Well I think I understand.

Will my ball driller know how large/deep to put the extra balance hole?


I measured my PAP today and it is 4 3/4" right & 1/4" up.

I am having my BW Bite plugged and re-drilled to the 30 degree, 3 3/8", & 30 degree. I figure I have about 700 games on it so no more real harm can be done with a re-drill. I will throw it for the rest of this month before I order the LM Terminator the 1st week of November.


Much thanks again for the Knowledge sharing. It is almost as much fun screwing with (learning) ball dynamics as it is actually bowling.

~ John

The weight hole will depend. If you want to make the reaction stronger (more flare), go for the largest hole possible on the mark CoachJim mentioned. If you need to weaken the reaction a bit, put the hole on the PAP. You can also go in between for different reactions. The site explaining the balance hole system is here: http://www.morichbowling.com/MosCorner/GradientLineBalanceHole/GradientLineBalanceHole.htm

The nice thing about balance holes is that they can be used to tweak the reaction. So, you can have the ball drilled, throw it, and then add or reduce flare as necessary

I think thats why my driller always puts a hole in every ball he drills

Well - I finally have a ball that I can push out to the break point and get it back to the pocket when standing left of center (board 20). Thanks all.
My 30 deg, 3 3/8", 30 deg. re-drill of my BW Bite did the trick. I am going to throw it for another 3 or 4 weeks before I purchase the "Terminator" to see if any deg. tweaks would be appropriate.

On a related topic, when I was having this ball re-drilled in the Pro Shop, it was like pulling teeth for them to understand the Angle-Side-Angle of the "Dual Angle Layout Technique". They have drilled so many balls that they just know how to position the pin and kick out the MB (or not) that they almost couldn't do it. I had to use a protractor and cut a 30 deg. angle on paper to lay over the bowling ball to get them to get the angles right especially the 2nd one over the Pap.

Is there anyone on the board here that can use a CAD program and/or set up a web formula page to print out a "Dual Angle Layout" of ones choosing and hand to a driller to lay over the ball?

The drawing would first need:

1) A fixed line of about 8" long with a circle on top to line up with the pin and the MB.

2) The second line would need to be varied from say 1/2" to 7" touching the first line at the top circle (Pin), with a circle at its other end representing the bowlers Pap.

3) The angle between the 1st & 2nd line would need to be varied between 10 & 90 deg.

4) The third line would start at the Pap circle and be able to be varied to +3" or -3" long for the bowler’s vertical Pap coordinate.

5) The angle between the 2nd & 3rd line would need to be varied between 20 & 70 deg.

6) The forth line (Horizontal Pap coordinate) would be a fixed right angle to the 3rd line (vertical Pap coordinate). This 4th line would need to be varied between 2" and 6" with a fixed 2" extension on the other side of the center of grip.

7) The fifth (and last) line, the grip center line, would be fixed 8" long and centered with a fixed right angle from the forth line (Horizontal Pap coordinate).

It would just be awesome to print out a ball layout with ones Pap to hand over with very little conversation and ridicule!

Please help if able, :-)

~ John

The tough part with that is laying a flat piece of paper on a rounded surface. There will be bumps. What you'd need to do is curve the lines and cut out parts, then tape it back together to create a rounded surface (think the maps of the globe that NASA uses.)

John, I copied this from another recent post that you may have missed and may help you with your ball driller:

Some shops don't know how to measure for angles because they don't have the quarter scale with the degree measurements on it.

To figure out the degrees to distance ratio, 5 degrees = 3/8" at 6 3/4" from the center of the scale. To lay out for degree measurements, draw a line from the pin through the mass bias on balls without a marked mass bias place a mark at 6 3/4" from the pin on this line to be the mass bias line and the p4 location for a max flare weight hole if needed. Next measure over the distance you want from the mb point and make a mark on the ball let's say you want a 45 degree layout from the pap to the mb, that would be 45/5= 9x3/8" = 27/8 = 3 3/8" from the mb. Place a line from the pin to the 3 3/8 mark you just made, then put a mark at what ever distance you want from the pin to pap on this line 4" in your case.

Next we need to figure out how far the pin is from the val (lets use 30 degrees). Start by continuing a line from the pap mark at 4" from the pin to a point 6 3/4" from the pap through the pin. Next we need to figure how far over from this point we need to measure to get 30 degrees, 30 degrees /5 degrees for every 3/8" = 6 x 3/8 = 18/8 = 2 1/4". Measure over 2 1/4" from the point 6 3/4" from the pap through the pin and then make a mark there and draw a line from that point through the pap, and continue it 1/4 past it.

Last we need to figure out where your finger and thumb holes need to be. Measure 1/4" down from the val line we just made from the pap and then make a line perpendicular (90 degrees to) the val through this point 1/4" down from the pap, and place a mark at 5" from the val on this line, that is the center of your grip, from there your ball driller should be able to put the holes in the ball for you.


Edit: CG does this count as a double post

Hi Cgeorg,

I'll have to disagree with you on the flat paper on a rounded surface. After you cut away the extraneous paper, the paper figure left is three pronged. The three prongs are shaped long & skinny and lay on the quarter face of a bowling ball fine.
I drew my 30Deg. - 3 3/8" – 30Deg. Duel Angle layout with my 4 3/4"RT & 1/4" up Pap by hand on graph paper. As of now, I am going to mark my center of grip on the new ball in about 1 second’s time with this paper template then hand the ball over to my driller for drilling. If I have time in the morning after work I'll post a picture of the template on my BW Bite confirming its new drill.

Hi CoachJim,

I had read your post earlier and understood it but did not print it out to take it to the Pro Shop. I’m afraid if I would have tried to explain it to my driller in the heat of battle (when she had a whole bench full of balls to drill) her eyes would have just glossed over and I would have never got my ball drilled. I think the beauty of the Dual Angle drilling method is its ease of use & understanding. The extra math that you posted is amazing but isn't conducive to ease of use for a newbie like me.
I'm thinking the best way to go is to buy one of those quarter scales with integrated protractor and give it to my driller as an early Christmas present.

Thanks for all,

~ John

I wouldn't try to run a Pro Shop without an integrated quarter scale. The reason I had to figure all of this out is we have a make-shift Pro Shop until my ball driller finds a new place and all we have is an old school quarter scale without the markings.

To make things easier you can get a sharpie and start at 3/8" and mark 5 degrees then at 3/4" mark 10 degrees and so forth every 3/8", most places even the incompetent/makeshift ones have an old quarter scale with the numbers worn off, just mark it on that one.

I don't know why some shops think all they need to do is pop holes in a ball, if they can't follow the dual angle system then they probably should be working at the snack bar.

By the way, the paper idea is never going to work, but do what you want.

Hi CoachJim,

Are you up late or up early? Somehow if you say its not going to work I want to believe you. I happen to have my bowling balls in the car tonight at work so I am going to take a break and run out there with my paper template.
You are right about the Pro Shop. It seems to me if I don't have a tool (that is not too expensive) that makes customers happy I would get the tool.


~ John

I don't know CoachJim my paper template looks pretty close to finding grip center. I think its worth a picture for you to evaluate.

~ John