Hey bts,
In the big picture sense, it's just a matter of understanding what gravity does to controlling weights in an object and everything is tied in mathematically. Quick example:
Ball circumference = 27 inches..then half of that =
Half of ball = 13 1/2 inches...then half of that =
Quarter of ball = 6 3/4 (generic mass bias distance)...then half of that =
Leverage point 3 3/8
A weightblock will always want to pull towards gravity and that motion is known as its PSA (preferred spin axis) or as I refer to it, it's resting point. The closer we place a weightblock to this position, the faster it will rotate there. The farther away we place it, the longer it will take to rotate there. So a pin distance below 3 3/8 will turn down faster (roll sooner) vs a pin distance placed above 3 3/8 (roll later).
Mass Bias is the heaviest or densest part of the weightblock that is closest to the surface of the ball. It's another controlling weight (if >=.008) that affects reaction. This helps control reaction shape or breakpoint, still working around our magic number of 3 3/8.
Here's a link to some info put together from some of the "inmates" here (as Charlest's puts it
). Hope this helps some...
http://home.mchsi.com/~s-cross-7-28-71/FAQ.htm--------------------
Rick Leong
Ten Pins Pro Shop
Track Intl. - Amateur/Pro Shop Staff
Vise Inserts Staff
Edited on 1/24/2005 1:05 PM
