Layout tool

Dual Angle Converter

Turn a no-thumb bowler’s PAP and a pin-to-CoG layout into a dual angle layout. Same math our pro shops use. Results update as you type.

Use the converter

Fractions or decimals. Example: 4 7/8 or 4.875.

Bowler

Over from the center of grip. For a down vertical PAP, enter a negative number (example: -1).
Up is positive, down is negative.
Recorded with the layout and shown in the summary. It does not change the numbers.

Ball layout

Enter desired drilling angle
Between 15° and 120°.
Straight line from pin to PAP.
Pin to the center of grip, in half inches.

Center of grip (CoG) to PAP distance

CoG-to-PAP
5
Straight-line distance from the bowler’s center of grip to their PAP, rounded up to the nearest 1/8. It changes with the PAP coordinates.
Layout sum
6 1/2
Pin-to-CoG plus Pin-to-PAP. Must be greater than CoG-to-PAP.

Dual angle conversion

Drilling angle
60°
Your Asym drilling angle, carried through.
Pin-to-PAP
5
Carried through unchanged.
VAL angle
74°
Rounded to the nearest degree.

Reference drilling angles

Where the PSA lands for this PAP and layout. A Sym layout uses the first one.
Where the PSA sits
Angle
PSA to VAL
CG / PSA in line with CoG and pinSym drilling angle
PSA on the VALMinimum Asym drilling angle
PSA on the grip centerline

Ball radius used in the spherical math: 4.2925 in. Distances in inches, angles in degrees.

How to use it

Three numbers in, one layout out

1. PAP

Horizontal is over from the center of grip. Vertical up is positive. Vertical down is a negative number, such as -1.

2. Layout

Choose Sym or Asym. For Asym, enter a drilling angle from 15 to 120 degrees, then pin-to-PAP and pin-to-CoG.

3. Dual angle

Read drilling angle, pin-to-PAP, and VAL angle. The layout sum has to be greater than the CoG-to-PAP distance.

Layout notes

What the numbers mean

What does this converter do?

It turns a no-thumb bowler’s positive axis point (PAP) and a pin-to-center-of-grip layout into a dual angle layout: drilling angle, pin-to-PAP, and VAL angle.

What is CoG-to-PAP?

The straight-line distance from the center of grip to the bowler’s PAP, rounded up to the nearest 1/8 inch. It changes when the PAP coordinates change.

Why does the layout sum have to clear CoG-to-PAP?

Pin-to-CoG plus pin-to-PAP has to be greater than the CoG-to-PAP distance, or the pin cannot reach that PAP. Raise pin-to-PAP or pin-to-CoG until the warning clears.

What is the difference between Sym and Asym?

On a symmetrical ball the converter sets the drilling angle so the center of gravity sits on the pin-to-CoG line. On an asymmetrical ball you enter the drilling angle you want, between 15 and 120 degrees, and the converter carries it through.

What does the PSA warning mean?

If the drilling angle puts the PSA past the vertical axis line, ball reaction can suffer. The converter names the minimum drilling angle that keeps the PSA on the VAL.