Hello all, coming back to bowling after 2 years, I have remembered what pin to pap does etc etc, but what in the world does the PSA measurement have an effect on the reaction? sorry for the noobie question

Thanks

Bret

Typically on symmetric balls with no weight hole if the drilling is a pin up drilling the PSA ends up being the thumb hole. The PSA typically stays 6 3/4" from the pin towards the thumb hole, the higher up the pin is moved, the higher the PSA will still move staying close to 6 3/4" from the pin. If you add a weight hole, depending on the location the PSA then shifts towards the weight hole. (if the hole is of any decent  size and depth)

On pin down drillings the PSA ends up being 6 3/4" from the pin through the thumb hole, roughly within a half inch either side of the line. This will then shift if a weight hole is added towards the location of the weight hole.

The smaller the drilling angle is when using the dual angle layout(closer to your val) the sooner the ball will roll. The larger the drilling angle is( further away from you val/closer towards your thumb) the later the ball will roll.

With symmetric bowling balls the only way to get the PSA closer to your val is to add a weight hole that will cause it to shift that direction.

Great stuff, all above.

Please elaborate on the Z axis effect of the mass bias or PSA?

Regards,

Luckylefty

So, on a symmetric ball, if I want to drill a P2 or P3 weight hole, I would use my axis as the P1 location and the center of the thumb hole as the MB/P4 location? Thanks for the help.

The PSA (preferred spin axis) is commonly referred to as the mass bias or there is more mass on one side as opposed to the other. Symmetrical core references the 2 sides mirroring themselves, the pin/core is defined by the X axis or low RG and 6 3/4" around the hemisphere would be the Y axis or high RG. In asymmetrical core balls the PSA or mass bias, there is a mass on the Z axis. A PSA strength of less than .01, generally has minimal overall effect on ball motion.
Also, the PSA influence is dependent on the overall flare created by the primary pin, i.e. if the pin is placed at 3 3/8", which is the highest potential placement to create flare...the PSA will have less effect; it primarily effects down lane motion similar to a weight hole in a symmetrical core ball 

I thought that there were studies done that show for Assy balls, that you can get increased flare going greater than 3 3/8.  I'm not trying to be confrontational, just saying that your statement isn't always correct.

Ok you can believe what you believe and I'll believe what I do,..but it's called physics and you can debate it all you will...I'm good with it

Actually, I think the point of bringing up physics is that it can't be debated.  So with that said, dr3w is correct.


http://wiki.bowlingchat.net/wiki/images/5/58/Bowling_Ball_Track_Flare_Explained.pdf

http://bowlingchat.net/forum/viewtopic.php?f=13&t=6000&sid=ce8580f227cc2f0e0951175cccc7e9df&start=0

charlest, thanks for the Wikipedia pro shop link. I enjoyed reading the details, but I am starting to believe that an engineering degree from MIT would be a major help!!!