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Old 11-04-2013, 03:35 PM   #831 (permalink)
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Originally Posted by J4 Paintball View Post
You know now paintballers and math mix. First kid off the field says he shot 3, the second shot 2, the third shot 1, and the other two also shot 2.

But there was only 5 on the other team...
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Old 11-05-2013, 11:35 AM   #832 (permalink)
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Originally Posted by J4 Paintball View Post
You know now paintballers and math mix. First kid off the field says he shot 3, the second shot 2, the third shot 1, and the other two also shot 2.

But there was only 5 on the other team...
Or it goes like this I shot four and then then got out. Get off the field only to find out my own team mate shot me. ( always bring your team jersey or you look like the other guys) lol
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Old 11-06-2013, 11:33 PM   #833 (permalink)
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Quote:
Originally Posted by J4 Paintball View Post
A few bits: This is a new design, entirely. It takes a bit to understand the dynamics. That being said...
The dynamics of a properly designed blow back take longer to process than a spool valve IMHO.

Quote:
Originally Posted by J4 Paintball View Post
Most guns cycle faster with paint because the back pressure keeps the valve chamber filled, requiring less air to fully recharge it. Due to this design, even more so, since the valve chamber pressure is also what returns the bolt.
This has not been my experience although I look forward to any data you might have.

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Originally Posted by J4 Paintball View Post
We tested the cps with both no back pressure and then varying degrees of back pressure - same gun would cycle 35cps fully without shoot down, with no back pressure, then up to 42cps with back pressure. So cycle speed increases with back pressure.
How can you test "shoot down" / "full shot" / "drop off" without firing a ball? Maybe you define these differently? I take shoot-down to mean a change/drop in ball velocity. "full shot" makes me think you were shooting a ball and measuring it's velocity. How was your test rig able to detect a full cycle when no ball was used?

I don't doubt your results in this rudimentary/empirical test scenario, only your assumptions as to the cause and assumptions regarding the design dynamics with paint.

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Originally Posted by J4 Paintball View Post
As shown on previous videos the gun cycles at 16bps no problem, and in fact in testing the it was able to cycle 21bps without a hitch - again, no eyes and just a rotor.

This will be plenty quick enough for everyday use, and so we reduced the forward pressure over a large portion of the stroke, slowing it down even more. Yet still we have no problem firing paint without eyes over 16bps.
So you shot a gun at 21BPS and assume there was no shoot-down or measured none? Not quite 30BPS. Was it a slower unit you fired at 16bps with eyes off that you measured(?) zero shoot-down? Have you done any testing with eyes ON at 15BPS to look at shoot-down with solenoid delay factored into the cycle time?

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Originally Posted by J4 Paintball View Post
... so some of the former assumptions do not apply.
No assumptions on my part. I look forward to any data you have collected.
I'm sure we're all fine if you refined the design with mostly trial and error, but some of us nerds love seeing when people invest the time into doing proper research. If that's what you did I'm surely not the only one that would love to see testing rig pics, charts, graphs, etc.

Best wishes.

Last edited by P0E; 11-06-2013 at 11:43 PM.
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Old 11-07-2013, 06:51 PM   #834 (permalink)
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POE -(looks for a facepalm emoticon)

You are over thinking it. Nothing in the dynamics for the timing is much different then any stacked tube guns when it comes to CPS or BPS. The limit for the gun, at the maximum setting, like most guns is the hopper.
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Old 11-08-2013, 12:13 AM   #835 (permalink)
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I can't wait to see this come to market and hope to get my hands on one for at least a little test drive at a chrono station
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Old 11-08-2013, 11:06 AM   #836 (permalink)
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Quote:
Originally Posted by J4 Paintball View Post
POE -

You are over thinking it. Nothing in the dynamics for the timing is much different then any stacked tube guns when it comes to CPS or BPS. The limit for the gun, at the maximum setting, like most guns is the hopper.
There's no such thing as "over thinking", only the opposite.

The initial quote, which you appear to have missed, added context. Below is a modified repost that might help. The other points can also be reworded if needed.

Quote:
Originally Posted by J4 Paintball View Post
A few bits: This is a new design, entirely. It takes a bit to understand the dynamics. That being said...
The dynamics of a properly designed blow back take longer to comprehend than that of a spool valve IMHO. i.e. It's easy to see the speed limitations in this design.

Quote:
Originally Posted by J4 Paintball View Post
Most guns cycle faster with paint because the back pressure keeps the valve chamber filled, requiring less air to fully recharge it. Due to this design, even more so, since the valve chamber pressure is also what returns the bolt.
This has not been my experience. Although I look forward to any data you might or might not have.

Quote:
Originally Posted by J4 Paintball View Post
We tested the cps with both no back pressure and then varying degrees of back pressure - same gun would cycle 35cps fully without shoot down, with no back pressure, then up to 42cps with back pressure. So cycle speed increases with back pressure.
How can you test "shoot down" / "full shot" / "drop off" without firing a ball? Maybe you define these differently? I take shoot-down to mean a change/drop in ball velocity. "full shot" makes me think you were shooting a ball and measuring it's velocity. How was your test rig able to detect a full cycle when no ball was used?

I don't doubt your results in this rudimentary/empirical test scenario, only your assumptions as to the cause and assumptions regarding the design's dynamics with paint.

Quote:
Originally Posted by J4 Paintball View Post
As shown on previous videos the gun cycles at 16bps no problem, and in fact in testing the it was able to cycle 21bps without a hitch - again, no eyes and just a rotor.

This will be plenty quick enough for everyday use, and so we reduced the forward pressure over a large portion of the stroke, slowing it down even more. Yet still we have no problem firing paint without eyes over 16bps.
So you shot a gun at 21BPS and assume there was no shoot-down or measured none? Not quite 30BPS. Was it a slower unit you fired at 16bps with eyes off that you measured(?) zero shoot-down? Have you done any testing with eyes ON at 15BPS to look at shoot-down with solenoid delay factored into the cycle time?

Quote:
Originally Posted by J4 Paintball View Post
... so some of the former assumptions do not apply.
No assumptions on my part. I look forward to any data you have collected.
I'm sure we're all fine if you refined the design with mostly trial and error, but some of us nerds love seeing when people invest the time into doing proper research. If that's what you did I'm surely not the only one that would love to see testing rig pics, charts, graphs, etc.

Best wishes.
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Old 11-08-2013, 11:58 AM   #837 (permalink)
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POE - it is a paintball gun, a low pressure piston cycling 26mm driven by a solenoid. It isn't rocket science.

The data you are looking for doesn't exist. Testing is done by adjusting up till there is failure or the setup doesn't complete a cycle or related. If you had my experience (20+ years) and were sitting with the other designer/machinist who designed the reg (he did make a 60cps reg that vents at Mach 2.5, tested by MIRA) and had cycled the gun tens of thousands of times like we have in a small office or at the chrony station, you can tell when there is shoot down, a full shot and other wise. It is obvious, especially as you turn up the ROF way past the limits.

We were tuning for a smooth gun that shot paint at 20+cps, knowing the hopper wouldn't feed much more then that, and the gun is limited to 15cps max almost anywhere. You add 20ms to the cycle time to feed, and get the total cycle time down to 50ms, or 30ms for the cycle. We knew we just had to hit 33cps to be okay. At 42cps the gun cycled without any noticeable change in firing signature, completed a full cycle, and was repeatable over many attempts, and we didn't push it past that. That is a 24ms cycle, and the setup felt solid and like it could cycle even faster.

Recharge of the reg was fine at 42cps, so it would be fine at 25bps, which uses less air due to back pressure and air trapping. Since some hoppers can load at 18ms, some playing with the eye programming can lower that also, and the rest of the cycle is at 24ms range, 25cps should be easy to hit. Though, we never maxed out the gun, so there is the potential for it to cycle faster.

Since we have done testing with eyes OFF, with paint, over a chrony, and not had drop off, at 20+cps, I think most of the rest of your assumptions are mute.

Eyes would slow down the gun, not speed it up. Running eyes off means it is directly an input of the timing - not slowed down to make it feed.

It is obvious that you do not understand the dynamic here, and have several things backwards.

For example - as we added back pressure (using an unported barrel section and varying the amount of back pressure by holding a cloth over it at different levels) we could up the max ROF by increasing the back pressure. This also increased the air efficiency. The affect was very easy to see.


Yes, many, many things are over thought. I have ran into that over decades of engineering in other fields, and working with engineers. When I left I had 3 working under me, believe me, anything can be over thought with them. Even ordering lunch.

The mistake is thinking you are not over thinking it.
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Old 11-08-2013, 01:15 PM   #838 (permalink)
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Quote:
Originally Posted by J4 Paintball View Post
POE - it is a paintball gun, a low pressure piston cycling 26mm driven by a solenoid. It isn't rocket science.

The data you are looking for doesn't exist. Testing is done by adjusting up till there is failure or the setup doesn't complete a cycle or related. If you had my experience (20+ years) and were sitting with the other designer/machinist who designed the reg (he did make a 60cps reg that vents at Mach 2.5, tested by MIRA) and had cycled the gun tens of thousands of times like we have in a small office or at the chrony station, you can tell when there is shoot down, a full shot and other wise. It is obvious, especially as you turn up the ROF way past the limits.

We were tuning for a smooth gun that shot paint at 20+cps, knowing the hopper wouldn't feed much more then that, and the gun is limited to 15cps max almost anywhere. You add 20ms to the cycle time to feed, and get the total cycle time down to 50ms, or 30ms for the cycle. We knew we just had to hit 33cps to be okay. At 42cps the gun cycled without any noticeable change in firing signature, completed a full cycle, and was repeatable over many attempts, and we didn't push it past that. That is a 24ms cycle, and the setup felt solid and like it could cycle even faster.

Recharge of the reg was fine at 42cps, so it would be fine at 25bps, which uses less air due to back pressure and air trapping. Since some hoppers can load at 18ms, some playing with the eye programming can lower that also, and the rest of the cycle is at 24ms range, 25cps should be easy to hit. Though, we never maxed out the gun, so there is the potential for it to cycle faster.

Since we have done testing with eyes OFF, with paint, over a chrony, and not had drop off, at 20+cps, I think most of the rest of your assumptions are mute.

Eyes would slow down the gun, not speed it up. Running eyes off means it is directly an input of the timing - not slowed down to make it feed.

It is obvious that you do not understand the dynamic here, and have several things backwards.

For example - as we added back pressure (using an unported barrel section and varying the amount of back pressure by holding a cloth over it at different levels) we could up the max ROF by increasing the back pressure. This also increased the air efficiency. The affect was very easy to see.


Yes, many, many things are over thought. I have ran into that over decades of engineering in other fields, and working with engineers. When I left I had 3 working under me, believe me, anything can be over thought with them. Even ordering lunch.

The mistake is thinking you are not over thinking it.
Wait, what's for lunch again?
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Old 11-08-2013, 01:19 PM   #839 (permalink)
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