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Thread: A proposed measurement of performance

  1. #1
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    A proposed measurement of performance

    We have never had a universal measurement of performance for our markers. I propose a measurement based on how consistently a marker shoots (f.p.s.) from shot to shot based on a simple math formula that can not be disputed when provided through a series of chrono readings.

  2. #2
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    Look up variance and standard deviation.

  3. #3
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    Step 1: Find good paint.
    Last of the Salzburg Clan
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  4. #4
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    This is old, but still relevant:
    http://lennon.csufresno.edu/~nas31/nsa/pballIntro1.html

    And those calculations are based on every paintball being the same size, shape & weight...Which isn't true.
    CT Co-ordinator, Paintball Marshals

  5. #5
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    The measurement for performance standards lies with the RT valve. 26 balls per second without shootdown. It has never been beat and never will. If you can beat that then show me the video.
    Email me for low prices on ALL AGD Products and more. tunaman5@verizon.net
    Tunamart

  6. #6
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    Quote Originally Posted by Tunaman View Post
    The measurement for performance standards lies with the RT valve. 26 balls per second without shootdown. It has never been beat and never will. If you can beat that then show me the video.
    Devil's advocate: Perhaps, but this is on a marker not universally allowed for play.

    Step 1: Define rules of entry.
    Step 2: Find good paint.

  7. #7
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    Quote Originally Posted by Grizzly View Post
    We have never had a universal measurement of performance for our markers. I propose a measurement based on how consistently a marker shoots (f.p.s.) from shot to shot based on a simple math formula that can not be disputed when provided through a series of chrono readings.
    From shot to shot at different BPS. WHAT is the most consistent gun at 10 or 15 BPS?

    I asked this before.

    Here

    http://automags.org/forums/showthrea...-Who-can-do-it

    http://automags.org/forums/showthrea...-So-who-has-it

  8. #8
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    Calling goatboy.....
    "When injustice becomes law, resistance becomes duty." Thomas Jefferson

  9. #9
    Sorry I missed your call. Please leave your message at the beep.

    nak81783 pretty much pointed it out though: FPS variation will vary based on paint. In fact, I believe it actually dominates the shape of your distribution curve.

    For instance, I ran the same batch of paint through the same barrel, same day, but on 2 different markers here:



    Look at 2013-06-29, with Automag and Spyder. X is FPS, Y is frequency.

    The center of the curves (the velocity setpoint) were different, but the shape of both curves appear very, similar. Standard deviation was 6.17 vs 6.19.

    In that example, I was essentially holding the paint constant and varying the gun.

    Doing so in a repeatable, verifiable way (such that many people can reproduce and validate the results) is tricky. You only have so many shots before you have to open another bag, and who knows what you'll be getting with that second bag.

    You really need a reference sphere that everyone can obtain and agree on. And you need enough of them. And a reference barrel to go with that sphere.

    I think this came up in the CCM SR1 development as well. Read the description in the video -- "it ain't the gun".



    So you either have the reference sphere and reference barrel (which themselves require validation), or you find some way to measure and normalize results based on deviations from the reference. Uh... good luck with that, I guess?

    But the sad fact is most guns in a "modern" (oh god I'm starting to use that word now) configuration can easily do this task pretty well. Well enough that the error from the gun is probably dwarfed by by the error from just the paint/barrel. Paint nowadays is way better than it used to be, but it is still (measurably) imperfect.
    "Accuracy by aiming."


    Definitely not on the A-Team.

  10. #10
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    Quote Originally Posted by GoatBoy View Post
    nak81783 pretty much pointed it out though: FPS variation will vary based on paint.


    Satan called. Hell froze over.
    Last edited by nak81783; 07-15-2017 at 08:15 PM.

  11. #11
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    Quote Originally Posted by Tunaman View Post
    The measurement for performance standards lies with the RT valve. 26 balls per second without shootdown. It has never been beat and never will. If you can beat that then show me the video.

    https://www.youtube.com/watch?v=Yc2UyR22U00

  12. #12
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    Okay, where are the fps ratings of each shot proving no shootdown at 40 bps?

  13. #13
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    Ball stream and shot sound looked good enough..lol

  14. #14
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    Video says modified DM8. Any idea what the mods are, if they're legal, etc.? Just gotta be fair since I played devil's advocate against the RT Valve as well.

  15. #15
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    Probably had a extra high LPR pressure with a low dwell and blueprinted o'rings on the fusebolt.

    I'd still pick a 'mag over a DM (and i've owned them all bar the 11) any-day, mags are hassle free and always work once set up.

  16. #16
    Goatboy,

    Just out of curiosity, what barrel were you using on the mag/spider comparison day?

    Also, were you under- or overboring? I'm chasing a different rabbit and am wondering if our trails intersect.

  17. #17
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    Quote Originally Posted by GoatBoy View Post
    For instance, I ran the same batch of paint through the same barrel, same day, but on 2 different markers here:



    Look at 2013-06-29, with Automag and Spyder. X is FPS, Y is frequency.

    The center of the curves (the velocity setpoint) were different, but the shape of both curves appear very, similar. Standard deviation was 6.17 vs 6.19.

    In that example, I was essentially holding the paint constant and varying the gun.
    Those curves are interesting in that they are such nice bell curves. I have trouble believing that paint defects (or varying marker/barrel defects) would be so smoothly distributed. These look like consistently oblong paint being loaded into the breeches in a perfectly random fashion. Like out of a loader or something.

  18. #18
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    Quote Originally Posted by Spider-TW View Post
    Those curves are interesting in that they are such nice bell curves. I have trouble believing that paint defects (or varying marker/barrel defects) would be so smoothly distributed. These look like consistently oblong paint being loaded into the breeches in a perfectly random fashion. Like out of a loader or something.
    I could be wrong. But I'm pretty sure them are auto generated curves in excel based off of all of the points that are not as smooth. This way we have something clean to look at that represents the characteristics.

  19. #19
    Quote Originally Posted by Menace_AO View Post
    Just out of curiosity, what barrel were you using on the mag/spider comparison day?

    Also, were you under- or overboring? I'm chasing a different rabbit and am wondering if our trails intersect.
    It was effectively the same barrel -- I used a Cocker Freak back on the Mag, and a Spyder Freak back on the Spyder. The insert (~0.685 brass) and tips were the same. One of the unusual benefits of a Freak system is it allows holding these things constant across guns. The fit was neither under- nor over-bore.

    Quote Originally Posted by Spider-TW View Post
    Those curves are interesting in that they are such nice bell curves. I have trouble believing that paint defects (or varying marker/barrel defects) would be so smoothly distributed. These look like consistently oblong paint being loaded into the breeches in a perfectly random fashion. Like out of a loader or something.
    That might be a reasonable way to describe paint though. Paint is good, but it's measurably imperfect -- possibly also consistently imperfect. For argument's sake, if the main deformity in the paint is the seam itself, then... what would be the difference between randomly loading that and randomly loading consistently oblong paint?

    And the chrono itself only displays with a granularity of 1FPS, so there's smoothing/bucketing/rounding action already built into the instrumentation itself. Obviously if there were more significant digits, for the same sample size, the thing might not look as smooth.

    Chrono sessions and data for both are online (matter of procedure as writing FPS while shooting takes way too damn long, and I'm just one guy):

    https://www.youtube.com/watch?v=MMtYTwWFNg0
    https://www.youtube.com/watch?v=vo-Ea3bZ1pI

    (Admittedly the Spyder one is not readable as is; I had to run it through a video editor and crank brightness/contrast to read the numbers. But the spreadsheeds should be linked in the descriptions.)

    You guys are all encouraged to, you know, actually run your own testing and add to the available pool of data. I'm just one guy.

    Imagine what would be possible with TWO people actually performing testing! *YAKAWOW*



    Note: Just to clarify, those are actual plot points, not fitted curves.
    Last edited by GoatBoy; 04-11-2017 at 08:20 PM.

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