[cockerpunk]

IIRC bob didn't get 2500+ out of a 68/45. someone goldwaved it and counted that the pods measured like 110 rnds each, which comes out stunningly close to the LSET test (surpized even myself with that one). within a pod anyway ...

also, assuming 100% effienecy, a 68/45 tank only has about 2600-2700 rounds in it, so we are quickly approaching this level of performance.

i also agree with DannyD, its got to be shoot down.

[Leafy]

cockerpunk, on 25 January 2011 - 03:05 PM, said:

also, assuming 100% effienecy, a 68/45 tank only has about 2600-2700 rounds in it, so we are quickly approaching this level of performance.

No kidding. It really is too bad that we lost that thread where I did all the math out and determined that the protege was operating at ~80% efficiency. Its really amazing, paintball is rally they only time where I've ever seen something actually even think of approaching 100% thermodynamic efficiency.

[IhasAcellular]

cockerpunk, on 25 January 2011 - 03:05 PM, said:

IIRC bob didn't get 2500+ out of a 68/45. someone goldwaved it and counted that the pods measured like 110 rnds each, which comes out stunningly close to the LSET test (surpized even myself with that one). within a pod anyway ...

also, assuming 100% effienecy, a 68/45 tank only has about 2600-2700 rounds in it, so we are quickly approaching this level of performance.

i also agree with DannyD, its got to be shoot down.

I believe it was a 70/45 tank. The numbers seem to add up nearly perfectly (if I actually did the math correctly..haha)

[brycelarson]

if those numbers are correct on Bob's video then I think we can pretty reasonably say that it's not choking. Or at least it's not gaining any efficiency through choking the gun.

[cockerpunk]

'P0E, on 25 January 2011 - 03:08 PM, said:

cockerpunk, on 25 January 2011 - 03:05 PM, said:

...
also, assuming 100% effienecy, a 68/45 tank only has about 2600-2700 rounds in it, so we are quickly approaching this level of performance.
...

Assuming what ball weight and velocity?

yes, that would be correct

Leafy, on 25 January 2011 - 03:10 PM, said:

cockerpunk, on 25 January 2011 - 03:05 PM, said:

also, assuming 100% effienecy, a 68/45 tank only has about 2600-2700 rounds in it, so we are quickly approaching this level of performance.

No kidding. It really is too bad that we lost that thread where I did all the math out and determined that the protege was operating at ~80% efficiency. Its really amazing, paintball is rally they only time where I've ever seen something actually even think of approaching 100% thermodynamic efficiency.

well, if your thinking cycle effienecy, then you need to include all the losses in the compressor and filling and all that crap.

we are basically just talking about the expansion process in the gun, which is pretty reasonable to have high effienecy.

[Leafy]

cockerpunk, on 25 January 2011 - 03:51 PM, said:

Leafy, on 25 January 2011 - 03:10 PM, said:

cockerpunk, on 25 January 2011 - 03:05 PM, said:

also, assuming 100% effienecy, a 68/45 tank only has about 2600-2700 rounds in it, so we are quickly approaching this level of performance.

No kidding. It really is too bad that we lost that thread where I did all the math out and determined that the protege was operating at ~80% efficiency. Its really amazing, paintball is rally they only time where I've ever seen something actually even think of approaching 100% thermodynamic efficiency.

well, if your thinking cycle effienecy, then you need to include all the losses in the compressor and filling and all that crap.

we are basically just talking about the expansion process in the gun, which is pretty reasonable to have high effienecy.

But really how many systems do you know that even have expansion efficiency that high? Steam/super critical turbines certainly dont.

[brycelarson]

'P0E, on 25 January 2011 - 04:54 PM, said:

One thing to consider though. If the gun shot nothing but 2.9g paint @ 250FPS for Punkwork's test and someone else ran this test with 3.2g paint at 300fps, they would only get 62% as many shots. [b]

The form indicates a chrono speed of 280. Since the velocity is the ^2 part of the equation controlling velocity makes a larger difference than controlling mass.

That said, I do think that including a mass per ball field on the form would be a good idea. We've got brand and size.

This test is not designed to test two guns against each other unless they're shooting the same paint out of the same barre at the same velocity. There's simply no way to control enough variables to create a universal efficiency test.

[cockerpunk]

'P0E, on 25 January 2011 - 04:54 PM, said:

cockerpunk, on 25 January 2011 - 03:51 PM, said:

...
yes, that would be correct

To expand on that...

Max theoretical shot count :
3.2g @ 300fps = 2584 shots (91.5% efficient)

3.0g @ 300fps = 2756 shots (85.8% efficient)

2.9g @ 275fps = 3393 shots (typical weight and velocity, 69.7% efficient)

2.9g @ 250fps = 4105 shots (57.6% efficient)

Showing my work -
Energy in a 68ci tank @ 4500psi is pressure times volume
31.03MPa * 0.001114m^3 = 34567.42J

Energy of each 3.2g paintball at 300fps is half of mass times velocity squared
0.5 * 0.0032Kg * (91.44m/s)^2 = 13.378J

Assuming a 3.0g ball at 300fps
0.5 * 0.003Kg * (91.44m/s)^2 = 12.54J

Assuming a 2.9g ball at 275fps
0.5 * 0.0029Kg * (83.82m/s)^2 = 10.187J

Assuming a 2.9g ball at 250fps
0.5 * 0.003Kg * (76.2m/s)^2 = 8.42J


69ish percent efficient isn't that bad.

One thing to consider though. If the gun shot nothing but 2.9g paint @ 250FPS for Punkwork's test and someone else ran this test with 3.2g paint at 300fps, they would only get 62% as many shots.

1466 vs. 2365

Is that a significant margin of error for this test?

of course, thats why you dont switch paints and chrono speeds between tests.

if you use the same ball weight and velocity, the comparison of those two samples will still hold true. this isn't an absolute test, its a comparative test. the comparative results will be valid despite the sample bias both are suspected of.

This post has been edited by cockerpunk: 25 January 2011 - 08:52 PM

[MIBaller]

Can some one please explain to my why the SLP makes such a difference on the G6R to me it doesnt make much sence as the air from the tank goes through an HPR to lower the pressure maybe some one who is smarter than I am can explain exactly why?

[IhasAcellular]

From what i've heard....nobody knows...that includes Bob Long, and Ninja...

[Spider200081]

The SLP does work fine for dm's and ego's right? Just curious since I might be interested in getting a g6r and needing a new tank now would possibly get a slp aslong as it works fine with ego and dm markers. Well basically any 2 reg marker.

[MIBaller]

[quote name='MIBaller' date='25 January 2011 - 09:00 PM' timestamp='1296007213' post='1974032']
Can some one please explain to my why the SLP makes such a difference on the G6R to me it doesnt make much sence as the air from the tank goes through an HPR to lower the pressure maybe some one who is smarter than I am can explain exactly why?
[/quote]


Just out of curiosity how much does the tank's output pressure fluctuate?
[/quote]

Here's My point a Normal HP tank puts out around 850. The SLP puts out 275? That air has to go through an HPR first. So the output shouldnt effect much but consistency because the more you have to drop a pressure the more inconsisten you will be basically

850 to 150 will be less consisten than 275 to 150. So my thinking is there is a vent in the gun like the Autococker SR's and maybe HP cause the gun to vent more air but idk.

[brycelarson]

'P0E, on 26 January 2011 - 12:58 PM, said:

Mass
This test assumes the same brand of paint will be the same mass and diameter every time.

Consistency
These tests make a less consistent marker appear to be a less efficient marker. Why? Because a positive swing of Xfps expends proportionally more energy then a negative swing of Xfps saves.

no, the test doesn't assume the same diameter - that's why it's got a field to enter the diameter of the paint used in a test.

good point on the consistency. So yes, the consistency of the gun will effect this test to some degree.

'P0E, on 26 January 2011 - 12:58 PM, said:

Consistency could be +/- 0 FPS and the mass could still vary the results by 15%. i.e. a 1740 shot marker could result in a 2000 shot marker just due to using a different mass paintball.

the formula is .5M*V^2 - to to get the %15 change in energy you would need a 30% change in mass. I'm hoping that people aren't using paint that varies by 30% ball to ball on this test.

[ninjapaintball]

Spider200081, on 26 January 2011 - 12:20 AM, said:

The SLP does work fine for dm's and ego's right? Just curious since I might be interested in getting a g6r and needing a new tank now would possibly get a slp aslong as it works fine with ego and dm markers. Well basically any 2 reg marker.

have not heard about the dms but we think no. we have shoot it on an ego and it was OK but would stick to the g6r and the victorys.

[MIBaller]

'P0E, on 26 January 2011 - 04:50 PM, said:

MIBaller, on 26 January 2011 - 01:10 PM, said:

...

Here's My point a Normal HP tank puts out around 850. The SLP puts out 275? That air has to go through an HPR first. So the output shouldnt effect much but consistency because the more you have to drop a pressure the more inconsisten you will be basically

850 to 150 will be less consisten than 275 to 150. So my thinking is there is a vent in the gun like the Autococker SR's and maybe HP cause the gun to vent more air but idk.

I have a hypothesis that can only be verified by the tank's output fluctuation. Even more telling would be to compare each ball's energy with this value.

brycelarson, on 26 January 2011 - 01:54 PM, said:

'P0E, on 26 January 2011 - 12:58 PM, said:

Mass
This test assumes the same brand of paint will be the same mass and diameter every time.

Consistency
These tests make a less consistent marker appear to be a less efficient marker. Why? Because a positive swing of Xfps expends proportionally more energy then a negative swing of Xfps saves.

no, the test doesn't assume the same diameter - that's why it's got a field to enter the diameter of the paint used in a test.

You are correct. Typo on my part. Fixed

good point on the consistency. So yes, the consistency of the gun will effect this test to some degree.

Consistency on the first portion of the test, 'choking'/shoot-down on the second 'real world' portion? What word are we using for velocity drop due to tank conditions?

'P0E, on 26 January 2011 - 12:58 PM, said:

Consistency could be +/- 0 FPS and the mass could still vary the results by 15%. i.e. a 1740 shot marker could result in a 2000 shot marker just due to using a different mass paintball.

the formula is .5M*V^2 - to to get the %15 change in energy you would need a 30% change in mass. I'm hoping that people aren't using paint that varies by 30% ball to ball on this test.

I think you're mistaken.

Try getting a pressure tester from techt to find out

[brycelarson]

'P0E, on 26 January 2011 - 04:50 PM, said:

the formula is .5M*V^2 - to to get the %15 change in energy you would need a 30% change in mass. I'm hoping that people aren't using paint that varies by 30% ball to ball on this test.

I think you're mistaken.

maybe, let's do some math and find out.

Ok, so %15 change in energy - let's us 10 joules and 11.5 joules. We'll keep the velocity constant - 90 m/s.

10 = .5x*90^2 so x = 2.47g
11.5 = .5x*90^2 so x = 2.84g

yup, you're right - %15 difference in joules 15% diff in mass.

[cockerpunk]

'P0E, on 26 January 2011 - 12:58 PM, said:

Please read all of this carefully. I'm not one of those people claiming 12 digits of precision are needed or that you need to include unrealistic variables that only impact results by 0.0001%. What I'm saying is that some of your test rely too heavily on untested assumptions. In this case, the myth of mass and velocity not changing by any significant degree.

..and..

If you include velocity and average mass you will have an 'absolute test' that produces repeatable and transferable results omitting no significant variables.

Mass
This test assumes the same brand of paint will be the same mass and diameter every time.
This is not true even for higher quality paint. Manufacturers really do try to produce the most consistent paintball. Unfortunately there's only so much they can do. I have measured RPS Premium and Marballizer Paintballs with weight differences of 5%, IN THE SAME BOX. The Premium has steadily declined in weight from >3.25g to <3.0g over the years. My latest batch was consistent but only averaged 2.95g! That's a 10% change for the same paint.

Velocity
Consistency of +/-5FPS (as defined in your test) is a small enough variation that velocity could be set at 280 and ignored. Unfortunately most markers are lucky to be under +/- 15fps and their velocity decreases to 220FPS as per the test. A drop of 60FPS or 30FPS swings are not insignificant energy changes.

Consistency
These tests make a less consistent marker appear to be a less efficient marker. Why? Because a positive swing of Xfps expends proportionally more energy then a negative swing of Xfps saves.
The G6R looks like it was roughly +/-30FPS. Assuming consistency improves down the road, your later tests will show an increase in efficiency even if its efficiency actually slightly decreased.

Shootdown
Here is a rhetorical question. Marker Y maintains 280FPS until it's out of air and marker Z (or marker Y at a later date) drops steadily to 220FPS. They get the same shot count. What one is more efficient and by how much?
Your test assumes the next G6R test will have the same consistency and 'shoot-down/choking'.

I understand you saying this is not an "absolute test", but the results are only comparable if the guns' shot velocity^2 sum is identical. What's the chance of that? As their shot velocities change the test results become more and more disjointed.


Absolute test
To measure efficiency all that's needed is energy input and energy output. Energy input is easy. It's just starting tank pressure minus ending tank pressure multiplied by tank volume. Temperature can be used to scale it as needed. Since most tests will only vary by 40F(10% or +/-5%), it's not really needed and can just be contributed to error.

Energy out is just the sum of each ball's energy. Use half the average mass times the square of each shot velocity.

Once ball fit (e.g. +0.002" underbore) and air supply is defined, you have the perfect efficiency test. Any tank at any pressure can be used. Any barrel can be used and (pulling from your previous barrel tests) we can make safe assumptions regarding changes. No other significant variables are missing.

brycelarson, on 25 January 2011 - 05:03 PM, said:

'P0E, on 25 January 2011 - 04:54 PM, said:

One thing to consider though. If the gun shot nothing but 2.9g paint @ 250FPS for Punkwork's test and someone else ran this test with 3.2g paint at 300fps, they would only get 62% as many shots. [b]

The form indicates a chrono speed of 280. Since the velocity is the ^2 part of the equation controlling velocity makes a larger difference than controlling mass.

That said, I do think that including a mass per ball field on the form would be a good idea. We've got brand and size.

This test is not designed to test two guns against each other unless they're shooting the same paint out of the same barre at the same velocity. There's simply no way to control enough variables to create a universal efficiency test.

Consistency could be +/- 0 FPS and the mass could still vary the results by 15%. i.e. a 1740 shot marker could result in a 2000 shot marker just due to using a different mass paintball. Since consisency was likely roughly +/-30fps during the first portion and slowly dropped an additional 60FPS during the second portion, velocity was far from held constant.
This test's error when comparing two guns with the same brand paint out of the same barrel at the same average velocity is roughly +/-50%.

MIBaller, on 25 January 2011 - 09:00 PM, said:

Can some one please explain to my why the SLP makes such a difference on the G6R to me it doesnt make much sence as the air from the tank goes through an HPR to lower the pressure maybe some one who is smarter than I am can explain exactly why?

Just out of curiosity how much does the tank's output pressure fluctuate?

Fixed - Current test only assumes consistent mass and identical velocities, not ball diameter.

no, i think your missing the prupose of the test. we are comparing the SLP regulator to the normal output regulator. NOTHING MORE. so provided the paintball mass doesn't change much (same paint) and chrono speed doesn't change (we can measure this directly), that means that those two samples will be fair to compare to each other. and from that comparision we can decide if the SLP is more, less, or about the same effinecy as the normal reg.

however, i do get your point when comparing or extrapolating these resualts to full tanks, and with other guns and such. maybe this is what is freaking you out. however, we are making a passing observation that the extrapolated LSET test is very comprable to bob longs actual testing. that doesn't mean anything other then that this time it seems to have worked well, however, there are many cases where it wont predict well. more correctly, it will predict effienecy of a setup well, however, tiny varaibles in the setup will change the effienecy signifcantly.

This post has been edited by cockerpunk: 27 January 2011 - 12:41 PM

[bigschank]

Everyone is forgetting 3 things...sigh

• Wind speed
  
• Dow Jones Industrial Average
  
• If cockerpunk had a good shit that morning

I feel like an ass because i had to point this out to all you "smart guys"...oh well


hehe

This post has been edited by bigschank: 27 January 2011 - 10:59 AM

[cockerpunk]

'P0E, on 27 January 2011 - 02:20 PM, said:

cockerpunk, on 27 January 2011 - 10:42 AM, said:

...


no, i think your missing the prupose of the test. we are comparing the SLP regulator to the normal output regulator. NOTHING MORE. so provided the paintball mass doesn't change much (same paint) and chrono speed doesn't change (we can measure this directly), that means that those two samples will be fair to compare to each other. and from that comparision we can decide if the SLP is more, less, or about the same effinecy as the normal reg.

My comments were more directed to your LSET as a tool not specifically in regard to this use of it.

Although this use is more simplistic I still feel the results are well within the margin of error.

The shot count could have been identical with some very minor and easily overlooked changes (+0.09g mass change, +/-9fps consistency change, 220 vs 250 ending velocity).

Now I'm sure that Bob Long wouldn't risk his reputation on such an easy to test product. It's highly likely that he put thousands of balls through that gun to discover/verify this. As you stated, I just caution against forming any efficiency gain 'guess' primarily due to the test's massive margin of error.

I agree completly, i find the resualts well within the margin of error of the test. or to the point that when scaled up, there will be little effective gain.


however, i do get your point when comparing or extrapolating these resualts to full tanks, and with other guns and such. maybe this is what is freaking you out. however, we are making a passing observation that the extrapolated LSET test is very comprable to bob longs actual testing. that doesn't mean anything other then that this time it seems to have worked well, however, there are many cases where it wont predict well. more correctly, it will predict effienecy of a setup well, however, tiny varaibles in the setup will change the effienecy signifcantly.

I understand what you are saying about only being able to test the entire setup and not just the gun. Since not every barrel/tank/reg is identical, you will always run into this regardless of the test method. In fact it should be noted somewhere that it's a system not gun efficiency test.

It's also understandable that small variables will effect test results to some degree. Wind, for example, can effect accuracy results to a degree proportional to the wind's intensity. I'm sure you would be highly skeptical of an outdoor accuracy test that did not document wind level. All I'm advocating is that the test be done indoors so-to-speak..

Other than the additional effort involved, do you have any concerns with the efficiency test I have proposed?

Do you see any variable that would prevent the results from being repeatable or transferable?

It would be great if Mike's efficiency tests included this information. We could get a real idea as to how the guns compare and how ROF influences efficiency. I guess he would need a chrony with a PC output. We would get an idea of the gun's consistency and shootdown as well. That would be nice.

well, the fundamental problem is that many things effect effienecy. right? so without either specifying or controlling all these things you test is going to have a wide variety of outcome with any given gun. i dont think there is any good way around that, but it would be interesting to take a similar setup, and use three different weigths of balls, and three different chrono speeds and see exactly how they effect the outcomes.

^^^in bold

[Cookybiscuit]

So it is a little bit of a difference, it dosent seem big but you might get an extra pod of a 68/45 with the other reg.