Single pumping hybrid, "Strong Boy"

[hectmarr]

I am building this charger to provide future "Strong Boy´s" mono pumping, with a very simple system of loading 1/4 "bb's.
The idea is not to complicate the weapon, I want it very simple, but avoid loading the ammunition through the firing cannon with the drumstick. It is what does not conform me much.
It has a Li-Po battery, 7.4 vol, and 850 milliamps, very small, and a key to actuate the solenoid that has a power of about 70 - 80 W. I have used bronze for the tube where the core moves mobile that seals the charger and also opens it. The tube carries bb´s, is copper, and the only thing of steel, is the mobile core. This small cylinder has a 5 mm hole in the center, which is where the gases pass to the cannon, during the explosion. The spring is for the mobile nucleus to return and accommodate, (making a certain force due to the same spring), the ammunition in the retention o'ring.
I will take some pictures when I do the test experiment.

[hectmarr]

Successful test run! The simple charger works perfectly, makes a metallic sound barely perceptible and most importantly, does not fail.
I have charged about 200 bb´s and the small battery seems to still have a lot of charge. The idea is that in the real weapon, the tube that houses the bb's, is below the barrel and parallel to it. For the tests, I have installed a small and very soft spring, so that it works against gravity. When I have time, I will make a video of the test.
This test weapon is the first one I built, and I am using it to test ideas. I leave a picture of the experiment.

[jackssmirkingrevenge]

Great idea! This way you are not limited to spherical projectiles...

I had tried to make something similar a long time ago where a solenoid pushes a bolt forward simultaneously chambering the projectile while opening a balanced valve but sadly both my materials availability and electronics knowledge failed me. Perhaps it would be worth revisiting now.

Of course you made it work effortlessly, looking forward to the video!

[hectmarr]

Hi Jack! Nice to see you here.
I saw your drawing and it's good. I think the solution, for your specific case and the power of the solenoid. Many amps will be necessary to overcome the resistance of the o´ring, and little more than that. According to what I have tried, with about 800 w, it would be enough to move your idea.
In my case, all this simple mechanism is inside the combustion chamber, so it has no o´ring, and works with about 7 volts and about 10 amps.
I have not tried using non-spherical ammunition, (because I am designing this exclusively for mono bombeo "throws balls"), but I think it can be adapted without much work, to use pellets.
I comment that the mobile core that seals and opens the tube where the bb's are housed, is responsible for only one bb entering. When the solenoid is activated, it attracts and sticks in it, the bb that has already entered, leaves no place for the next one to enter. Operating the mechanism with the hand, when it opens, 2 or 3 bb's enter, otherwise, when it is activated with electric power, only 1 bb enters, always.
The tube where the bb's are housed, is pressurized and is part of the combustion chamber, because it is the only way to avoid the o´ring, which would require a powerful solenoid, and therefore, a battery and a winding more big, which is not a friend of a small gun.
Lo probé y no es un problema. Cada bb de 1/4" tiene un volumen de 0,14 cm3, y cada una que disparas aumenta el volumen de la cámara de combustión en esa medida. No he apreciado diferencias de ningún tipo, al realizar los disparos, con en tubo de municiones lleno o con solo 1 bb.
Ya subiré el video, pero no es algo espectacular, porque casi no sabes cuando se ha cargado el bb.

[hectmarr]

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[jackssmirkingrevenge]

Here a video of the operation.

Wow, the muzzle velocity is much lower than I expected



Looks great, very inspring! An electro-pneumatic repeater will definitely be on the cards once I get my workshop sorted.

[hectmarr]

Actually the solenoid's mobile core only lets out one at a time, and supports the ball in the center of the retention o'ring. The important thing is to give the position in the center and not move. When compression begins, the air is strong and nails the bb.

[hectmarr]

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[hectmarr]

Upgrading the single-pump gun. I'm trying to build the drawing. It has associated to what is in the drawing, a loading system for 6.35 mm bb's to make it a repetition weapon
I'm working on a rough prototype to test the concept. The goal is for it to shoot and function the way I want it to. I'll upload some photos when I can.

[hectmarr]

Here some photos of the "monster" that works very well! It is unfortunate that it only compresses at 3 bar because the compression cylinder that I used has an internal diameter of 26 mm, which is a lot to generate without any lever, more pressure. What's nice is that you can shoot on repeat and it promises long hours of shooting fun at targets like beer cans, cardboard boxes etc. It is very quiet, because the air is just right, the barrel is a bit long and the pre-compression pressure is low. In the future I will try a long gun with this system, but with a tube no larger than 18 to 20 mm and built more neatly. This was just to see if it works and where the weaknesses are in the overall system to modify the design before spending money on machining parts and materials.
I will make a video to share here.

[jackssmirkingrevenge]

Fantastic job, look forward to the video

[hectmarr]

Híbrido MB largo, diseño final..png (7.34 KiB) Viewed 26461 times

Hibrido monobombeo 2, secuencia de operación.png (19.76 KiB) Viewed 26461 times

Here, chewing on a single-pump hybrid weapon, but this time, long, to fire pellets.
It would be necessary to use considerable force, about 45 to 50 kg to compress this device. Of course, I have to use my body weight, and the weapon resting on the ground. I would have a device at the tip of the barrel, so that it does not hurt itself against the ground.
Otherwise, the .22 pellet is associated with the rupture disk, and the system is as in the drawing.
The compression pressure of the mixture, (air and butane), is 10X. The dispenser is of the manometric type, in this case, and for a change, since the butane must be injected into the explosion chamber, before compressing the device.

[hectmarr]

I am including a couple of simulations made by Jack, on this weapon. In one case, the combustion chamber works with 180 cm3 of air and in the other, with 150 cm3 of air.

[hectmarr]

The video I owe around here, of the single pump pistol. In this case, they shoot 1/4" steel bb^s. I have currently switched ammo to 0.23 gram airsoft pellets ; It has about 3.5X and the performance is very good.

The operation of the gun in the video is very similar to the future long gun, except that in this case, the gun is simpler, because it does not have an independent compression piston, because the ball is introduced into the chamber directly.

[jackssmirkingrevenge]

Great stuff, it never ceases to please me to see your repeaters functioning so well! I look forward to the new project