low pressure mag style

[SteelSoul]

Oh ps

I have been shooting with a lapco for 5 years now.
Shoots darts and just is a nice barrell

and Slarty your at 2000 posts

[SlartyBartFast]

Sorry Steelsoul, but you don't have the understanding of the Mag's operation right.

Watch one of the available animations for a while.......

There is absolutely nothing a secondary regulator could do to help.

The dump chamber is completely isolated from the regulated supply before the bolt is released.

But, once released, the bolt remains open until the pressure in the barrel equalises with the pressure in the chamber. That means the cahmber is still dropping in pressure after it's useful.

What you want to do, or at least what I'm discussing, is to cut off the delivery from the chamber to the barrel faster. That would actually result in higher residual pressures in the dump chamber.

[hitech]

You'll have to bear with me. This was created in word, which isn't a CAD program by any stretch of the imagination. Basically, the existing power piston would be two pieces. The larger part (the second stage that is attached to the bolt) would have the existing hole drilled all the way through. It would need to be a "stepped" hole (not shown) to provide a stop for the other part. The smaller diameter part (the first stage) would extend into the hole that is drilled all the way through. The ovals are a spring that ends at a threaded (and adjustable) setscrew.

The drawing is shown in the pressurized and "retracted" state. When the bolt moves forward and the pressure against the smaller power piston drops the spring would extend the smaller power piston and reseal it against oring in the carrier. The bolt spring would later return the bolt. Once the dump chamber pressure builds the smaller power piston would "retract" and be ready for another firing cycle.

[Jakedubbleya]

But, once released, the bolt remains open until the pressure in the barrel equalises with the pressure in the chamber. That means the chamber is still dropping in pressure after it's useful.

What you want to do, or at least what I'm discussing, is to cut off the delivery from the chamber to the barrel faster. That would actually result in higher residual pressures in the dump chamber.

first par: Is the ball leaving the barrel before the chamber equalizes then?

second par: And faster cycling speeds

Hitech, id give you a comment or two but im still trying to figure out your whole idea...

[SlartyBartFast]

first par: Is the ball leaving the barrel before the chamber equalizes then?

second par: And faster cycling speeds

Hitech, id give you a comment or two but im still trying to figure out your whole idea...

First: Yes.
Second: Yes.

Hitech: I haven't figured it out yet.

[hitech]

Sorry for the crappy drawing, but I'm a software engineer, not a mechanical engineer.

Basically the existing power piston in the level ten bolt would be split into two pieces at the existing "step". The smaller diameter piston would slide inside the larger diameter piston that would remain attached to the bolt. When fired everything would initially work like it does not. Instead of the entire bolt returning to sear the dump chamber the smaller diameter power piston would extend from the larger power piston and reseal the dump chamber before the bolt returns.

That make any more sense????

This would be the "extended" stage that should seal against the oring in the carrier:

[SlartyBartFast]

That make any more sense????

Sure does.

First thoughts: It would be interesting to test this arrangement. The interaction of all the various springs and pressures may be VERY complex.
But, if the initial burst lowers the chamber pressure sufficiently so the lvl10 can't open, it may well close the chambrer faster. Unfortunately, the bolt still won't begin moving backward until the current pressure regulating/balancing action takes place. Unless the 'moving' lvl10 section can actually shut off the air flow with the bolt in the forward position.

Hmm. Who's going to test this?

[hitech]

Yes, the problem is that I don't know most of the details. The spring strength is obviously the big variable. I would think starting light and progressively getting heavier and heavier until the velocity starts to drop would determine the low end of the required spring strength. Continue with heavier springs until the bolt no longer completely cycles would determine the high end of the spring strength. Pick the middle and allow for adjustment.

It might actually work. But you never know until you actually try it.

Unless the 'moving' lvl10 section can actually shut off the air flow with the bolt in the forward position.

Yes, that is the whole idea. If it can't it won't work.

[SlartyBartFast]

Hitech's version looks really worthy of prototyping. But, can you get a spring that small and can the extension be made long enough?

For my initial approach (that is regulating the air delivery and not changing the bolt, I was thinking along the lines of a Flow Limit Shut-Off Valve such as this:

http://www.scottecatalog.com/DSGuide.nsf/0/e2035370d7b9b9ea852568f2005d23af?OpenDocument

or

http://www.aquadevice.com/english/04valve_ufsd.htm

which could be built into the base of the power tube.

Or a mechanism similar to the following would be PERFECT.

http://www.oilfield.slb.com/media/services/coiled/tools/differentialvalve.pdf

Only glanced at the info so it's probably huge and terribly expensive.

What you want is a "snap action" regulator that would cut-off the output from the dump chamber based on an adjustable differential between the regulated input from the A.I.R. and the dump chamber. Then you could accurately set the high and low pressures for the dump chamber.

After that, the next big gain in cycle speed would come from the system automatically resetting and recharging the dump chamber without the need to release the trigger.

Need any R&D employees AGD?

[hitech]

Thanks, but it's not my idea. I just tried to explain it.

I wonder if you could make the power piston like a spring with a plunger on the end? So when it's all gassed up and all, the spring is compressed, and the piston's normal length, then when it fires the piston extends a little and shuts off flow quicker.

[athomas]

I don't see the bolt stem spring idea working. At first I liked the idea. Then as I thought about it, I don't think it would work. Under normal chamber pressure the stem would be compressed and function as we know now. When the bolt blows forward the gas is released until the chamber pressure is reduced enough to allow the stem spring to uncompress and provide a sealing action in the powertube to stop the flow. The problem I see, is if there is enough pressure to keep the bolt forward, it will also keep the bolt stem compressed. If you make the stem spring heavier than the bolt spring, then you run the risk of not having enough chamber pressure to compress it under normal operating conditions.

I have always liked the idea of altering the chamber size to achieve efficiency. Reduce the chamber size and decrease the time required to achieve the low pressure to allow the bolt to return. A reduced bolt forward time equals less wasted gas which translates into greater efficiency. You may have to increase the operating pressure just a bit. I think the amount pressure of increase would be very minimal, especially when compared to the increase in efficiency.

Different gun have different bolt designs. Each different design delivers different barrel length efficiencies depending on the rate at which the bolt releases gas. The most efficient guns will have a very open valve system and will have a very low internal chamber pressure. They will be able to release that gas almost instantaneously. Its the high impulse pressure and high acceleration that gives you efficiency in a painball gun. the mag bolt design does not lend itself to that design. So we need to compensate by operating at a higher pressure. A very efficient design will accelerate the ball in the shortest length.

[SlartyBartFast]

Under normal chamber pressure the stem would be compressed and function as we know now. When the bolt blows forward the gas is released until the chamber pressure is reduced enough to allow the stem spring to uncompress and provide a sealing action in the powertube to stop the flow. The problem I see, is if there is enough pressure to keep the bolt forward, it will also keep the bolt stem compressed.

Impossible. Or, you're explaioning your concern in the wrong way.

When enough pressure is released from the chamber to be below the lvl10 threashold, the lvl10 section will close the dump chamber and the remaining air will escape out of the bolt.

There may be a danger of a small amount of compressed air between the larger diameter of the bolt piston and the sealed lvl10 section. (is that what you mean?)

The return spring would need to be strong enough to overcome that to avoid "bolt stick".


We'll never know without testing....

[athomas]

When enough pressure is released from the chamber to be below the lvl10 threashold, the lvl10 section will close the dump chamber and the remaining air will escape out of the bolt.

We'll never know without testing....

I never said I might not be wrong. That is what testing proves.

However, the way I see it, the bolt spring is always exerting pressure on the bolt to force it back. As soon as the chamber pressure is released such that the force is below that of the bolt spring, the bolt starts its return. The weakest spring (proportionally) will be held forward the longest time. For the stem to close the powertube before the bolt spring starts its return, it would have to be stronger than the bolt spring. The unfortunate downfall is that the chamber pressure to fire the gun vs the bolt spring is so critical to maintain antichop, that various various chamber pressures due to velocity-bolt setup could prevent the system from functioning properly.

[hitech]

Remember that the bolt it being held forward by pressure against the "large" piston. The "smaller" piston produces much less force. We know this based on the way the level 10 works.

[paintballbeaver]

a gun that works almost exclusivly like the automag and functions nearly the ame is the desert fox..

the gun is the base for the icd freestyle

the freestyle is esentually a pnuematicly controlled mad it vents air pressure to fire the gun and sends it back in to stop it..

like the spring in an automag