So I was Thinking about a New Gun Design.....

[nerobro]

*complications*
*sensors*

With all this talk of injectors, it would be instructive to realize why injectors are used in cars in the first place -- for consistent and controllable atomization of fuel. With a combustion engine you are dealing with a whole different ball of wax compared to a paintball gun -- you are concerned with the fuel-air emulsion, which is a complete non-issue in paintball. With paintball, all you need is consistent metering and good flow; that can be achieved even mechanically just as well as electronically.

Off the top, the injector method would reduce parts count. Active seals in the gun would drop from anywhere from two, to a dozen, down to one. The need for good lubrication would diminsh, if not vanish entirely. Using an electronically controlled valve is simpler.

The sensors... well.. I don't think they're needed, marketable, or even a good idea. Rigs like that are good for development, not for pushing bunkers aside or diving through underbrush.

Cars went to fuel injection not for the reasons you mention. Carburators are magical devices when it comes to getting good fuel distribution. A properly setup carb, and efi both have the same horsepower potential. Due to how they're built, carbs, quite nearly by defualt, have wonderful emulsion properties. EFI needs a lot of enginering to get there.

Paintball, as an industry, has figured out how to make mechanical systems that meter high pressure air with remarkable repeatability. However, being static valve designs, they can only meter air one way. A vector, or rainmaker, will always be loud. A mag, will always have it's distinctive pop. Now, if you want to think about what an electronically controlled valve can do, think about the different sound signatures that cockers have. Some bang, others whisper. This valve could do both, on demand. With less complication. With as few as two moving parts.

In the end, this would be a uniquely AGD thing. Hah, A Crystal AIR valve. :-) Something that would require even less maintenance than the original one.

If AGD wanted to come back on the scene a good place to start might be re-engineering the pump mag.

Possibly built around a tiny all aluminum classic valve ???

This defeats the purpose of retaining the AIR in the first place. If it's tiny, it's not compatible with the rest of the mag family. At that point, why bother with the AIR, when todays machining techniques could allow you to just make the whole gun in one lump?

I "get" the pumpmag. The pumpmag isn't a great pumpgun. It's consistent, but it's loud, and not terribly good on gas, it's heavy (for a pumpgun), and it could fail in some interesting ways. It was a very, very neat trick that took advantage of a problem the mag had. I've always kinda seen the pumpmag as a very cool parlor trick.

The injector design could do the pump thing with even less effort.

EDIT:
anyone else ponder the resemblance of those diesel injectors with the AIR valve? not saying anything beyond that... just... conversion kits? ;-)

[AGD]

Without feedback electronic control is useless in my opinion. I have come up with an idea to measure the velocity WITHOUT using eyes, sensors on the barrel or anything ugly. I would envision that you push the "reset velocity" button and start firing the gun over a crono. The velocity will go up with every shot and when you hit 280 or 300 FPS you stop firing and now the gun has the info it needs to adjust for velocity.

If you change barrels or paint, you do the same thing and your good to go. Continue the discussion with the idea that you know what the balls velocity is every shot.

AGD

[drg]

Off the top, the injector method would reduce parts count. Active seals in the gun would drop from anywhere from two, to a dozen, down to one. The need for good lubrication would diminsh, if not vanish entirely. Using an electronically controlled valve is simpler.

Is this a significant issue? Not really. First off it's unlikely that there would be only one active seal in the final design. The balls have to load somehow. Second, active seals at several times have been marketing points for paintball guns but in the end number of active seals has not necessarily amounted to a significant advantage of one design over another. Miniaturized solenoids have become reliable enough to not be issues, and most poppet design guns have 2 required active seals other than the solenoid. A sniper has 1.

Is an electronically controlled valve simpler than mechanical control? Arguably not.

Cars went to fuel injection not for the reasons you mention. Carburators are magical devices when it comes to getting good fuel distribution. A properly setup carb, and efi both have the same horsepower potential. Due to how they're built, carbs, quite nearly by defualt, have wonderful emulsion properties. EFI needs a lot of enginering to get there.

Read what I wrote again. I said nothing about the quality of the emulsion. But you've successfully missed the point. Emulsions are NOT paintball issues. This is a solution to a problem that doesn't exist.

Paintball, as an industry, has figured out how to make mechanical systems that meter high pressure air with remarkable repeatability. However, being static valve designs, they can only meter air one way. A vector, or rainmaker, will always be loud. A mag, will always have it's distinctive pop. Now, if you want to think about what an electronically controlled valve can do, think about the different sound signatures that cockers have. Some bang, others whisper. This valve could do both, on demand. With less complication. With as few as two moving parts.

Is selectable sound signature a reason to do this? No. One would be more than a little silly to reinvent the wheel to do this. Variable normal operating pressure has no inherent point. One no longer has to trade off between pressure/sound signature and efficiency, so this ship has long sailed.

In the end, this would be a uniquely AGD thing. Hah, A Crystal AIR valve. :-) Something that would require even less maintenance than the original one.

I daresay that uniqueness for its own sake is antithetical to what has made AGD products successful and long-lived.

[drg]

Without feedback electronic control is useless in my opinion. I have come up with an idea to measure the velocity WITHOUT using eyes, sensors on the barrel or anything ugly. I would envision that you push the "reset velocity" button and start firing the gun over a crono. The velocity will go up with every shot and when you hit 280 or 300 FPS you stop firing and now the gun has the info it needs to adjust for velocity.

If you change barrels or paint, you do the same thing and your good to go. Continue the discussion with the idea that you know what the balls velocity is every shot.

AGD

So, in other words you chrono the gun to set the velocity? How is that different from, let alone better than, the way any other gun works?

What would be the point of this? And again, what would the feedback loop do? In a normal paintgun setup, the variance between shots is not sourced to any actively controllable parameter ... guns are set up for consistent pressure and dwell. If you get a low shot it's due to either fluctuation in one of those parameters or a ball inconsistency, or other random factor. Trying to actively compensate for that would be introducing inconsistency.

[snoopay700]

Without feedback electronic control is useless in my opinion. I have come up with an idea to measure the velocity WITHOUT using eyes, sensors on the barrel or anything ugly. I would envision that you push the "reset velocity" button and start firing the gun over a crono. The velocity will go up with every shot and when you hit 280 or 300 FPS you stop firing and now the gun has the info it needs to adjust for velocity.

If you change barrels or paint, you do the same thing and your good to go. Continue the discussion with the idea that you know what the balls velocity is every shot.

AGD

The problem i foresee is that the gun will be estimating how much air needs to be let through to truly shoot to the bottom of the tank, ad having a board that varies the dwell as it is working is dangerous because if the algorithm is off at all then the marker could very well start shooting hot and there would be no way to know. Having a pressure sensor inside could effectively let you know how much pressure you have but again, you run into a lot of variables that would be very hard to account for. I'm not saying it couldn't be done, it's just very dangerous. If you had a set dwell that didn't change that would be one thing, but for a changing dwell i wouldn't feel good marketing something like that as the marker will be guessing more or less. I would prefer to have a way to check that the marker is still shooting at a safe velocity, it would be ugly but it would be a lot safer.

[nerobro]

Chrono Proceedure

I'm sure it would mess with people over the chronograph. The "increase every shot till you hit the set button" method seems good. it would definitely discourage on field velocity adjustments. You'd need to make sure the velocity starts way low every time you reset, assuring that one couldn't just "guess" on field.

The current peizo valves run to roughly 25,000psi. To bad fields can't fill that high ;-)

I wonder how badly the flow rate tapers off as tank pressures drop. I wonder how high flow the valve could be modified to run at, for lower pressures. I'm sure there's plenty of room to make the tips larger to get a bigger seat diameter so flow rates would be reasonable at the 1000-4500psi range that we could expect...

Is this a significant issue? Not really. First off it's unlikely that there would be only one active seal in the final design. The balls have to load somehow. Second, active seals at several times have been marketing points for paintball guns but in the end number of active seals has not necessarily amounted to a significant advantage of one design over another. Miniaturized solenoids have become reliable enough to not be issues, and most poppet design guns have 2 required active seals other than the solenoid. A sniper has 1

I dunno. Early ions and the like had/have solinoid life problems. So did impulses. Pneumatic solinoids are quite reliable, but the sort of designs that you find in fuel injectors are more reliable by magnitudes. Think millions of cycles instead of tens of thousands. With a small number of active seals, making reliability claims is easy. It's not a big issue, but it's one that can differentiate a gun from another.

Is an electronically controlled valve simpler than mechanical control? Arguably not.

An electronically controlled valve will ALWAYS give the same valve duration. This can not be said about most of the pneumatically operated, and even some of the spring operated guns out there. Dirt, lube issues, stiction... all add up to inconsistencies in operation. This would not be true for a peizo operated valve. This leads onto the next jewel...

Read what I wrote again. I said nothing about the quality of the emulsion. But you've successfully missed the point. Emulsions are NOT paintball issues. This is a solution to a problem that doesn't exist.

You seem concerned that the technology was designed for one specific fluid. I don't think that matters. I will drop the terminology of "injector" if that bothers you.

I've gone back and re-read what you said. I think you missed the point behind efi. I was pointing out that efi didn't do a better job than mechanical control in certain applications. You did make that point as well. I assumed you gathered the rest. But to detail it... EFI has it's advantages because you know exactly how much fuel you're dispensing.

This is exactly the advantage an electronic valve system would have. The AIR valve was designed based on repeatability. Fill a given chamber to X pressure, and you will get X velocity. An electronically controlled valve body could potentially give even better performance.

Is selectable sound signature a reason to do this? No. One would be more than a little silly to reinvent the wheel to do this. Variable normal operating pressure has no inherent point. One no longer has to trade off between pressure/sound signature and efficiency, so this ship has long sailed.

Actually, that's something that TK brought up in his initial post. I wouldn't see it as a vital feature, it's just something that could be fairly easily done. I don't understand where you're reaching for with the operating pressure statement. Operating pressure really didn't have a whole lot of bearing on how much noise a gun made.

I daresay that uniqueness for its own sake is antithetical to what has made AGD products successful and long-lived.

And... we can point at the pumpmag. But in this case, the electronic valve would provide a more reliable way of providing what the AIR always gave us.

*grumbles about not having the toold on hand to build this now* I've got the electronics, just no test barrel or injector. :-/

The problem i foresee is that the gun will be estimating how much air needs to be let through to truly shoot to the bottom of the tank, ad having a board that varies the dwell as it is working is dangerous because if the algorithm is off at all then the marker could very well start shooting hot and there would be no way to know. Having a pressure sensor inside could effectively let you know how much pressure you have but again, you run into a lot of variables that would be very hard to account for. I'm not saying it couldn't be done, it's just very dangerous. If you had a set dwell that didn't change that would be one thing, but for a changing dwell i wouldn't feel good marketing something like that as the marker will be guessing more or less. I would prefer to have a way to check that the marker is still shooting at a safe velocity, it would be ugly but it would be a lot safer.

This is where science is our friends. And more importantly, good testing and data collection. The valve will flow differently at all input pressures. I'd hope that the flow rates would be same enough over say.. 10's of psi that we could use cheap sensors, and inexpensive AD inputs. Once you've set the velocity, the gun would know the input pressure, and valve duration to make the ball go X fps. Knowing the flow rate of the valve, we could make the ball go X fps for essentially any input pressure. If the math is wrong, yes, it could be dangerous. However, the same could happen with a matrix, angel, or timmy. If the dwell is to long, you end up with higher velocities. This guns valve design can't have FSDO.

I wouldn't be so worried about the board, as I would be the sensors. If those drifted, that would upset me. How would we handle that? How would we calibrate them? How

Thankfully air is predictable. Now, it's flow is fairly linear over high pressure differentials, say from 2100 to 2200 psi you'd get a fairly straight curve. Flow rate from 100psi to 200psi is going to be exponentially slower. This would make knowing what the absolute input pressure is pretty important. .... Maybe just writing the tables to be a little conservative would account for being 50-100psi off of PSIg. And say.. have the gun shutdown at 500 or 700 psi, instead of running into the "our math doesn't work so well here" reigons.

[drg]

I dunno. Early ions and the like had/have solinoid life problems. So did impulses. Pneumatic solinoids are quite reliable, but the sort of designs that you find in fuel injectors are more reliable by magnitudes. With a small number of active seals, making reliability claims is easy. It's not a big issue, but it's one that can differentiate a gun from another.

The Ion was a budget marker, and the impulse's problems date back almost a decade. Both were resolved. These are not things that support shying away from pneumatic solenoids. Today's solenoids are fine.

An electronically controlled valve will ALWAYS give the same valve duration. This can not be said about most of the pneumatically operated, and even some of the spring operated guns out there. Dirt, lube issues, stiction... all add up to inconsistencies in operation. This would not be true for a peizo operated valve.

Not always ... lose power stability (or lose power entirely) and you lose consistent operation. This is the most basic complication of electronic operation of any marker. In practice mechanical inconsistencies are not problematic enough (on good markers) to warrant any concern whatsoever.

You seem concerned that the technology was designed for one specific fluid. I don't think that matters. I will drop the terminology of "injector" if that bothers you.

You can drop the terminology if you like, but you're best off dropping the misconceptions. Injectors are not just fluid metering devices. Fuel injectors for example atomize fuel upon delivery. That is why they are designed and employed the way they are. There are far more considerations than a paintball firing valve, which IS largely just a fluid metering device.

I've gone back and re-read what you said. I think you missed the point behind efi. I was pointing out that efi didn't do a better job than mechanical control in certain applications. You did make that point as well. I assumed you gathered the rest. But to detail it... EFI has it's advantages because you know exactly how much fuel you're dispensing.

Fuel injection's primary advantage was the divorcement of atomization/emulsification from airflow. Further refinements such as port or direct injection improved upon that by delivering emulsion directly to the ports or combustion chambers, avoiding inefficiencies such as pooling. None of this has any analogue in paintball.

This is exactly the advantage an electronic valve system would have. The AIR valve was designed based on repeatability. Fill a given chamber to X pressure, and you will get X velocity. An electronically controlled valve body could potentially give even better performance.

Simple electronic fluid metering does not require anything resembling an injector structure. We already have such a device in the mQ valve or other electronically controlled firing valves.

Actually, that's something that TK brought up in his initial post. I wouldn't see it as a vital feature, it's just something that could be fairly easily done. I don't understand where you're reaching for with the operating pressure statement. Operating pressure really didn't have a whole lot of bearing on how much noise a gun made.

The OP asserted a linkage between operating pressure and both efficiency and sound signature. It is exactly my point that while that was conventional wisdom years ago, there is no such linkage today.

[nerobro]

You're right, fuel injectors are designed with squirting fuel in mind. Definitely the valve design isn't ideal for "fueling" a paintball gun. But it should be adequate for proof of concept. I've grabbed onto these peizo injectors for a reason, they're fast enough for us to pull some really fancy tricks with their flow rate.

The MQ valve I had forgotten about. And that is a good design too. As I recall it is dependent on good regulation to feed it. An injector wouldn't need that. (it would just need a good sensor to tell it input pressure..)

The injector design could also be used as a regulator that could retrofit on n2 tanks.... That would be interesting. Now if we could only power it without a big battery pack ;-)

[oldironmudder]

The injector design could also be used as a regulator that could retrofit on n2 tanks.... That would be interesting. Now if we could only power it without a big battery pack ;-)

Now I would like to see this.

[snoopay700]

This is where science is our friends. And more importantly, good testing and data collection. The valve will flow differently at all input pressures. I'd hope that the flow rates would be same enough over say.. 10's of psi that we could use cheap sensors, and inexpensive AD inputs. Once you've set the velocity, the gun would know the input pressure, and valve duration to make the ball go X fps. Knowing the flow rate of the valve, we could make the ball go X fps for essentially any input pressure. If the math is wrong, yes, it could be dangerous. However, the same could happen with a matrix, angel, or timmy. If the dwell is to long, you end up with higher velocities. This guns valve design can't have FSDO.

I wouldn't be so worried about the board, as I would be the sensors. If those drifted, that would upset me. How would we handle that? How would we calibrate them? How

Thankfully air is predictable. Now, it's flow is fairly linear over high pressure differentials, say from 2100 to 2200 psi you'd get a fairly straight curve. Flow rate from 100psi to 200psi is going to be exponentially slower. This would make knowing what the absolute input pressure is pretty important. .... Maybe just writing the tables to be a little conservative would account for being 50-100psi off of PSIg. And say.. have the gun shutdown at 500 or 700 psi, instead of running into the "our math doesn't work so well here" reigons.

Yes, i know it can be done, but i question both how long the code will be for that sort of operation and if that will fit on a standard board. The other thing is that with angels and timmies and such, the dwell isn't varying from shot to shot. That means that you set the dwell and then you can adjust the input pressure and therefore can easily control the velocity. The dwell will never change, so it's not dangerous. Even with a lot of research and everything you could theoretically figure out how long to keep the valve open, but my worry is the huge number of variables that would need to be accounted for. I'm not saying it can't be done, just that putting out a product like that would make me worry, i would have to do a ton of extensive testing until i would be happy with it, and even then the variables would make me worry. Running only 2-400 psi below the output of most tanks doesn't seem all that worth the bother to me, going down into the ranges where the math wouldn't work well would,b ut that would also greatly increase the risk. I for one would feel much safer knowing that each shot is being measured and ensuring it is below 300fps, and with that it would make the program much shorter to write so it would fit, and the gun wouldn't be guessing.

[vf-xx]

Actually an Injector designed for atomization could be very VERY useful, if you're designing one to use liquid CO2.....

[Newt]

Propane?

[nerobro]

I don't understand the failure modes.

That's the thing, the dwell on those guns IS NOT static. Among other things that aren't static. such as input pressures, or even set pressures.

First off, regulators aren't perfect. And they have a curve to their recharge. As soon as those guns start firing, their valve chamber, and ram pressures start dropping. Sometimes precipitously. Some of the guns even have some dwell compensation built in, iirc.

Angels dropped their snap ring, and I think they've even dropped the spring. Timmys had no ram retention, still have none. These guns often have FSDO problems, and the "fix" for this is longer dwell on the first shot after a certain amount of time. FSDO, is effectively the same as varying valve open time on the inejctor design. That could not happen.

Now there are other things that vary the dwell on those guns. Stiction in the valve itself, as well as the ram. If the LPR creeps, that could cause a hot shot, or many hot shots. A failing reg seat could cause consistantly hot shots. A failing reg could do the same from the valve chamber side.

None of this could happen with an injector type gun. The "only" failure point that could cause that sort of thing, is the board locking up in such a way as to have the HV power supply turned on, and the fet connecting that to the injector turned on at the same time. It wouldn't take much magic to prevent that from ever happening. (such as using a software SMPS driver from the controller chip. if that locked up, the HV power supply would go away, and the gun would be incapable of actuating the valve)

I understand what you're saying, but what i'm hearing is FUD. You're not familiar with it, so you're fearful of the failure modes. Short of the device actually coming apart at the seams, it would be safer for other players than regulators and solenoid valves.

Something else to keep in mind, the electronic setup would have the same velocity untill it reached the "shutdown" pressure. On guns that use regulators, the velocity varies as the input pressure changes. Regulators have that whole pressure ratio thing. While having two regulators in line does help that, you're still looking at a several psi change over the course of a tank of air.

[drg]

Sometimes precipitously. Some of the guns even have some dwell compensation built in, iirc.

NO, HUGE NO. Pressure-related dwell compensation is strictly verboten. Regulators are selected to avoid recharge issues.

The rest of the stuff is simply non-issues. The reliability of current setups is simply not a concern.

[snoopay700]

That's the thing, the dwell on those guns IS NOT static. Among other things that aren't static. such as input pressures, or even set pressures.

First off, regulators aren't perfect. And they have a curve to their recharge. As soon as those guns start firing, their valve chamber, and ram pressures start dropping. Sometimes precipitously. Some of the guns even have some dwell compensation built in, iirc.

Angels dropped their snap ring, and I think they've even dropped the spring. Timmys had no ram retention, still have none. These guns often have FSDO problems, and the "fix" for this is longer dwell on the first shot after a certain amount of time. FSDO, is effectively the same as varying valve open time on the inejctor design. That could not happen.

Now there are other things that vary the dwell on those guns. Stiction in the valve itself, as well as the ram. If the LPR creeps, that could cause a hot shot, or many hot shots. A failing reg seat could cause consistantly hot shots. A failing reg could do the same from the valve chamber side.

None of this could happen with an injector type gun. The "only" failure point that could cause that sort of thing, is the board locking up in such a way as to have the HV power supply turned on, and the fet connecting that to the injector turned on at the same time. It wouldn't take much magic to prevent that from ever happening. (such as using a software SMPS driver from the controller chip. if that locked up, the HV power supply would go away, and the gun would be incapable of actuating the valve)

I understand what you're saying, but what i'm hearing is FUD. You're not familiar with it, so you're fearful of the failure modes. Short of the device actually coming apart at the seams, it would be safer for other players than regulators and solenoid valves.

Something else to keep in mind, the electronic setup would have the same velocity untill it reached the "shutdown" pressure. On guns that use regulators, the velocity varies as the input pressure changes. Regulators have that whole pressure ratio thing. While having two regulators in line does help that, you're still looking at a several psi change over the course of a tank of air.

I didn't know that about the boards, i knew that regs aren't perfectly consistent or static, but i didn't know the boards compensated. I've never owned an electronic marker and have never really looked at the programming on the boards, i figured the LPRs used were consistent enough at the speeds needed that the dwell would not vary much. I was talking with everything in working order in mind though, the failing valve seats and such are just that, failures. If something fails it is never safe, and i would put sticking of any kind going on in the same category.

I know there are many things that can vary the velocity, but the ones that aren't failures will not likely change it into the goggle busting range. Like i said, i know it can be done, but with all of the variables that would have to be dealt with it could be a huge risk, and not one worth the small number of shots you would get for that few hundred psi i think. Who knows, i may end up doing something like this on my marker. However, like i said i would have to do extensive testing to ensure it wouldn't miscalculate and go into the goggle busting range. However a chrono on the front of the gun would make the whole set up much safer because then you could definitely stop the marker from ever firing over 300 fps. I may just put one on the prototype of my marker in conjunction with the varied timing to record each shot and ensure none of them are going to a dangerous range, however i still like the idea of being able to fire a few shots and then fire a few over the chrono and be all set to go.