BallReviews
General Category => Drilling & Layouts => Topic started by: iBrettowski on November 21, 2012, 07:19:59 AM
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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
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On symmetric cored balls, the PSA may have hardly any effect until you start to put weight holes in the right place. (In fact, most symmetric cored balls may not wind up with a true significant PSA until they have a proper weight hole.)
On asymmetric cored balls, the placement of the PSA, or what is termed the Drill angle, can have a very large effect on the ball motion.
This can turn into a long complex discussion. I suggest you read some reference material with good, plain-spoken details. This is a good starting point: http://wiki.bowlingchat.net/wiki/index.php?title=Proshop_Information#Drilling (http://wiki.bowlingchat.net/wiki/index.php?title=Proshop_Information#Drilling)
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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.
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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
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Great stuff, all above.
Please elaborate on the Z axis effect of the mass bias or PSA?
Regards,
Luckylefty
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X axis is height, Y axis is width and Z axis is depth
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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.
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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.
P1 is now 6 3/4" from the PSA on the VAL
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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.
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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
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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
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If your referring to drilled vs undrilled then yes. When you drill the ball it changes the core dynamics shifting the low rg and high rg axis from their original location.
The max end result mentioned would be 3 3/8" So if you started with a pin at 4" from your pap and drilled the ball depending on the layout the pin/low rg axis would shift and end up closer to the 3 3/8" range after drilling.
There was something posted showing that on strong asymmetric bowling balls that having the pin in the 5.5" range from your pap vs symmetric drilled balls yielded different results. The asymmetric ball had an increase in flare vs the symmetric. I'm not sure it was greater then being at 3 3/8" just greater for strong asymmetrics vs mild asym or sym balls.
There is a link to the pdf download at the beginning of the topic
http://forum.bowlingchat.net/viewtopic.php?f=13&t=6000&sid=31576298b509a548c0f18c84663fd1f9
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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!!!
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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!!!
Not at all. It just takes time to get acclimated to the phraseology and knowing what they mean; then applying it. Yes, it seems complicated at first, but once you get used to it, you'll become used to applying the principles more easily. It's like any other subject. The more interested in the subject you are, the easy it is to understand, then the easier it is to understand the principles involved.
Learn the basics first; apply them step by step. Eventually the light bulb will go off in the cartoon word balloon above your head. Then you'll be comfortable.