Using air rifle technology to produce a marker that compresses it's own air...

[Styles]

While tech chatting with a friend he brought up an odd theory for a paintball marker design. One that doesn't need a tank to fire paintballs. His idea was to use compression pistons to take ambient air and compress it to fire the gun. Using possibly two against each other, powered by rams, and one of these rams possibly linked to the bolt. Then you would simply need an air source to power the pneumatics, which you'd think a 45/45 system would give an enormous amount of shots.

Obviously, you'd run into a lot of problems, like how to get air into what would need to be a sealed compression chamber, closing it off so it doesn't vent to the ball when being compressed, velocity control, etc. I don't know what sort of mechanical requirements would be needed to create the pressure needed to fire a ball from nothing, but many air rifles can fire heavy lead pellets at quite high velocity with one cocking stroke, although a lot use a spring.

Just something I thought i'd throw out, it would definitely be a neat idea if it could be implemented.

[SeeK]

If I understand this correctly you would use the HPA to power a small piston that is linked to a larger piston to move ambient air. This would be the reverse of an air compressor. It would also be a reverse Genisis. The compression (or decompresion) ratio would need to be 8:1 to create 100psi air from 800 input.

[Styles]

Yes your air system would only run the pneumatics.

The idea was brought up of having two pistons that work against each other, theorizing that two compressing air into one space would require less force than one. I do not know if this is physically true however, all this stuff would have to be worked out.

Here is one crude sketch of that basic premise:

[SlartyBartFast]

From what I understand the idea is impossible. You can't summon energy from nowhere.
The air energy fed to the pistons would have to equal the air energy required to fire the paintball.
In fact, due to energy loss and inefficiencies, more air would be required than if the compressed air from the tank were used to directly propel the paintball.

[toymyster]

Slarty said it!! You are looking at a prepetual motion machine, which is physicaly imposible to create!!!

[flanders]

wel battery...but it would be a juice hog

or pump

[speedyejl]

mabey a system more like in an airsoft AEG would work better.

The way it works is like this, the paintball falls in the breech, you pull the trigger, the motor pushes the piston back on the spring, then releases causing the piston to preasureize the air infront of it which hits the paintball.
The drawing is very rough but it gets the point accross.

Just to note a paintball weighs 12x as much as an airsoft bb, and its diameter is 30x larger.

[ScatterPlot]

I am Bert, summoner of Energy. Hear me Roar!

[SeeK]

http://www.carltech.com/aircraft/com_emerg.html

This may be more in line with the original idea. Sort of like a water aerator that makes the water pressure seem higher.

[SlartyBartFast]

Originally posted by SeeK
This may be more in line with the original idea. Sort of like a water aerator that makes the water pressure seem higher.

It may be in line with the original idea but it has no application in Paintball. The aspirator is used to create more air volume not more pressure. It's a venturi effect device, like a carburator.

The same type of device is used for water pumping for sump pumps as well.

I beleive the operation of such devices depends on the pressure drop over the length of the device (pressured input, non-presurised output).

Would be interessting however if a smaller amount of 1000psi air than currently required could be used to provide the cubic inch of 400 psi air required to fire the automag.

[Vendetta]

I would be interesting to have a pump paintball gun. How many pumps would it take to get a .68 caliber ball to 280fps?

[Conqueror]

IIRC, Punisher did it. He said it took over 40 pumps to get 280.

CQ

[Styles]

Originally posted by toymyster
Slarty said it!! You are looking at a prepetual motion machine, which is physicaly imposible to create!!!

No, not exactly. This would still need an external power source, a tank. The tank would run the operating system instead of providing air for propulsion.

I had thought about the airsoft setup, but would require a pretty beefy motor and power it seems. If you could do something similar with pneumatics instead, maybe it would be possible.

[Vendetta]

Translation please. My Elvish is a bit rusty

[mykroft]

Styles,

You are trying to violate the 2nd Law of Thermodynamics. You get energy loss whenever converting from one type to another, and your system adds a conversion. While it might work, you would lose efficiency over the current system rather than gain it.