Author Topic: drillers... explain to me pin placement. (Read 5488 times)

DonSVO · « **on:** January 17, 2007, 06:36:39 AM »

maybe I am being too simple... but I always equated pin distance from CENTER OF GRIP to equal length before reaction. further from CofG north the later the ball reacts. Pin over fingers reacts later than pin under fingers, etc.

What happens to length when the pin is in the Center of grip, or lower? Would it be better to think in terms of pin from PAP? If so, where does the location from the Center of Grip from the pin come in? if I have the pin 2" above my fingers and 4" from my PAP... i can also have the pin 4" from my PAP but just a hair under and left of my Center of Grip. How would each react?

Someone, explain this. I am looking at new ways to drill up equipement. I like going to my driller with some wild-as-all-get-out layouts and ask them what they think. I believe that my understanding of pin placement is very fundamental. Does the pin from CG matter as much as pin from PAP? which is more important?
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Brunswick and Lane #1: there is no other. Well... maybe a few Storms... and a One. Did I mention Roto Grip yet?

01/11/07 - 202, 159, 203 = 564
Running Avg (48 games): 190

azus · « **Reply #1 on:** January 17, 2007, 02:44:32 PM »

If you out the pin lower than the center of the grip, you will reverse the flare. Center of grip is the lowest place you can put the pin, a layout where you put pin in CoG is the Rico layout.
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shelley · « **Reply #2 on:** January 17, 2007, 02:47:52 PM »

The height of the pin above the midline (or center of grip) raises or lowers the effective RG of the ball. Higher pins result in a higher effective RG (RG about what axis I don't know, probably the initial spin axis, through the PAP), giving length and backend. Lower pins result in lower effective RG values, giving earlier roll and a smoother reaction.

Putting the pin 2" above your fingers and still 4" from your PAP means you have a really goofy PAP. That's probably not the case unless you're really Mike Fagan.

Both the pin-to-PAP distance and the height of the pin above the midline affect the length you get from the ball. They're not totally independent since moving the pin vertically above the midline tends to increase pin-to-PAP distances

SH

leftehh- LG · « **Reply #3 on:** January 17, 2007, 02:57:17 PM »

quote:
Think of the core like a Football.

The very top point of the football is where the pin is.

When we lower the pin, we make the core shorter laterally. So when we throw the 'football' normally, it spins very fast and very easily. Think of this like the lower RG of the core.

When the pin is placed higher, it's as though the football is thrown end over end, it doesnt have the ability to spin up as fast. Think of this like using the higher rg value of the core.

Its a basic explination, but if you can visualise this, it may help a little.
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but wouldnt the core tumble end over end anyways if the pin is placed in the same quadrant lets say like your ring finger? whens its higher its still tumbling in the same shape as if you put the pin lower. What I am saying is no matter what its still spins of your hand the same way..how does it really change the reaction. How does the it spin up faster especially with only like 2' in diff in the core placement. Im not arguing just asking.
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Edited on 1/17/2007 3:58 PM

JohnP · « **Reply #4 on:** January 17, 2007, 04:39:08 PM »

First, let's get our terminology straight. CG is center of gravity. GC is grip center. The important distance for reaction is the distance between the pin and the PAP. That distance determines the percentage of the ball's flare potential that is used. Pin on the PAP (0" pin to PAP) or in the track (6 3/4" pin to PAP) gives essentially no flare, 3 3/8" pin to PAP gives max flare. From 3 3/8" pin to PAP to 0" pin to PAP, the ball breaks earlier. Going the opposite direction, the ball breaks later. Pin locations higher above the grip midline cause the ball to break slightly later, lower breaks slightly earlier. Pins below the midline can reverse the flare (depends on the core and balance hole location), but that won't affect a low tracker. -- JohnP

DonSVO · « **Reply #5 on:** January 17, 2007, 05:42:02 PM »

quote:
First, let's get our terminology straight. CG is center of gravity. GC is grip center. The important distance for reaction is the distance between the pin and the PAP. That distance determines the percentage of the ball's flare potential that is used. Pin on the PAP (0" pin to PAP) or in the track (6 3/4" pin to PAP) gives essentially no flare, 3 3/8" pin to PAP gives max flare. From 3 3/8" pin to PAP to 0" pin to PAP, the ball breaks earlier. Going the opposite direction, the ball breaks later. Pin locations higher above the grip midline cause the ball to break slightly later, lower breaks slightly earlier. Pins below the midline can reverse the flare (depends on the core and balance hole location), but that won't affect a low tracker. -- JohnP

Ok, that's the kind of answer I was looking for. So if I stuck the pin on my centerline, and moved the pin out towards my PAP to increase flare, what would the relation to CG matter? How would CG affect reaction in this instance? WIth a pin in this area, what kind of ball reaction could I expect? Would moving it towards the PAP along the centerline affect the early or lateness of the ball's reaction?
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Brunswick and Lane #1: there is no other. Well... maybe a few Storms... and a One. Did I mention Roto Grip yet?

01/11/07 - 202, 159, 203 = 564
Running Avg (48 games): 190

JohnP · « **Reply #6 on:** January 18, 2007, 10:05:21 AM »

quote:
Ok, that's the kind of answer I was looking for. So if I stuck the pin on my centerline, and moved the pin out towards my PAP to increase flare, what would the relation to CG matter? How would CG affect reaction in this instance? WIth a pin in this area, what kind of ball reaction could I expect? Would moving it towards the PAP along the centerline affect the early or lateness of the ball's reaction?

Back to terminology -- The grip centerline is the vertical line from the center of the thumb hole through the center of the bridge. The line perpendicular to the centerline through the GC is called the midline. I think your question relates to the pin being on the midline instead of the centerline, since it makes no sense the way you've written it.

For modern balls with symmetric dynamic cores, the cg location (and thus the static weights) have only a minimal affect on ball reaction. Of course, it is still necessary to meet USBC static weight limitations, so cg location will allow and/or require use of a balance hole for legality. Location of this balance hole does affect ball reaction. For balls with asymmetric cores, the cg is ignored, the mass bias is positioned instead. Then the static weights are checked to see if a balance hole will be required for legality.

quote:
so is a longer pin better or easier to drill
i mean is there more possabilities to drill
if the pin was like 4 inches could you leave cg in gc
and put pin out to 4 inch from pap

The answer to these questions depends on the customer's PAP location and the layout desired. If these require the pin to be above the fingers and the cg to be near gc, then yes - a longer pin out would be easier to drill and probably wouldn't require a balance hole. However, if they require the pin to be below the fingers and the cg to be near gc, then a ball with a shorter pin out would be more appropriate, especially if you want to avoid a balance hole. It is best to determine the layout before the ball is selected so the proper pin out and top weight can be specified. -- JohnP

shelley · « **Reply #7 on:** January 18, 2007, 10:16:03 AM »

quote:
so is a longer pin better or easier to drill
i mean is there more possabilities to drill
if the pin was like 4 inches could you leave cg in gc
and put pin out to 4 inch from pap

2-3" pins are easy to drill because they're very versatile. You can put the pin higher or lower than the finger line without moving the CG really far away from the midline (creating excess finger or thumb weight in the process). But you couldn't necessarily put a 4" pin far below the fingers because most of the time, the CG will be too low. Likewise for a 1" pin above the fingers. There are tricks to get around that, like drilling the fingers or thumb deeper to compensate.

SH

MI 2 AZ · « **Reply #8 on:** January 18, 2007, 07:33:05 PM »

Here are some reference sites that may help:

http://www.bowlingfans.com/jeff/ballreactionbasics.html

http://www.ebonite.com/techcenter/positiveaxispt.php

http://www.ebonite.com/techcenter/pinposdynreact.php

http://www.rollrite.co.uk/secrets.php

http://tunedballmotion.com/Layout.htm
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Author Topic: drillers... explain to me pin placement. (Read 5488 times)

DonSVO

drillers... explain to me pin placement.

azus

Re: drillers... explain to me pin placement.

shelley

Re: drillers... explain to me pin placement.

leftehh- LG

Re: drillers... explain to me pin placement.

JohnP

Re: drillers... explain to me pin placement.

DonSVO

Re: drillers... explain to me pin placement.

JohnP

Re: drillers... explain to me pin placement.

shelley

Re: drillers... explain to me pin placement.

MI 2 AZ

Re: drillers... explain to me pin placement.