CG for symmetrics and finger holes (to deep)

This forum is for topics related to pro shop operation and bowling center maintenance.
Usual topics include: shop gear, fitting, drilling and lane maintenance.

Moderator: Moderators

Post Reply
driller
Member
Member
Posts: 5
Joined: April 3rd, 2016, 9:15 pm
Preferred Company: brunswick

CG for symmetrics and finger holes (to deep)

Post by driller » January 19th, 2022, 6:21 pm

Hello,
I have 2 questions to ask hereby that are connected to layouts.

1.Whats the reason that the finger holes are very often drilled into the core? Shouldn't it be better to not modify the core?
If they are not deep as that you can plugg and re drill with different layouts without any impact on the core.

2.As I have seen from Mo, the impact of CGs position have no impact at all for symmetric cored balls.
Does that mean that a ball with pin between the fingers (up or down) will behave the same for a lefty as a right hand player? (if player style parameters are equal) independent of side weight ex. +1 ounce for RHP or -1ounce for LHP? Means a left hand player can drill the grip at same position as the right handed after plug? if needed just change finger holes position for pin replacements if needed?

Both questions are connected to modify the core in balls as less as possible.

User avatar
MegaMav
Moderator
Moderator
Posts: 4648
Joined: April 27th, 2007, 5:00 am
THS Average: 225
Sport Average: 200
Positive Axis Point: 4 15/16 Over 7/8 Up
Speed: 15.25 MPH - Camera
Rev Rate: 350
Axis Tilt: 14
Axis Rotation: 45
Heavy Oil Ball: Radical - Informer
Medium Oil Ball: Brunswick - Knock Out
Light Oil Ball: Radical - Bonus Pearl
Preferred Company: Radical Bowling Technologies
Location: Malta, NY

Re: CG for symmetrics and finger holes (to deep)

Post by MegaMav » January 19th, 2022, 8:45 pm

driller wrote:
January 19th, 2022, 6:21 pm
Hello,
I have 2 questions to ask hereby that are connected to layouts.

1.Whats the reason that the finger holes are very often drilled into the core? Shouldn't it be better to not modify the core?
If they are not deep as that you can plugg and re drill with different layouts without any impact on the core.

2.As I have seen from Mo, the impact of CGs position have no impact at all for symmetric cored balls.
Does that mean that a ball with pin between the fingers (up or down) will behave the same for a lefty as a right hand player? (if player style parameters are equal) independent of side weight ex. +1 ounce for RHP or -1ounce for LHP? Means a left hand player can drill the grip at same position as the right handed after plug? if needed just change finger holes position for pin replacements if needed?

Both questions are connected to modify the core in balls as less as possible.
1a. Driller preference at this point. It used to be to balance statics without a balance hole or a industry misnomer about significantly altering ball reaction.
1b. Not modifying the core is usually meant for certain core designers and their egos.

2a. No. Each player is different and how they release the ball along with their PAP is different, so the layout will be different in relation to that.
2b. No, again, each player is different.

Drilling into the core of the ball will either enhance to reduce core/ball dynamics, it depends how it's drilled.
“When you prepare for everything, you’re ready for anything.” - Bill Walsh

driller
Member
Member
Posts: 5
Joined: April 3rd, 2016, 9:15 pm
Preferred Company: brunswick

Re: CG for symmetrics and finger holes (to deep)

Post by driller » January 20th, 2022, 7:47 am

thanks for reply,
At answer 2a, its not take into account of my information. text:(if player style parameters are equal) read instead: theoritical mirrored player.
To simplify the question:have +1 ounce or -1 ounce any impact at all? such as earlier or delayed rolling?
or more simplyfied:
If the pin is symmetrical placed between the fingers, the negative OR positive side weight have no impact at all?

TomaHawk
Pro Shop
Pro Shop
Posts: 518
Joined: July 19th, 2010, 3:28 pm
Location: Michigan

Re: CG for symmetrics and finger holes (to deep)

Post by TomaHawk » January 20th, 2022, 7:18 pm

With symmetric bowling balls, the method for finding the bottom end of the core is vague at best. We'll draw a line from the pin, through the cg, and mark a point 6 3/4" from the pin. Measuring the static zero point of a bowling ball, before drilling, is of little consequence. We still won't know the orientation of the block, only an x-ray could reveal the exact location. Therefore, drilling a symmetric is not exact science.

If you're asking, would a 1" variance in the orientation of the block either to the positive side or negative side of the thumb make a difference? The answer would be yes. That's a 2" variance, but more importantly, 1" negative would place the bottom of the block closer to the track.

Post Reply