Understanding the acronyms and abbreviations you will use in the spec sheet

1. On the spec sheet you will see 4 options :   
2. "F" for Full span 
3. "C" for Cut to Cut 
4. "O" for Outer to cut
5. "H" for Hole to Hole
6. see the picture 

   

7. In a conventional drilling with no inserts, F (Full), C (Cut to Cut) and H (Hole to Hole) are all exactly the same. It's possible that you could use the O (Outer to Cut) if you have chosen to use a pre-sized thumb insert
8. In a finger tip drilling, we will determine the  "F" full span 1st (see example in the picture below):

   

9. The "C" Cut to cut is the measurement from the edge of the actual thumb hole to the edge of hole for the finger inserts. By definition, the Cut span is the full span - the thickness of the inserts. If not using inserts then the full span is the same as the cut to cut span.
10. No Inserts example :

    

11. If using inserts you can select the type of inserts determined by clicking the "Inserts" section see the picture below :

    

    When the selection of the insert type and size is made, Spectre will automatically calculate the cut to cut spans and the drill hole size required for that insert. Example:

    

12. The "O" Outer to Cut section is measured manually when the ball is completely drilled. This is to make it easier the next time you drill a ball for the same bowler. The Measurement should be shorter than your "C" ( Cut to Cut ) Span .
13. Select the type of swicth grip use on "Thumb Insert Type" section  

    

14. The option of switch grip are : Turbo Switch Grip , JOPO Interchangeable or Vise-IT . EX: 

    

    

15. JOPO Interchangeable and Turbo Switch Grip require the use of a 1 1/2"  drill bit to accommodate the Outer sleeve. See the picture below . You will find on "O.D" section of the thumb .

    

    

    

16. If you  use Vise-IT system four drills bit is available see the picture below 

    

    

17. The "O" (Outer to Cut) measurement is the distance from the edge of the outer sleeve ( Turbo or JOPO) or top sleeve ( Vise-it System) to the edge of the hole of fingers see the example below:

    

    
    
18. The "H" ( Hole to Hole) is the measurement from the edge of the drilled hole for the fingers to the edge of the drilled hole for the thumb insert. In this example, we take the measurement of the "O" span minus the thickness of the outer sleeve (1/16")  See example:

    

19. If you are using any lateral pitch on the thumb, you add it manually on "Right" of "Left" section based on what is required Example: