Can I track the amount of air coming out of my barrel? TK? Engineers? Smart Peopl?

[MANN]

Alright I have an idea. I am wanting to see what kind of pressure the ball is actually seeing. The only way to do this would be to have a pressure gague where the ball sits. A detent would work perfectly. If I took the ball out of a stock agd detent, tapped it for a fitting, and hooked it up to a digital pressure reading device (which I have access to) this should work right?

The reason I am tring to do this is to go along with my barrel test. The velocity of a marker has to be adjusted for different barrels. I am wanting to see if there is any relationship between accuracy, and the pressure exerted on a ball.

My xmag has dual detents on the vert breech so I could always just use one while leaving the other for a detent.

I know that this would all hinge upon the idea that the automag is a closed system. Ie that there is no air loss in the removable breech, behind the bolt (thru the body), etc. But in theory this would work right?

[Pneumagger]

you'd need a pressure transducer. it would happen on a gauge, you either wouldn't notice or it wouldn't register.

The cheapest economy grade (only .1% accurate) transducers i could find were like $125 online. And you'd still need a data acquisition system for it as well. It's probably easier to calculate what the on-ball pressure should be given the dump chamber pressure.

[MANN]

I have access to what we call a TOY. I guess in reality it would be an electronic manometer. It is used to track the pressure in different processes. I will have to check on what the maximum pressure allowance is, but I think it would work. It has 0-10Vdc output so I will be able to hook it up to a datalogger. Ill try to find a link. They are @ 200.00 for a cheap one

[MANN]

It is similar to this

http://testproducts.com/safecart/pro...e09487eba71878

Like I said earlier I am not sure what the min/max pressure rating is. I am wanting to say ours is @ 500psi.

[MANN]

I am wanting to do this because I have no way to know the pressure in the dump chamber

EDIT **Now that I think about it the detent is probally "sealed" by the bolt when the marker is fired. Oh well another idea that wasnt thought through all the way.

[Chronobreak]

I am wanting to do this because I have no way to know the pressure in the dump chamber

are you needing an exact amount? i believe its around 65 psi at 280 fps

anyone cofirm that?, its probly in the tech files somewhere

[MANN]

are you needing an exact amount? i believe its around 65 psi at 280 fps

anyone cofirm that?, its probly in the tech files somewhere

What barrel/paint was used to get the 280
I am wanting to track it more than know an exact amount.

[wjr]

I think I might have a better way to find the pressure with out having to cut or drill anything. You could have an endcap made that would replace the regulator on the back of the valve. Then, you could use a standard inline reg with a guage in place of it. This way, of course, you'd see how much what pressure is needed to fire the gun at whatever desired velocity.

[Dark Side]

Alright I have an idea. I am wanting to see what kind of pressure the ball is actually seeing. The only way to do this would be to have a pressure gague where the ball sits. A detent would work perfectly. If I took the ball out of a stock agd detent, tapped it for a fitting, and hooked it up to a digital pressure reading device (which I have access to) this should work right?

The reason I am tring to do this is to go along with my barrel test. The velocity of a marker has to be adjusted for different barrels. I am wanting to see if there is any relationship between accuracy, and the pressure exerted on a ball.

Yes. Take a look at what happens when you increase your velocity. More velocity= more pressure on the ball= greater accuracy.

I'd take an old cocker barrel. Tap a hole 2 inches or so beyond the bolt. Hook up your lines and TOY. Put a barrel condom on and pull the trigger(with no paint). The condom should help the pressure not to dissapate too quickly there by giving a decent reading on your TOY.

[MANN]

I think I might have a better way to find the pressure with out having to cut or drill anything. You could have an endcap made that would replace the regulator on the back of the valve. Then, you could use a standard inline reg with a guage in place of it. This way, of course, you'd see how much what pressure is needed to fire the gun at whatever desired velocity.

I think that would be a little harder than tapping a detent. Dont you?

[MANN]

Yes. Take a look at what happens when you increase your velocity. More velocity= more pressure on the ball= greater accuracy.

I'd take an old cocker barrel. Tap a hole 2 inches or so beyond the bolt. Hook up your lines and TOY. Put a barrel condom on and pull the trigger(with no paint). The condom should help the pressure not to dissapate too quickly there by giving a decent reading on your TOY.

I am wanting to see the pressure on every barrel tho.

[wjr]

I think that would be a little harder than tapping a detent. Dont you?

I don't know... are you okay with doing that on an xmag? I also thought it would work if you couldn't get the right equipment or something.

And BTW, there's a guy on MCB who made me said valve cap for $15, and finished it in about two days.

[Tao]

Alright I have an idea. I am wanting to see what kind of pressure the ball is actually seeing. The only way to do this would be to have a pressure gague where the ball sits. A detent would work perfectly. If I took the ball out of a stock agd detent, tapped it for a fitting, and hooked it up to a digital pressure reading device (which I have access to) this should work right?

The reason I am tring to do this is to go along with my barrel test. The velocity of a marker has to be adjusted for different barrels. I am wanting to see if there is any relationship between accuracy, and the pressure exerted on a ball.

My xmag has dual detents on the vert breech so I could always just use one while leaving the other for a detent.

I know that this would all hinge upon the idea that the automag is a closed system. Ie that there is no air loss in the removable breech, behind the bolt (thru the body), etc. But in theory this would work right?

as long as the velocity out of the barrel is the same from barrel to barrel the NET force on the ball should be the same on the axis down range...so thinking net force is better than pressure as pressure= force over area which would be a nightmare with calculus figuring out which way the pressure is pushing a sphere :P


Pressure behind the ball at any given time BEFORE the ball leaves the barrel is irrelivant asside from the concern of gas efficiency. When the ball is in the barrel , any pressure against the ball which tries to push it off the line drawn from the back of the barrel to the front of it, is counteracted by the barrel pushing back on the ball with equal and opposite pressure. at the point the ball leaves the barrel any pressure still escaping the barrel will come into play. The moral of this paragraph is any leakage from the gun, or resistance from ball detents doesn't matter WHEN the ball leaves the barrel at an identical velocity.

What you would need to measure is the pressure of the 'cloud' of air (if any) which may surround or engulf the ball as it is leaving the barrel. If the pressure is unequal then it will be moved slightly perpandicular to its intended axis of travel (left, right, up, down, or a combination of two). Barrel porting is intended to correct this problem so if it still exists with some barrels many will want to know You would need a high speed camera and a coloured gas to see this in action. WIth the high speed camera you can measure any distance deviated over time and deduce the undesired (net) force on that particular shot.

**remember force has a direction so the force down range is irelivant since you would be testing at a constant velocity, but you can calculate an average a paintball of a certain type may deviate from this particular down range axis with barrel ABC.

Now....the next thing to watch for is what the combination of the pressure behind the ball combined with barrel resistance have on the structural integrity of the ball :P Basically is the force of friction between the painball and the barrel (different barrels will have diferent coeficients of friction with the ball even when they are the same bore size) so great that the shell gives out a little to dimple the ball which would catch air and put a spin on it once it leaves the barrel? Well this is a whole nother can of worms that I no not even want to contemplate :P


To make a long story short: the pressure on the ball only makes it travel XXXfps since the barrel corrects its path. Only if the ball gets dimpled due to extreme pressure along the way (or the extreme pressure warps the barrel), or the porting of the barrel fails to even out the exaust arround the ball, will pressure have any effect. Either way measuring any of this in the gun its self is irrelevant since we are interested what the ball is doing on the way from our gun to the target and the NET affect of what happens in the gun is observable as soon as the ball leaves the barrel. I think you would be better off with a high speed camera and some measuring sticks.



Oh yeah there is spin too...the ball could come out sith a front, back or side (spiral) spin. If the paitball is simetrical (note I did not say a perfect sphere) this should not happen in barrel, but may be caused by excess venting of air on one side when it leaves the barrel. Again a high speed camera will help you on this. Just count on average what revolutions per second any given barrel gives to a paintball.

[MANN]

I don't know... are you okay with doing that on an xmag? I also thought it would work if you couldn't get the right equipment or something.

And BTW, there's a guy on MCB who made me said valve cap for $15, and finished it in about two days.

lol. I dont think we understand each other. I am talking about tapping a hole in the removable detent. I have a few to spare. It would not damage anything except the detent. They are ~ 10 bucks

[Pneumagger]

why the heck does it matter what pressure it takes to fire a ball a certain speed from each barrel

In the RL, you're just going to slap a barrel on the gun and chrono it to 300 FPS. use 1 kind of paint, use a large sample size of shots to create statistically significant data (and negate ball to ball differences), and have at it.