Grip hole depth

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The Kid
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Grip hole depth

Post by The Kid » July 30th, 2010, 5:33 pm

I've been lurking around here for just a couple of weeks and have learned more than I've learned in my two year pro shop experience. Thanks for all the in depth discussion on everything from dual angle sweet spots to mass bias movement post-drilling and everything in-between.

However, one thing has eluded me thus far: a discussion on depth of hole on changes in RG, total dif., and intermediate dif.

I assume there must be some difference (besides static weights) in drilling finger holes 1.5" and 3" in order to get more thumb weight for a P4 or P3 weight hole. I've done it many times since switching from the traditional layout method to the dual angle. What do you think (know)?

Thanks!

-Steve

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Re: Grip hole depth

Post by kellytehuna » July 30th, 2010, 10:56 pm

First of all, welcome to the site! Like yourself, I've learned far more from this site than I could have imagined.

You actually ask a GREAT question. One I have pondered on myself. It seems to me that while every hole drilled in the ball will raise the RG profile in the general vicinity of said hole, I think the major changes come about when you start hitting the core, due to the differences in density between the shell, the outer core and the inner core.

I read a statement from Mo on this site, or maybe even BBE before they banned him, stating that you manipulate the RG values of the ball by manipulating the density of the core. It stands to reason that the MORE volume you remove from the inner core, the greater the change in the RG profile in that location.

In the case of drilling finger holes deeper (usually the middle finger) to increase thumb weight, if you go beyond, I think its 2" in most cases, you start to remove weight from core as well. HOWEVER, since weight holes are recommended to be AT LEAST 2.5" deep, the weight holes will remove a greater volume of the higher density inner core and therefore result in greater changes in the RG profile and differentials, so the net result is still close to what you were after in the first place.

That's my take on it all, from previous readings and what not. In summary, you raise the RG value in the location of any drilled hole. The changes will more significant if you hit the inner core, especially if you take a lot mass from the core.
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Re: Grip hole depth

Post by elgavachon » July 31st, 2010, 1:33 am

Welcome also
Using P3 and P4 wt holes you raise the total differential as well as the intermediate. In most cases the intermediate raises more than the totals which raises the ratio. But like Kelly explained, drilling the fingers deeper should have the opposite effect. I may be wrong, but I think I remember Mo and Richie discussing this, and Mo showed the actual numbers ( or Steve maybe). The deeper finger holes does lower the differentials; however being able to use the bigger wt hole will raise them more than you lowered them. I took that to mean if you could leave the fingers shallow and still use the wt hole, that would be your first choice. Your second choice would be deeper fingers for a deeper wt hole. Your last choice would shallow fingers with no hole.

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Re: Grip hole depth

Post by steve s » July 31st, 2010, 2:23 am

The closer the pin is to the fingers the more the holes effect the numbers because you will be drilling into the top of the weight block.....Steve S

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Re: Grip hole depth

Post by The Kid » July 31st, 2010, 6:36 am

Thanks for the welcome!

All three of you hit points that align with my own assumptions. I think the deeper the hole, the greater the effect (it seems, negative) on the, what you called "RG profile." Pin location also must be key as, it seems to me, the closer the inner core is to the outer circumference of the ball. More inner core means more differential change.

But in any case, it seems my main reason for concern was dealt with. It does some to be "worth it" to remove finger weight in order to drill the P3-P4 hole.

However, with a larger drilling angle (70*+) the hole could end up further from the grip center than either finger, so the finger holes might have to be drilled deeper to keep static weights within legal limits... correct? In this case, would it still be beneficial if the finger hole ends up removing more mass (inner core especially) than the weight hole?

If so, does it have anything to do with the RG axes that the holes are near (i.e. low RG axis near finger holes and high RG axis near (or in) weight hole)?

-Steve

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Re: Grip hole depth

Post by steve s » July 31st, 2010, 10:09 am

"However, with a larger drilling angle (70*+) the hole " ..... The val angle and pin distance from pap determines the location of the pin to the finger holes...With such a large val angle to get the pin close to the fingers would you really want to use a p3 or p4 hole and have a 70* drill angle? Steve S

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Re: Grip hole depth

Post by The Kid » July 31st, 2010, 3:33 pm

Hmm. Good catch. I suppose it would be a pretty specific situation one would have to be in to face that dilemma.

Rev dominant? Longer pin-to-pap for low axis tilt?

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Re: Grip hole depth

Post by kellytehuna » July 31st, 2010, 3:45 pm

The PAP location plays a huge part in proximity of the pin to the fingers also. You will close to the fingers with lower val angles and shorter pin distances with a PAP in the order of 4" than those with a PAP in the order of 5".

I've found that recently, a good number of my layouts end up with the Pin in the general vicinity of the ring finger. I USED to have a PAP of 5 3/4", 1" up, I now have a PAP of 4 1/2", 1 1/4" up.
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Re: Grip hole depth

Post by steve s » July 31st, 2010, 4:04 pm

You mention your pap moved ..... I have found with in the last couple of years there are a lot of players with new stuff that have a pap that moved aprox 1 inch closer to the grip center...Is this a result of the "flare in the air " syndrome and we are only catching the first oil line? I say this because they also have plastic balls with the thumb hole cracked out because of rolling over it ....I don't think most of them change the way they release the ball that well...Steve S

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Re: Grip hole depth

Post by kellytehuna » July 31st, 2010, 4:26 pm

Mine moved with changes in my release after seeing Mo. I've found that for my PAP stays pretty consistent from ball to ball. I've not checked my PAP on a plastic ball for a while, so I'll do that and see if is the same. I put the ball down pretty much at my toes, so I wouldn't expect their to much change at all.
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Re: Grip hole depth

Post by Mo Pinel » August 8th, 2010, 6:28 pm

elgavachon wrote:Welcome also
Using P3 and P4 wt holes you raise the total differential as well as the intermediate. In most cases the intermediate raises more than the totals which raises the ratio. But like Kelly explained, drilling the fingers deeper should have the opposite effect. I may be wrong, but I think I remember Mo and Richie discussing this, and Mo showed the actual numbers ( or Steve maybe). The deeper finger holes does lower the differentials; however being able to use the bigger wt hole will raise them more than you lowered them. I took that to mean if you could leave the fingers shallow and still use the wt hole, that would be your first choice. Your second choice would be deeper fingers for a deeper wt hole. Your last choice would shallow fingers with no hole.
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