "definitive", (until the next idea)

[jackssmirkingrevenge]

Unfortunate incident that cost me a scolding as if I were a silly child .... really yes! I was !! When he came from the street, he saw by magic and that kind of radar that women have to know about "other women" and strange holes in the doors. I "shot" with a penetrating 50 gauge look

Ah, marital bliss... on the other hand, women love a man with passion

The weapon is missing the bolt system to introduce the ammunition. I am working on it. The screw system is quite uncomfortable.

It definitely deserves a repeating feed!

It would be interesting to make one of a larger caliber ... you say use steel balls? or lead ammunition? The problem in my case is the noise ... I'm tempted to do something bigger. I'll see if I can build it with a big silencer.

Rifled barrel with lead pellets is a good solution for long range, but it depends on the sort of performance you're getting. Diablo type pellets tend to destabilize near the speed of sound, so those with high powered airguns tend to go for "bullet" type projectiles like these. Do you still not have a chrono? If so I am still willing to donate one to the cause.

Ultimately, what do you want to do with it? If it's target shooting at longer ranges, then you're on the right track. If destruction at shorter ranges is the goal, then something like 3/8" ball bearings would probably be a more interesting choice. Being less dense, steel will accelerate more than lead and being harder it will penetrate better.

A larger (say 0.5"-0.7") smoothbore barrel - assuming you could bore out the chamber entry to match it - would give you the possibility to make a small shotgun which again would be good for breaking things at short range.

Regarding the noise, since the pressure from hybrids is largely generated by heat, the same principles as a firearm suppressor apply so there are a lot of designs out there.

Alternatively, for the ultimate in noise abatement, you might want to consider a Captive Piston that traps all the gas, but that is a considerable engineering challenge especially with limited tooling and the rate of fire would not be exceptional - thought since you have to pump it up, maybe the latter point is not an important consideration.

What interests me also, is to compress at higher pressures, as I said in the previous post about 8X, because I am with 4.5 - 5X one gets used to this and it is "necessary" more. In spite of this, it surpasses a 5.5-speed spring gun, not a "super rifle" but it is a factory made weapon and heavier and much more backward than this hybrid. Not to mention the price difference .... Mine weight 2.5 kg. I'm going to build it completely again, but for at least 8 bar of compression. I'm looking for the right materials. The design will be exactly the same because it works very well, and I will add the bolt-type diabolo carcass system. It will be a first attempt to do something fairly "definitive", (until the next idea)

You can never have enough power If you stick with a small caliber, then upping the pressure is the way to go.

[hectmarr]

Actually I'm interested in using common diabolos and steel balls that are not too big. I'm going to raise the firing pressure a little more. The objective is to make a weapon just like the common rifles that are bought, but hybrid.
As for the power, I do not need something very powerful and dangerous. I experimented with cartridges .22 of the nail machine, (the red ones), and shoots 5.5 mm bullets with a rudimentary but robust system, in a very powerful way and it is very simple to do. I have left it because it is VERY dangerous to play ... shoot more energy than my fire caliber revolver .22. I do not think it is very prudent to spend 8 or 10X. This way I can shoot in the backyard, or in the field with children and friends who know nothing about weapons.

I had no idea that this type of ammunition existed ... and the problems of the diabolos in speeds that tone the sound. I calculate that this weapon is around 800 fps when compared with other commercial spring weapons that claim 700fps and that with the same 5,5 mm diabolos, they drill a little less than my hybrid. We have checked this with my friend, here in my house.

I do not have a chronometer yet ... if you have one to sell at a very low cost, I buy it from you. It will definitely be useful to quickly compare the different design variants. We communicate through messages scheduled for this topic. :bounce:

[mobile chernobyl]

... It's a shame this forum is not as active as it used to be because a self-contained hybrid was a bit of a holy grail for many members.
...

I'm still watching the forum from time to time haha

[hectmarr]

In general the forums of any topic have decayed enough. I imagine that social networks are one of the causes. I see several forums, music, technology etc and I see the same constant. It will be necessary to take the forums to the same social networks maybe, I do not know.

[farcticox1]

Lots of airgun related groups on Facebook,

[jackssmirkingrevenge]

I'm still watching the forum from time to time haha

Glad to hear it

In general the forums of any topic have decayed enough. I imagine that social networks are one of the causes. I see several forums, music, technology etc and I see the same constant. It will be necessary to take the forums to the same social networks maybe, I do not know.

It's hard to evaluate. Certainly there are a lot of kids still interested in making things, but I think the Pareto Principle applies as it always did, it's a relatively small minority generating the majority of builds. Social media is definitely a huge distraction, reddit for example is my personal weakness and I have to consciously stay away from it because it's easy to get lost for a few hours clicking through links and *poof*, there goes your free time. There's also the dopamine high of getting meaningless karma for ultimately just reposting someone else's picture or video - if you get that kind of satisfaction easily, you're going to be less inclined to actually build something meaningful.

With this forum in particular, it seems like it was a hobby of a generation that petered out as that generation slowly grew up - education, marriage, children, those black holes of time and money that keep you away from high velocity produce.

[hectmarr]

I definitely do not use social networks because as Jack says it's a big waste of time. In the face I saw some basic groups on these issues, but there is no forum in itself, there are no discussions.
You have to make many weapons, because this field is long and short life

[jackssmirkingrevenge]

You have to make many weapons, because this field is long and short life

Words to live by!

[hectmarr]

I start moving with the HA II-2, (Autonomous Hybrid 2, second version).
It is basically the same as this post but 9X-12X. The two types of steel cord springs, three of each, came to me to make it. They are made to measure according to what I have calculated that I need. One type has 29 mm outside and 4.5 mm wire, and the other 26 mm outside, with 4 mm wire. With this I will be able to retain the design pressures in the combustion chamber.
I expect a 32mm steel tube inside and about 3.5 mm thick wall that should arrive these days. It is a tube that supports 300 bar, with burnished interior, of those used for hydraulic high pressure cylinders. The bad thing is that the whole project is slower, because everything does not depend on me.
Well I leave a picture of the springs and planes with the forces and lengths.
It will have the new weapon, a bolt system to recharge the ammunition, and an open sight, which I already have fiber optics. The air pump will be with other design values, and the caliber will be .22. I already have a new firing gun of 58 cm.
The new combustion chamber will have a car spark plug, and it will be adjustable, in terms of its size. It can go from 15 to 35 ml.
The peak pressure point can also be regulated. This is important because it allows me to adjust the peak pressure and volume necessary. I will upload the diagram of the combustion chamber and how these two issues are regulated.The project has not died, I am gathering the necessary materials to improve it.

Edited: A couple of hours ago I got the steel tubes. Very cute ! :bounce:

[hectmarr]

This is the design of the adjustable combustion chamber, for the HA II-2.
To regulate the volume, more or less washer capacity is used. More washers, smaller volume and fewer washers, larger volume. This affects the assembly of the front cover, piston, spring and back cover,(Gray and orange color).
To regulate the moment in which the exhaust hole "E" is opened, the distribution of the washers is varied (without varying the quantity of them). More quantity in the front cover, it opens faster, because it approaches the exhaust hole "E", which is fixed, and conversely, it opens later. With this it is possible to synchronize, by means of tests, that the hole "E" opens very close to the peak of maximum pressure.
Actually the resistance of the ammunition to travel the firing tube, acts in coordination with the point of opening of the exhaust hole. I have done many tests at the same mixing pressure, same shot gun and same ammunition, with this system and with another system, which uses rupture discs, and there are no differences in terms of the effects on the same type of target. The advantages are clear. It does not use rupture discs or it can regulate important aspects without remaking anything.
I leave the diagram for clarity. regards

[keks2033]

I think, on temperature and dirt rubber seals quickly deteriorate

[keks2033]

You can do so. On the red piston, too, there are rubber seals that would be tight. The area of the red piston is small, so there is no need for a strong spring. The green piston can be made without a spring so that it can open the gas outlet completely. A bit difficult, but I'm sure you get the idea.