Does Static weights or CG marking position matter?
- Thread starter tonx
- Start date
jason_doust
The Bowling Geek
It is interesting viewing. But as (Bruns)Nick himself points out, pin location as it relates to the bowlers axis of rotation and extra hole are the big determinants. (Although not as big as surface, but that's off topic.) As the extra hole location is usually determined by the CG location (to be within USBC tolerances), then CG location can matter a great deal. I agree that the ½ oz of side weight doesn't matter much, but it may be the bit extra imbalance you require to get a big enough hole in the ball to make the difference you're after. (The big extra hole has been known to turn a ball from skid-flip zero to true roll hero.)
Additionally, the layouts used put the mass bias a similar distance (therefore similar radius of gyration) from the axis, be it positive or negative axis at flare. As the ball precesses, the MB maintains a roughly equal distance to the moving axis, just on opposite poles. Sketch it out and you'll see what I mean.
A third ball with the CG and MB placed north west, so that the track precessed toward having the MB on the axis, as opposed to the previous two where it was moving away would give this interesting experiment more meat to chew. I suspect it would give the subtly different results. All three balls would be quite different if they were drilled back to legal. (Especially when you tracked over the X-holes.
)
Cheers,
Jason
p.s. If I've done anyone's head in with this, I apologise. I am a self confessed bowling ball nerd.
Additionally, the layouts used put the mass bias a similar distance (therefore similar radius of gyration) from the axis, be it positive or negative axis at flare. As the ball precesses, the MB maintains a roughly equal distance to the moving axis, just on opposite poles. Sketch it out and you'll see what I mean.
A third ball with the CG and MB placed north west, so that the track precessed toward having the MB on the axis, as opposed to the previous two where it was moving away would give this interesting experiment more meat to chew. I suspect it would give the subtly different results. All three balls would be quite different if they were drilled back to legal. (Especially when you tracked over the X-holes.
)Cheers,
Jason
p.s. If I've done anyone's head in with this, I apologise. I am a self confessed bowling ball nerd.
tonx
New Member
Jason, Great observations!
Firstly, even though typically a ball with limited MB influence has a theoretical or vitual mass bias 6 3/4 through cg, a MB strength is measured in spin time, which can be measured using a Determinator Scale. The Uranium HRG definately doesn't have a mass bias that registers within even as much as 15seconds on the scale so the CG placement is no indication of the MB placement.
The XH definately matters in depth, width and pitch. Yes, the static weights are relevant to the XH placement, however this Video as well as Brunswicks original Throwbot video is to show that the actual imbalances in the ball have 0-1% influence in ball reaction.
Modern day laying out of symmetrical bowling balls are taught by Ebonite, Brunswick and Storm to target approx 3/4 oz side weight to give the XH impact on flare path if wanted, yet not needed to keep the ball within USBC regulations.
Of course if you wish for the XH to play a more defined role in the balls reaction, then target more, but if a driller is targetting a ball reaction THAT specific, they better be doing it for a very advanced bowler, and know that the bowler will know when best to use it. (IE: Rico, Semi-pin axis, Ebonites TJ-trick layout, 235 degree etc etc)
What people fail to realise, is the REAL cg of a bowling ball is less than a couple of millimetres from the centre of a ball, even with HUGE core offsets. The CG mark on a bowling ball should be renamed Top weight indicator.
This video was originally made as a little fun experiment, and to prove to Lane#1 (who believe the CG marking placement is more important than pin placement) that the placement of the CG mark to create LARGE static imbalances as almost no influence on a bowling balls reaction.
Hope you enjoyed the video
Firstly, even though typically a ball with limited MB influence has a theoretical or vitual mass bias 6 3/4 through cg, a MB strength is measured in spin time, which can be measured using a Determinator Scale. The Uranium HRG definately doesn't have a mass bias that registers within even as much as 15seconds on the scale so the CG placement is no indication of the MB placement.
The XH definately matters in depth, width and pitch. Yes, the static weights are relevant to the XH placement, however this Video as well as Brunswicks original Throwbot video is to show that the actual imbalances in the ball have 0-1% influence in ball reaction.
Modern day laying out of symmetrical bowling balls are taught by Ebonite, Brunswick and Storm to target approx 3/4 oz side weight to give the XH impact on flare path if wanted, yet not needed to keep the ball within USBC regulations.
Of course if you wish for the XH to play a more defined role in the balls reaction, then target more, but if a driller is targetting a ball reaction THAT specific, they better be doing it for a very advanced bowler, and know that the bowler will know when best to use it. (IE: Rico, Semi-pin axis, Ebonites TJ-trick layout, 235 degree etc etc)
What people fail to realise, is the REAL cg of a bowling ball is less than a couple of millimetres from the centre of a ball, even with HUGE core offsets. The CG mark on a bowling ball should be renamed Top weight indicator.
This video was originally made as a little fun experiment, and to prove to Lane#1 (who believe the CG marking placement is more important than pin placement) that the placement of the CG mark to create LARGE static imbalances as almost no influence on a bowling balls reaction.
Hope you enjoyed the video
