Mo Fact Sheet
These are some quick facts posted by mo on various parts of the forum.
- For low tilt bowlers, on asyms., use pin to PAP distances of 2 3/4" to 4" to get the ball to change direction and read friction. Use 4" to 5" pin to PAP distances when you want to play straighter.
- For high tilt bowlers, don't use 3" to 4" pin to PAPs on asyms. unless there's lots of friction, or you're using a ton of surface with a big, strong balance hole. Use 4" to 5" pin to PAPs to read friction and 5" to 6" pin to PAPs to play straight. Another example of the need for accurate delivery specs.
- In reality, the coverstock, surface sanding, ball total diff., and pin to PAP distance control the length of the first transition. The layout and balance hole location, which affect the strength of the PSA affect the distance from the first transition to the second transition. That's basically the intermediate diff. of the drilled ball.
The smaller VAL angle increases both diffs., but it increases the intermediate diff. much more than it increases the total diff., thereby increasing the diff. ratio. The smaller diff. ratio causes the longer hook zone (slower transition).
Lowering the pin towards the midline lowers both diffs., but lowers the intermediate more than the total diff., thereby decreasing the diff. ratio.
60x20 to 60x50 is a big change. I usually make 10* changes. P4 balance holes change diffs. more than small angle changes. Try to get it a close as possible with the layout and, then, tweak it with the balance hole. That's the best system.
(For symmetrical balls): You're getting pretty good. Put the balance hole on the VAL 2" below the midline, if needed. Drill it 2 3/4" deep. As you make it bigger, it will pull the PSA towards it and reduce the drilling angle to get the ball to start up a little sooner.
For balance holes close to the thumb hole: The pitch of the balance hole plus the distance that the center of the hole is from the edge of the thumb assembly must equal 2 1/2" plus whatever lateral pitch toward the balance hole the thumb hole has. Voila!
When the fingers are over 3" deep, don't go any deeper than 2 3/4" on the balance hole! The holes will meet, if you drill the balance hole too deep.
Staying behind the ball causes it to track high. Specifically, lack of axis tilt. Staying in the thumb too long causes it to track very close to the thumb. That's the real skinny.
Reply to a two handed bowler who was clipping the edge of his thumb hole: Stop chasing your tail! Let's adjust your finger pitches since you don't use your thumb. Drill your fingers 7/16" left by 1/4" forward on your middle finger and 7/16" right by 3/8" reverse on your ring finger, if you're right handed. Now measure your initial axis tilt and your PAP and post that info. We'll go from there. No more hand grenades at 20 paces! Use your normal thumb hole location.
- This quote taken from viewtopic.php?f=6&t=4557&p=36474#p36474 (see # 19)
ALL bowling balls with migrate along the RG contour of the Bowler's PAP. That's governed by the laws of the universe. Therefore, in order to create a unique migration path, you must create a unique RG contour for that ball. ALL balls have RG contours that use the low and high RG axis as the centroid for the RG contours. The higher the differential ratio, the more of the RG contours that are centered around the high RG axis, and the flatter those ellipses. That's just pure science and math.
- Don't worry about the cg. No problem. CGs don't mean a thing (to) ball motion as long as the ball has legal statics. .... NEVER put balance holes below the thumb. Too much of a chance of flaring over it.
*With Scotch Brite pads, it's all about the pressure you use with the pad. Burgundy results in 400 to 800 depending on the pressure. Grey results in 800 to 1500, again, depending on the pressure used.
Using scuff pads is not an exact science, but this is usually done during practice when the ball you want to use is not reacting enough. After the bowling is done, I always recommend using a spinner to return the ball to its' normal surface.
On a symmetrical ball drilled without a balance hole, the PSA (high RG) axis ends up very near the thumb. That puts the PAP near the intermediate RG axis on a vast majority of bowlers. Putting a balance hole in the PAP, which is near the int. RG axis, raises the RG of the int. RG axis. That decreases the int. diff., which makes the ball more symmetrical. That's what blueprint's excellent attachment shows. This explanation is for those who have math phobia.
Increasing the reverse in the middle finger actually helped to lower your tilt. Changing pitches changes the resulting ball motion. If you have to change the grip to accomodate issues like this, CHANGE THE SPAN FIRST TO RELIEVE THE PRESSURE, NOT THE PITCH, UNLESS YOU WANT TO CHANGE THE ROLL!
Sand 4 ways thoroughly with the first grit and sand two ways quickly with the second grit to do the "skip a grit" procedure.
Stretching spans tends to decrease tilt as does reverse in the fingers.
- Reply to a two handed bowler who was clipping the edge of his thumb hole, from viewtopic.php?f=7&t=4798
Stop chasing your tail! Let's adjust your finger pitches since you don't use your thumb. Drill your fingers 7/16" left by 1/4" forward on your middle finger and 7/16" right by 3/8" reverse on your ring finger, if you're right handed. Now measure your initial axis tilt and your PAP and post that info. We'll go from there. No more hand grenades at 20 paces! Use your normal thumb hole location.
Why is it that Mo doesn't recommend pin to pap distances of anything past 5.5 ?
Here's the real reason. The low RG axis can move when the ball is drilled. Using a pin to PAP distance of > 5.5" might result in the real low RG axis moving to a pin to PAP distance > 6 3/4". That may cause the ball to flare in bad places, causing the ball to flare over some drilling holes. NOT GOOD!
I'll try to make this plain. All balls are delivered with more axis rotation than tilt. Cannot be any other way. The laws of physics dictate that. The ball loses both rotation and tilt. The ball loses rotation faster than it loses tilt until tilt = rotation. That occurs at the second transition. FACT! During the roll phase (after the second transition) the ball loses rotation and tilt at the same rate until the ball hits the pins. That should keep your mind busy for a while.
Phasing is a function of porosity. Change in temperature causes it to absorb moisture. I light wipe with a little acetone, or a hair dryer will get rid of it. BALLS THAT PHASE EASILY HOOK!
This is what a vast majority of low tilt players don't understand. This is the magic. Fingers on the inside hemisphere of the ball at the top of the swing. Fingers move across the back of the ball until the hand reaches the "Nike Swoosh" position at the end of the follow thru. If the wrist is cupped at the top of the swing, it MUST be unloaded by the time of the release.
The reason we use a higher angle ratio for symmetrical balls is that drilled symmetrical balls lose tilt at a rate almost double the rate that asymmetrical balls lose tilt as both types of balls go down the lane.
You're very close. With a symmetrical ball, the PSA will be very near the thumb hole after drilling until the balance hole is drilled. We can change the mass properties of the drilled ball about 40% with layout and balance hole. With an asymmetrical ball, we can put the PSA whereever we want, and change the mass properties of the drilled ball by as much as 84% with layout and balance hole.
Conclusion: Syms are easier to drill and less versatile, making ball selection a premium. Asyms are more versatile and can provide stronger motion, but are dependent on the skills of the ball driller because they are more sensitive to the layout and balance hole.