BallReviews

General Category => Drilling & Layouts => Topic started by: J_w73 on November 16, 2017, 01:42:05 PM

Title: Forward ball rotation and hook
Post by: J_w73 on November 16, 2017, 01:42:05 PM
There are a couple guys in my leagues that have a lot of forward rotation and very little axis rotation.  They are pretty high rev players and their ball seems to have a lot of motion for how little they get around the ball.  Can someone explain the physics of this?  Can the ball hook at a greater angle than it is rotating? 
Title: Re: Forward ball rotation and hook
Post by: itsallaboutme on November 16, 2017, 05:56:15 PM
No, the angle the ball is hooking is an illusion.  Go down the lane and watch somebody throw the ball to get a different perspective.   
Title: Re: Forward ball rotation and hook
Post by: bergman on December 05, 2017, 12:08:54 AM
Agreed. For a ball to hook there has to be axis rotation that is >0.  However with some asymmetric core shapes, it is possible to achieve some "hook" even with zero axis rotation.
Title: Re: Forward ball rotation and hook
Post by: J_w73 on December 05, 2017, 12:35:17 AM
Agreed. For a ball to hook there has to be axis rotation that is >0.  However with some asymmetric core shapes, it is possible to achieve some "hook" even with zero axis rotation.

There is more than 0 degrees of axis rotation, but not more than 45.. probably around 20 to 30 degrees, but yet the ball seems to hook at a greater angle than it should.

Title: Re: Forward ball rotation and hook
Post by: spmcgivern on December 05, 2017, 09:18:36 AM
The ball stops hooking when the rotation is 0 in the direction it is traveling.  High rev bowlers with minimal rotation are able to maintain that rotation through the entire lane.  Friction eventually wins and the rotation is reduced to zero. 

If fewer revs are imparted on the ball, the distance traveled before reaching 0 rotation is shorter.  More revs will increase this distance.
Title: Re: Forward ball rotation and hook
Post by: HackJandy on December 05, 2017, 05:01:06 PM
So if someone is a low track, high axis tilt (>25), low axis rotation (<50), high speed bowler (>18mph) they are nearly certain to be an down the boards bowler huh?