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Author Topic: PSA and Mass Bias (Read 1432 times)

MegaMav

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PSA and Mass Bias
on: July 29, 2005, 05:07:46 AM
what is the difference between Preferential Spin Axis and Mass Bias?

how differently would you place the 2 locator pins on the ball?

assymetrical layout charts mostly show PSA locators to be below the thumb.

and how would the reactions differ from all the different placements of each?

thanks!

Eric
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  • Traumatize

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    Re: PSA and Mass Bias
    Reply #1 on: July 29, 2005, 01:09:40 PM
    PSA and Mass Bias are the same thing.  PSA is just a name manufacturers use to define mass bias.
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    charlest

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    Re: PSA and Mass Bias
    Reply #2 on: July 29, 2005, 02:44:52 PM
    PSA is an axis, a line through the spheroid we know as the ball. One end is usually what is colloquially called the Mass Bias. I have not seen any proper name for the other end. Since there is a Positive Axis Point and a Negative Axis Point, I guess if one end of the PSA is the MB, the other end of it might be termed the Negative mass bias, weight removed from the other side of the core.

    A ball with a high enough (how high is still open for debate; minimum is considered to be .008 by Mo Pinel) mass bias differential will want to spin on its preferred spin axis, of which the Mass Bias is one end, usually placed with reference to the Thumb or X" away from the bowler's PAP. The Mass Bias of these balls remains fixed with the PSA (I believe) even after drilling; that is a feature of Asymmetric cores with a strong enough MB. Symmetric cores have their PSA generally stick near the thumb.

    I think that's close enough. Experts, please feel free to correct my memory; ain't what it used to was.
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    laufaye

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    Re: PSA and Mass Bias
    Reply #3 on: July 30, 2005, 05:23:29 AM
    IMO, PSA Preffered Spin Axis make a lot more sense.

    oh, PSA or MB same thing.
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    charlest

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    Re: PSA and Mass Bias
    Reply #4 on: July 30, 2005, 05:24:17 PM
    quote:
    IMO, PSA Preffered Spin Axis make a lot more sense.

    oh, PSA or MB same thing.
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    Laufaye


    excuse me. Since when is a line and a point "the same thing"?
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