Filled Level10 bolt to improve efficiency?

[LoveMyMagMoreThanYou]

So, can anyone tell me how two guns with the same size dump chamber, equal pressure but two different bolts with the dimensions previously mentioned use two different amounts of gas? I think that the Level 7 bolt is more efficient than the Level 10 because of the insane pressure that you have to turn the reg up to in order for the Level 10 to work. If you change the pressure in the dump chamber, then you use more or less gas, depending on if you turn the pressure up or down.

[the electrician]

yeah....I know how the lvl10 works dayspring. but you don't need to discharge much air to get the bolt to stop and reset. it definitely doesn't need to leak out the back of the bolt either.

do you think that the extra "hollowed out" area is essential to the lvl 10 operation?

[athomas]

The hollowed area contributes to the weight reduction. If you fill this area, you will increase the mass of the bolt. If you increase the mass, then you also increase the amount of energy required to move it. The moving momentum of the heavier bolt will result in more impact power when hitting a ball, which will result in more breaks and chops.

The bolt design may be able to be changed though. Perhaps less can be milled out of the inside but more milled off the outside. Leave the tip large and the base near the sear catch large. Mill some of the area in between. Maybe this can't be done, due to instability of the bolt spring during compression. Too bad we couldn't find this out.

Figuring that the hollowed area causes a pressure drop might not have a huge factor in the equation. The pressure that reaches the ball never goes above 60psi anyway. Maybe the bolt volume acts like a volumizer and actually helps maintain constant pressure behind the ball. I doubt it but without data, who knows.

The inefficiencies of the level 10 are a result of the higher pressures and the higher spring tensions. The bolt stays forward longer because after the initial high impulse pressure of the chamber is released, the bolt spring acts like a regulator and lets some of the remaining air out slowly until the chamber pressure drops below the pressure required to maintain the bolt in a forward position. Then the bolt spring returns the bolt back to the reset position. The slower escaping air happens after the ball has left the barrel or at least after the ball is far enough down the barrel that any more air is not a factor. This air is wasted and contributes to the inefficiency.

If we are looking at ways to modify the bolt operation for better efficiency, the idea of eliminating preleakage during the bolt movement is probably not going to get us much gains. The gains will be realized only if we can get a high impulse pressure behind the ball after the bolt has reached its forward position and then terminate it quickly so that only that impulse pressure is used to power the ball. A high pressure, quick jab of air will do that. We have the high pressure now, but it doesn't shut off soon enough. How so we do that? Make the chamber smaller. The initial impulse will be the same, but it will trail off quicker resulting in less wastage.

[the electrician]

the hollowed out part of the bolt doesn't save that much weight compared to the total weight of the bolt. I don't know if it is actually needed or not.

the real reason you can't mill off the outer part of the bolt is because of the next paint ball in line would want to fill the void created. not good. you're almost always better off taking mass out from the inside of a bolt.that's just my opinion.

well I'm using my original spring with my lvl 10 bolt and it still uses more air. so I don't think it has anything to do with the spring. as far as the inefficiency of the lvl 10 goes.

I like the idea of the quick. high impulse pressure behind the ball. I'v found that stock cocker bolts work better when you bore the face of them out, and enlarge the charge hole a bit. perhaps this could be applied somewhat to the mag? a higher flowing bolt wouldn't slow down that initial blast of air as much.

I think you're right about that being the high point of wasted air in the design.

I don't really like the idea of a smaller dump chamber. it's already running on high enough pressure, and I believe that a smaller chamber would just run on more pressure and without increasing flow (orfice size) in the bolt, the higher pressure air will not flow faster. I don't think it would be anymore efficient. I don't really know. just my opinion.

I can see that I'm going to have to set up some tests, and perhaps make a few pieces. see what helps and what doesn't.

[the electrician]

man....I just realized why the lvl 10 needs more air pressure to operate than a standard bolt.

go to the very beginning of the power tube. right in front of the dump chamber. the first thing you put in is the little white washer, then the carrier. look how small the gas path is through the carrier compared to the old bolt. it's a lot smaller. so you need more pressure just to get air to travel close to the same velocity it was before through thenow smaller orfice, to get the same amount of energy to the ball.

so no matter what you do to the rest of the set up, it will never be as efficient as the old bolt.

It's a trade-off. a gain of no chops for a loss of some efficiency. when you think about it, it's a good trade.

it wouldn't hurt to try and eliminate the back of the bolt leakage, and try to eliminate blowback up the feed tube, but it probably won't help to awful much either.

I'l bet somebody at AGD has already played with eliminating wasted air in these places. makes me wonder what the conclusions possibly were.

[athomas]

the real reason you can't mill off the outer part of the bolt is because of the next paint ball in line would want to fill the void created. not good.

I forgot about that part. :o


A higher pressure will always make up for a restricted flow path. We do have a restricted flow path in the present bolt design. Therefore, it makes sense to increase the operating pressure. Its a hard one to argue in the low pressure world though.

I wonder if we used a larger powertube (same design) and consequently a stiffer bolt spring. The bolt stem would have to be larger, but it seems that the volume is there. The opening wouldn't have to be that much larger to allow considerably more air flow. More air flow would mean the high sustained impulse pressure but would terminate more quickly.

[hitech]

The gains will be realized only if we can get a high impulse pressure behind the ball after the bolt has reached its forward position and then terminate it quickly so that only that impulse pressure is used to power the ball.

YES, that is the way to go. That will yield the biggest gains in efficiency. The problem, how to do it? A bigger power tube and power piston coupled with a stronger spring sound like a good idea. The only problem is making it.

I still think that a smaller dump chamber would work also. It won't get a higher impulse pressure behind the paintball, but it should cut down on the waste after the paintball is gone. It's also the easiest to try.

[the electrician]

it's all good Athomas, we've all done that.

I dis agree with the higher pressure always making up for a restricted flow path though. there is a certain point where flow is somewhat regulated by the orfice. that is how flow controls work. if the orfice is small enough, higher pressure just won't go any faster after peak velocity for the particular orfice is reached. now I don't know about the lvl 10 carrier flow orfice. at what pressure does this orfice reach maximum air velocity? probably alot higher than what we are going to need.

hitech, if it's easier to make the dump chamber smaller, how do you plan to do it?

I'm not into trying a larger power tube and stiffer spring. higher forces, higher pressures, higher opposing forces. seems the wrong direction.

I'm afraid I'm with rrfireblade. time to design a new gun altogether.

[hitech]

hitech, if it's easier to make the dump chamber smaller, how do you plan to do it?

Just fill the existing one with something. A short length of ss cable "wound" in so that it uncoils once in the chamber and stays put is what Tom suggested.

If you can find an old level 6 classic valve and remove the power tube (boiling the valve in water loosens the loc-tite) it would be even easier.

I would try it. However, with just moving and the wife due June 15, I don't have any spare time.

However, you are right, the design is old. It really needs to be redesigned. It does have its advantages; efficiency just isn't one of them.

[the electrician]

man I'm not brave enough to put anything in there I couldn't get back out. :)

I'm not really into trying higher operating pressures anyway. mine already operates on 500 psi with the level 10.

I really just want to make it a bit more efficient to increase the recharge rate. if you can decrease the operating psi through efficiency increase(not a larger damn dump chamber) then you decrease needed recharge time.

how come my cocker operates on 200 psi and can rattle off 20 bps consistently without drop off? it recharges quickly. the difference between tank output(800 psi) and operating psi(200) is 600 psi.
in my mag the difference is only 300 psi. I think there needs to be more of a difference there.

if you use an adjustable tank, you could bump the output up to 1100 psi, and that would probably help. I don't know for sure.

I've got the classic valve running at 18 bps.
I think it could do more.
that's with a homemade electro set-up, and some on/off modifications
it has a solenoid pulse time of 30 msec, so that leaves about 26 msec for recharge, minus whatever msec for a bit of reaction time.

with a few more mods, I think the classic valve could do 20+ bps with the lvl 10 bolt.

you could get consistent velocity, high rof, and keep up with other guns no problem. the classic valve could be used with Nicads hAir trigger.

but that's just kinda my own personal agenda, and interest in this thread.

[LoveMyMagMoreThanYou]

The Autococker uses a complex series of pneumatic mechanisms to cycle the bolt and only uses the air in the dump chamber for propelling the ball. The Mag uses the air in the dump chamber for both. I think the solution is to use a spring to help push the bolt forward and return it. I don't know if that's possible in the Mag but it would solve the problem of using the dump chamber for double duty.

[athomas]

I dis agree with the higher pressure always making up for a restricted flow path though. there is a certain point where flow is somewhat regulated by the orfice. that is how flow controls work. if the orfice is small enough, higher pressure just won't go any faster after peak velocity for the particular orfice is reached.

Higher pressure doesn't always make a difference, but that's only when the maximum throughput of the orfice is reached. We are nowhere near that flow rate. That is why we can adjust the velocity by adjusting the chamber pressure. Since we can't change the diameter of our orfice, we have to increase flow rate by increasing the pressure. If we want a higher impulse pressure we need more pressure. But more pressure in our present setup means higher velocity. So, like mentioned before, we need to make the chamber smaller.


How hard is it to get the powertube off the front of an air valve? I think if it is only loctited on, it should be easy to get off with some heat. Then, let the experimenting begin.

[the electrician]

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I dis agree with the higher pressure always making up for a restricted flow path though. there is a certain point where flow is somewhat regulated by the orfice. that is how flow controls work. if the orfice is small enough, higher pressure just won't go any faster after peak velocity for the particular orfice is reached. now I don't know about the lvl 10 carrier flow orfice. at what pressure does this orfice reach maximum air velocity? probably alot higher than what we are going to need.

man if you're going to quote me quote the whole thing brother :) kinda made me feel like we were running for office against each other. LOL

I agree with you, probably won't be a factor, but nobody knows because nobody seems to be interested in going through with trying to make the dump chamber smaller.

I don't want to go that direction, more pressure means more force. I'm more interested in reducing pressures and forces.

I might try the original idea of this thread. see if it does anything. perhaps turn a piece of delrin to slip in the bolt.

I really would like to do something about the blowback up the feed tube. but I'm not sure what. bolt o-ring? that won't last very long. a breech o-ring? I believe smart parts is using that and calling it "seal forward technology". technology? it's an o-ring for pete's sake, not very hi-tech. does it work? I don't know. but I have to say it is interesting.

[athomas]

Sorry if it sounded like I was questioning you. I only quoted that section to highlight the area I was commenting on. :)

Is the blowback of a level 10 bolt really an issue? Mine is hardly noticable. Now on the level 7 bolt it is noticable.

Blowback occured in the level 7 while the ball was in the barrel. In the level 7 setup, the bolt returned more quickly. It was once stated that the ball was quite often still in the barrel when this happened. Therefore, the higher pressure resulted in some of the pressure being released up the feed tube.

In the level 10 setup, the bolt stays forward longer. The ball leaves the barrel or is near the end before the bolt returns. The air pressure goes out the barrel. While this results in wasted air, it does help prevent blowback. On a level 10, the blowback is only what escapes around the bolt tip. The amount escaping out the back has to go around the back of the bolt, through the compressed spring, and into the feedtube between the bolt and breach wall. Some of it will go out through the rail by the sear assembly and some will go out the back past the valve as well.

Ok, now we need someone to mill a groove at the end of a bolt tip. You could use different sized o-rings depending on barrel id. Maybe the o-ring doesn't have to seal, just tighten the tolerences. The o-ring should be far enough forward so it won't be affected (chewed up) by the bolt spring.

[hitech]

man I'm not brave enough to put anything in there I couldn't get back out. :)

I'm not really into trying higher operating pressures anyway. mine already operates on 500 psi with the level 10.

I really just want to make it a bit more efficient to increase the recharge rate.