Filled Level10 bolt to improve efficiency?

[hitech]

[RRfireblade]

That's just one of , not necessarily the biggests.

[hitech]

That's just one of, not necessarily the biggest.

[WetPaint]

I also wonder about the large rear opening in the bolt. Is the diameter of the power tube tip large enough to prevent gas from escaping to the rear??

BTW: I was playing with a 03 Shocker in the store yesterday. I turned off the gas supply and kept firing while watching the bolt throught the feed tube. To the end, the bolt still cycled the full distance, but with decreasing speed.. At least, in it's design, chamber pressure has little effect on cycling the action.
In the Mags, from my reading here, having the gun function at all is a delicate balance of spring weight, gas pressure, shims, and the weather in Mozambique..

Also, has anyone figured the theoretical maximum number of balls that could be launched at 300 FPS from a tank of given capacity and pressure, assuming a perfect, frictionless barrel?

[RRfireblade]

IMO,the primary cause for a decrease in efficiency in the Mag valve is the "cork in the bottle" design in the first place.

The way the Mag valve discharges the air from the dump chamber in the first place is it's biggest problem.When cocked the bolt piston is in the dump chamber,for all practical purposes.As the bolt moves out,the internal pressure drops drastically as the bolt piston no longer displaces it's own volume in the chamber.To compensate for this,the internal chamber pressure must be far greater than required to fire a paintball.Add to that the pressure required to move the bolt and compress the bolt spring(L10 forces you to increases that to it's max level)and your now way over the mark for best efficency.

Filling in the bolt only adds mass to the equation in exchange for a very minor reduction in air volume,hardly worth the effort IMO.

Therefore.....

All you need to do is enlarge the dump chamber,actuate the bolt with pnuematics and have the chamber dumped by a mechanical/pnuematic valve instead of the "pop the cork" bolt method and your there.

[hitech]

I would have to disagree with your basic assumption that higher pressures are less efficient. I would claim that higher pressures are more efficient. Basically, the faster you can accelerate the paintball the more efficient it will be. This is because you have to fill the volume behind the paintball. The smaller that area is the more efficient.

In regards to filling the power tube, the amount of air required pales in comparison to the barrel (the area that must be filled as the paintball travels). Worse yet, once the paintball is gone there is nothing to stop the air from escaping out of the barrel. Since the ball is LONG gone before the bolt returns, HUGE amounts of air escape.

[the electrician]

.As the bolt moves out,the internal pressure drops drastically as the bolt piston no longer displaces it's own volume in the chamber.To compensate for this,the internal chamber pressure must be far greater than required to fire a paintball.Add to that the pressure required to move the bolt and compress the bolt spring (L10 forces you to increases that to it's max level)and your now way over the mark for best efficency.

if you figure operating psi at 500, the pressure drops 50 psi before the air comes out of the power tube. I figured it up just the other day. can't remember the exact numbers, but I came up with about 50 psi.

I'm using the same spring I was using with my standard bolt, yet with the level 10, I have to turn the pressure up about 50 more psi just to get the same velocity. why? the bolt is lighter and the spring is the same as before.
I'd like to hear some ideas on that.

[Dayspring]

I talked to Tom in Texas a while back about this. He said he could make the Mag more efficient by reducing the size of the dump chamber. He didn't like the idea of it b/c it would mean his gun is "high pressure" and people wouldn't buy it.

Also know, when dry-firing, you completely empty the dump chamber of air. When firing a paintball, you leave about ~50psi of air in the chamber.

[hitech]

Also know, when dry-firing, you completely empty the dump chamber of air. When firing a paintball, you leave about ~50psi of air in the chamber.

Is that true for level 10? I thought those numbers where for level 7 only. It was my understanding that the residual pressure for level 10 was much higher, even when dry firing.

[Dayspring]

I imagine that Tom quoted me the LX version of the #s. Most guns are being equipped with that now, why quote L7 stuff.

But you're right. I never asked, so who knows.

[RRfireblade]

I would have to disagree with your basic assumption that higher pressures are less efficient.

Your allowed to disagree.

But I'm not talking about higher pressures in general,I'm talking about higher than would normally be neccessary....higher.

I built a proto mag contraption (it never actually became a Mag so I won't call it that )years ago with a ram actuated bolt,greatly abbreviated bolt piston and a few other 'secrets' and I can tell you that between that and an entirely different on/off mechanism,you will see the greatest gains in efficiency and the ability to lower the operating pressures to under 200psi.

[Cristobal]

I also wonder about the large rear opening in the bolt. Is the diameter of the power tube tip large enough to prevent gas from escaping to the rear??

Now that is a very good point. I imagine that the difference in diameters is at least a couple thousands. I don't know how much air can get out of there during a firing cycle, but it has crossed my mind that in this case having a hollowed bolt might be an advantage.

If you put a soft "seal" at the end of the power tube, just wider than the pt tip, it would slide cleanly inside the hollowed out section of the bolt, but would seal against narrower back of the bolt when the bolt came all the way forward to fire. It might be as simple as modifying the pt tip to accept and oring between it and the power tube -- kind of like a lvl10 oring carrier but inside out.

[WetPaint]

Now that is a very good point. I imagine that the difference in diameters is at least a couple thousands. I don't know how much air can get out of there during a firing cycle, but it has crossed my mind that in this case having a hollowed bolt might be an advantage.

If you put a soft "seal" at the end of the power tube, just wider than the pt tip, it would slide cleanly inside the hollowed out section of the bolt, but would seal against narrower back of the bolt when the bolt came all the way forward to fire. It might be as simple as modifying the pt tip to accept and oring between it and the power tube -- kind of like a lvl10 oring carrier but inside out.

Consider this.. With the older bolts, the leakage path through this PT-bolt gap is much longer than with the level 10. I'm not sure what the effect is of shortening a constricted gas flow passage is, but the L10 has to have more leakage to the rear.. To seal this, you'd need an O-ring in the rear of the bolt itself, since the leakage begins when the chamber is "uncorked".

One possible way to test this theory:
Seal off the front end of both bolt types by installing a plug in place of the foamie. Squeeze the trigger and hold, noting how long it takes for the bolt to return. If the L10 bolt leaks to the rear more then the standard, it should return more quickly.

[the electrician]

on my lvl 10, I noticed that the round part of the power tube tip is still in the bolt enough that it is about .090" into the hollowed out part of the bolt, when the air is able to come out of the power tube tip in full, to fire the ball.

so I thinkan o-ring on the back end of the power tube tip would seal this leakage.

or possibly, one could make a delrin sleeve to fit inside the bolt to mostly fill in the hollowed part of the bolt. but make it lose fitting, except near the back. make it a tighter fit, only .001" tolerance or so. this would get rid of the extra volume in the bolt and most of the bolt rearward leakage.but this of course would be a custom part, specific to each power tube and bolt.

I would like to get rid of all the air leaks in the design. air is able to leak out the front and back of the bolt before the full air release occurs. don't know if that's really feasible though.

the problem with this stuff is who is going to take the chance to test it? who's going to buy a lvl 10 and use it as a guinea pig?
I'm ususally fairly brave in this "willing" department, but financially, not very "able".

[Dayspring]

That's kinda how the level 10 actually works though...

I would like to get rid of all the air leaks in the design. air is able to leak out the front and back of the bolt before the full air release occurs. don't know if that's really feasible though.