I just bowled a tournament that was on a 45 heavier volume pattern. I had a few 930T's still in stock. So I drilled one with a Double Thumb Drilling for this pattern, surface at 2000 abralon.
This layout for me is a 56° drill angle 4" pin to PAP and 30° VAL angle. Note the pin to PAP and VAL angle are always those numbers on a double thumb. The drill angle varies based on your PAP measurements.
When I was on staff with Track the 930T just didn't really match up for me. With this drilling I have to say this is one of the best rolling balls I have ever thrown on a longer oil pattern.
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Rick Guined
Owner/Operator: New Millennium Proshop:
http://s239.photobucket.com/albums/ff183/Guined/Ebonite Gold Pro Shop
Vise PBA Regional Staff Player
IBPSIA Certified Technician
USBC Bronze Certified Instructor
www.viseinserts.com